How to add trailing light effect to finger tips?

You can achieve this by using particles to trace out the path of the motion and converting each particle system into a Curve object. The curves can then be used to draw the trails and animated using keyframes to match the motion.

Start by adding particle systems to the mesh. It's important to have a separate particle system for each 'trail'. The order the particles are emitted will control the order of the points in that trail.

There are two ways of achieving this.

Create a mesh with a single vertex and add a particle system. This can then be duplicated, positioned, and parented to the moving mesh so that it follows the motion. You can create as many of these 'trace' objects as are required.
Emit the particles directly from the mesh being traced. It's important that each particle system emits from a single vertex - so use Vertex Groups to limit the emission for each particle system, adding a particle system for each.

Ensure the particle systems are set to emit the particles with no initial velocity and that the relevant Field Weights are set to zero so they are not affected by any forces present. This should result in the particles 'hanging' at the point they are emitted.

Once you have the emitted particles, open a Text Editor window and paste the following python code :

import bpy

def particles_to_path(objName, tracks=1, particleSystem=0, curveResolution=0, bevelDepth=0.1):

    object = bpy.context.scene.objects[objName]

    particles = object.particle_systems[particleSystem].particles

    trackNo = 0
    trackPoint = 0
    curves = []
    splines = []

    for p in particles:
        if trackPoint == 0:
            # Create new track
            curve = bpy.data.curves.new('particlePath', type='CURVE')
            curve.dimensions = '3D'
            curve.resolution_u = curveResolution
            curve.bevel_depth = bevelDepth
            spline = curve.splines.new('NURBS')
            curves.append(curve)
            splines.append(spline)

            #set first point
            print(spline.points[0])
            print(spline.points[0].co)
            spline.points[0].co = (p.location[0], p.location[1], p.location[2],1)
        else:
            # Add point
            splines[trackNo].points.add()
            splines[trackNo].points[trackPoint].co = (p.location[0], p.location[1], p.location[2],1)

        trackNo += 1

        if trackNo >= tracks:
            trackNo = 0
            trackPoint += 1

    # deselect all
    for curve in curves:
        curveObject = bpy.data.objects.new('particlePath', curve)
        bpy.context.scene.objects.link(curveObject)
        #...select it?

particles_to_path('Trace',particleSystem=0, curveResolution=8)

The code defines a function (particles_to_path) which will use the particles emitted by a particle system on an object to create a Curve object. Note the last line in the script which invokes the function, specifying the object 'Trace'. This will use the first particle system on the 'Trace' object and will create a Curve. To invoke the function on multiple particle systems, simply duplicate the last line and change each as appropriate.

For example, for multiple objects named 'Trace', 'Trace.001', 'Trace.002', 'Trace.003', etc. use the following lines :

particles_to_path('Trace',particleSystem=0, curveResolution=8)
particles_to_path('Trace.001',particleSystem=0, curveResolution=8)
particles_to_path('Trace.002',particleSystem=0, curveResolution=8)
particles_to_path('Trace.003',particleSystem=0, curveResolution=8)

If you have multiple particle systems on the same object, each emitting from a single vertex then you can use the 'particleSystem' parameter to indicate which particle system to use (0 = the first one, 1 = the second one, 2 = the third one, etc.) :

particles_to_path('myMesh',particleSystem=0, curveResolution=8)
particles_to_path('myMesh',particleSystem=1, curveResolution=8)
particles_to_path('myMesh',particleSystem=2, curveResolution=8)
particles_to_path('myMesh',particleSystem=3, curveResolution=8)
particles_to_path('myMesh',particleSystem=4, curveResolution=8)

Once you have generated the curves, simply adjust the curve properties to generate the required trails. For example, set Resolution and Fill in the Shape settings to generate a curved shape...

...and use the Geometry Bevel settings to adjust the 'trail' - setting Start and End to position it along the curve :

Note that the Taper Object can be used to specify an additional curve object which defines the shape of the bevel along the curve (with Map Taper enabled to taper the bevel along the Start-End interval rather than the whole curve).

Carefully keyframing the Start and End will allow the trail to be animating. Ensure to set the Interpolation of the animation curves to Linear so it matches the motion of the particle emitting mesh.

For the material, you can use a combination of Emission and Scatter on the Volume. This will allow the trails to be partially opaque while still emitting light. Mixing in a Transparent shader based on the light path allows them to be hidden from all but the camera (so they don't reflect off of the surfaces). Including variation based on the Random object info provides automatic variation for each trail (you could assign individual materials manually in you prefer more control).

This can produce the following result :

Blend file :

Applying this to the example 'dancer' mesh can produce the following effect :

EDIT: I have since packaged the above script as an add-on as part of this answer, available from here. This makes it much simpler to run and avoids the need to create and edit a custom script.


How do you stretch and then release a soft body or cloth so it springs back like elastic?

Demo of what this does here:

I just had a quick play with this idea and got something pretty close.

Create soft body.
Create armature with two separate bones.
Parent soft body to armature.
Stretch the soft body by moving one of the bones.
This is where it gets a bit limited, but apply the armature modifier as a shape key (I know, you're stuck with the amount of stretch at that point, but trust me, it has some effect and might help).
Keyframe the value of the shape key so that it stetches out slowly over maybe 50 frames, then key it down at 0 about 5 frames later.
Play the animation, and notice how the oscillation of the soft body seems to have been amplified by the quickly retracting shape key.

I really didn't think this would work at all, so having it do at least something made me quite pleased.

See what you can do with that.

I tried keying the deform influence of the bone on and off but that didn't have any effect as far as I could tell.

Nb. I used Automatic Weights. If you don't then there should be a weight painting step between 3 and 4.


Create hair particle system. Add wind pointing down. Add material.


In the linked file there is no right leg bones so it's hard to say what's your problem. Anyway, you can easily fix it:

First give all your left leg bones a ".L" or "_L" suffix.
Then select all the left leg bones, go in the Armature menu and choose Symmetrize.
You now have right leg bones and they work.


Creating a cardboard cut-out OR How do I make my geometry respect my 2d image import?

If you use alpha to give transparency I'm not sure you'll be able to give it thickness properly.
What you need to do is use your image as a background, draw a mesh that will have the exact same shape as your star, extrude, unwrap and give it your image as Image Texture.
Or import the shape as svg, make it a mesh, use X > Limited Dissolve to lighten the topology, and same thing, extrude, unwrap and give it the image as Image Texture. In your case the good news is that you won't need to rework the imported SVG.


How can I go straight to edit mode by choosing selection modes?

I agree with you - and set up a macro on Belkin Nostromos Keypad.   So I kind of cheated to solve this (and set it up outside of Blender).    I also have been playing with this same macro with "VoiceMacro" to do the same thing.   "Vertex" is programmed to: Press ESC (make sure I'm out of circle select),
Press Tab, 6 (edit mode)
Press 1, (vertex select)


Python: how to iterate through and rename shape keys?

What about this?

import bpy

for shapekey in bpy.data.shape_keys:
    # rename / translate shape key names by changing shapekey.name
    for keyblock in shapekey.key_blocks:
        # rename / translate block key names by changing keyblock.name


When rigging the character verticels are flipping (solved)

Actually you have two identical meshes in the same object, go in Edit mode and check out (use L to select a whole mesh), one is correctly rigged (at least it seems) and the other one not. Delete the bad one.


How to drive the normal node with an empty?

I propose a similar setting, but where the normal is driven by a vector defined by the difference between the empty location and the rendered point location (that could be whole sphere location instead).
Here is opposite views when the empty is moving:

Here is the material setup:

The driver is set on the location vector of a mapping (with no input)
From that there is the calculation of the difference between the driven values and the rendered location
The output is normalized and plugged as normal vector

Each driven axis is defined this way, respectively for X, Y and Z:


Blender-Python: Select and iterate vertices after each other from left to rigth, top to bottom

Operator solution
Since you're asking specifically to select a vertex:
import bpy

data = bpy.context.view_layer.objects.active.data

bpy.ops.object.mode_set(mode = 'OBJECT')
verts = sorted([(v.co.z, v.co.x, v.index) for v in data.vertices], reverse=True)
bpy.ops.object.mode_set(mode = 'EDIT')

for z, x, v_index in verts:
    bpy.ops.mesh.select_mode(type="VERT")
    bpy.ops.mesh.select_all(action = 'DESELECT')
    bpy.ops.object.mode_set(mode = 'OBJECT')
    data.vertices[v_index].select = True
    # modify manually here, e.g.:
    # data.vertices[v_index].co.y += x
    bpy.ops.object.mode_set(mode = 'EDIT')
    # use bpy.ops here, e.g.:
    # if x > 0: bpy.ops.mesh.hide()

Bmesh solution
import bpy, bmesh

mesh = bpy.context.edit_object.data
bm = bmesh.from_edit_mesh(mesh)
verts = sorted([(v.co.z, v.co.x, v) for v in bm.verts], reverse=True)
for z, x, v in verts:
    v.co.y = z+x # example

bmesh.update_edit_mesh(mesh)

Changing for different planes (views)
I assumed the Back Orthographic view and XZ plane: . For other planes you need to sort differently. Perhaps remove reverse argument and use minus signs to swap the sign of the coordinate inside the tuple used for sorting. So the following line:
verts = sorted([(v.co.z, v.co.x, v) for v in bm.verts], reverse=True)

would become: [for Back Orthographic]
verts = sorted([(-v.co.z, -v.co.x, v) for v in bm.verts])

and for Front Orthographic you would change the sign of x for sorting:
verts = sorted([(-v.co.z, v.co.x, v) for v in bm.verts])

Likewise you may want to turn (v.co.z, v.co.x, v) to (v.co.x, v.co.z, v) if you rotate the camera by 90 degrees or want to iterate by columns instead of rows.
Interactive Testing
Here's a script allowing to test if the order is correct, by pressing Ctrl+Shift+F12
bl_info = {
    "name": "Vertex iterator",
    "category": "Mesh",
}

import bpy

addon_keymaps = []
current_vertex = 0

class WorkMacro(bpy.types.Operator):
    """Work Macro"""
    bl_idname = "object.work_macro"
    bl_label = "Work Macro"
    bl_options = {"REGISTER"}

    def execute(self, context):
        global current_vertex
        data = bpy.context.view_layer.objects.active.data
        bpy.ops.object.mode_set(mode = 'OBJECT')
        verts = sorted([(-v.co.z, -v.co.x, v.index) for v in data.vertices])
        bpy.ops.object.mode_set(mode = 'EDIT')
        z, x, v_index = verts[current_vertex]
        bpy.ops.mesh.select_mode(type="VERT")
        bpy.ops.mesh.select_all(action = 'DESELECT')
        bpy.ops.object.mode_set(mode = 'OBJECT')
        data.vertices[v_index].select = True
        bpy.ops.object.mode_set(mode = 'EDIT')
        current_vertex = (current_vertex + 1) % len(verts)
        return {'FINISHED'}

def register():
    bpy.utils.register_class(WorkMacro)
    wm = bpy.context.window_manager
    km = wm.keyconfigs.addon.keymaps.new(name='3D View Generic', space_type='VIEW_3D')
    kmi = km.keymap_items.new(WorkMacro.bl_idname, 'F12', 'PRESS', ctrl=True, shift=True)
    addon_keymaps.append(km)

def unregister():
    bpy.utils.unregister_class(WorkMacro)
    wm = bpy.context.window_manager
    for km in addon_keymaps:
        wm.keyconfigs.addon.keymaps.remove(km)
    del addon_keymaps[:]

if __name__ == "__main__":
    register()


Can I Select Through A Face When Using Subsurface Modifier?

I suggest to hide (H) the vertex, edged or faces you don't want to select.


To use image as displacement factor in Displace Modifier, Texture Coordinates have to be set to UV and the mesh properly unwrapped.


Materials not showing in object mode or render view

Your eye is made of two spheres, one with the iris and pupil textures and a second that surrounds the first which I expect you plan to put a transparent texture that also adds the part in front of the iris.

This second sphere has no texture yet, which is why it hides the inner sphere when rendering. Also you have hidden the vertices for this outer sphere in edit mode which allows you to see the inner sphere in edit mode.

Press ⎇ AltH while in edit mode to unhide the vertices, you can then select the outer sphere and assign a transparent texture to finish your eye.


Go in Edit mode, select the 2 hip bones, then the torso bone, then ctrl P > Make Parent > Keep Offset. Now the torso bone is the parent of the 2 hip bones, and the Keep Offset option allows them to keep their position and not stick to their parent.

Also, you need to assign an Inverse Kinematic constraint to your calves, it allows to reverse the influence of the bones so that the legs are not controlled by the base anymore, but by controllers that you will create and assign as Targets.


Why i don't have a bolt mesh in blender?

The bolt object is available from an addon that is included with blender, as it isn't showing up, that would indicate you need to enable the addon.

In File->User Preferences under addons, search for bolt and then enable the bolt factory addon. If you click Save User Settings, it will be enabled every time you start blender.

When you first enable the addon you will find bolt at the bottom of the list but if you save it to always be enabled then you will find it under the default mesh objects.


I was not calling the information properly. It is not under bpy.types.Scene.conf_path but rather C.scene.conf_path.


Your object has a Delta transform (Rotation X = 90°)

Clear rotation in your Delta transforms
Add +90° to your regular X Rotation and press Enter
Done.


How to have an asymmetrical texture on a mirror modifier model?

If I understand correctly what you want, enable the Data > Mirror U and Mirror V of your Mirror modifier:


For a large rippling body of water such as a lake, rather than use a fluid simulation (which would require a great deal of simulation time to get believable results) you can combine multiple waves to give the effect of ripples on the surface of the fluid - similar to that in this answer. However, if you don't need it to be seamless, you can use Wave textures instead of plain Sine waves with the Distortion significantly increased - this will reduce the number of waves you need to combine to get a believable result.

For example, consider the following material :

Here, two Wave textures with high noise are combined via an Add maths node and used to drive the Bump of a flat plane. Note that one of the Wave textures has been rotated via the Mapping node.

The Value node is keyframed to vary the offset of the Wave textures - to move the waves 'forward' as the animation progresses.

By adjusting the rotation, Scale, and other Texture parameters you can get quite a pleasing effect as follows :

Note that this is using the Bump node to generate the Normal. If the water will be viewed from a very shallow angle it may be preferable to add geometry and use True Displacement to create actual waves in the mesh.


Yes, alpha brushes for sculpting require a very dense mesh. Really dense.
Try the default cube with a Multiresolution modifier and at least 8 subdivisions = 393,000 faces.
Better 9 (1.6 million) or even 10 subdivisions (6.3 million faces). Then a sculpted line will look like the brush image.


I agree with "10 Replies": Yes

A vector recreation, saved as high of a resolution png that you need,
can be much better than using just a scan.  (Unless it's a good scan already, but you'll probably want to cut it out, etc...  Still a vector will be noiseless and sharp at any resolution.  An exception is if your decals have gradients or many colors-- if it's more like a photo than line art/ clean sharp shapes.)

As mentioned already too, you can't use vectors directly as a texture in Cycles.  (But you could at least with the old renderer: https://www.blender.org/forum/viewtopic.php?t=12870 )

But I also agree with Duarte's "Don't bother retracing" comment.

Instead, use a tool like Illustrator's Live Trace, Inkscape's Trace Bitmap, or http://vectormagic.com to save a ton of time.  Then you can save your clean, sharp vector as a raster texture to size the you need.  Later, if needed, you can make an even higher resolution png texture for your blender render.

A good clean vector file of vector-like art is always preferred to have, even if you can't use it directly as a texture in Blender.


It seems like your bloom is not enabled at all.

Go into the scene tab and make sure the bloom box is checked.

No bloom:

After checking the bloom box:

If you really have checked the bloom box, try making the threshold much lower or increasing the emission amount and increasing the radius to get it more glowy. If neither of those work, try testing the bloom feature on a plain cube like I did to make sure it works.


See render preview in a second monitor while modelling

Can't you just duplicate the window (Window >>> Duplicate Window) and drag that duplicate over to your second monitor?


As for the reason why it is happening, it is because the main direction of where your HDRI's light is coming from is from the bottom right corner of your image, and the floor is blocking that.

In order to fix that, if you go to the node editor, change the view to world shader and add a mapping and texture coordinate node for your HDRI, you can adjust the tilt of the HDRI.  If you connect the generate output of the Texture Coordinate node to the input of the mapping node and the output of the mapping node to the input of the Environment Texture, then you can control the angle of the HDRI.

You can use the rotation values in the Mapping node to adjust the HDRI's angle.


With cursor positioned as desired and vertices / edges selected scale it while choosing axis which you'd like to affect on scaling (in this case Global X):

Select vertices, set Pivot Point to 3D Cursor.
Press S to scale, then X to scale to 3D Cursor by X axis axis.
Enter amount of effect of scaling. In this case it will be 0.


How does one seamlessly loop an animation containing a Noise modifier?

To loop a noise-based animation
One approach, I can't guarantee it's the snappiest, but it has some advantages.
You could use the NLA editor, to make an action loopable, in much the same way as you would make an image tileable  in an image editing application. For an image, you might split it down the middle, swap left and right halves, and blend across the discontinuities at the center. Same here.
Here's a noise-based animation, 100 frames, which doesn't loop.

In the Graph Editor, take the curves with noise modifiers, and convert them to actual keyframes, by using Header menu  > Key > Sample Keyframes

Switch to a Dopesheet > Action Editor window, and crack open an NLA window below it. An action should automatically have been created, which you can Push Down to the NLA editor, as a working strip.

In the NLA editor, you can ShiftA add a track. Put the cursor halfway down your strip, select it, and Right-Click menu, or Y, split the strip under the cursor.

Now you can select the halves of the strip separately, drag one of them to the spare track, and swap the halves, so the cuts are against the ends of the animation. You will have to shorten the overall length, so there's an overlap between the strips:

To get the automatic mixing in the overlap between the strips you will have to set the Auto Blend in the NLA's N panel:

This example produced a looping 86-frame animation:

.. Which can be baked into an action in its own right by using 3D View > Header > Object > Animation > Bake Action. You can reuse and adjust the loopable noise action with other objects, so long as the same properties are being animated, or even cut and paste the keyframes between channels of different types.


Booleans ussually fails on non-manifold mesh.
To see these problematic parts - from within Edit Mode, using Vertex selection, with no geometry selected, Search for "manifold" (Select non-manifold operation appear). For more info see Blender Manual

Q: Is there a way to 'fill' model and make it completely solid?
A: In a meaning - closed mesh without holes - Yes
_
Fill
Search for Fill operator and increase number of vertices in tool properties until the holes are filled. Like here it was value 14.

But N-gons are not the best for boolean operations so probably better to try ...
Grid Fill
Like here. Important for this function is to have a loop of even number of vertices. If you don't have, you can select one edge and subdivide it.
(White vertex in the screen is one I added.)

Or even better to Triangulate whole mesh Ctrl+T
Remesh
Or you can try Remesh modifier > Sharp if there is too much work, but even on hi Octree Depth in wouldn't be precise.


Model which is called Chainsaw is a group instance. Select this model in Viewport or Outliner and click delete. You can add again this group by Shift+A => Group Instances => Chainsaw.


Where is particle edit radius in Blender 2.8?

In 2.80 the tool settings that you previously found in the toolbar region can be found at the top of the 3D Viewport. As there is limited space only the common options are visible with others in a menu to the right.

You can also find the same options in the properties editor.


How to create an animating Plasma ball in Blender?

Using some modifiers (even if first though was about Animation Nodes):

The base mesh is a tube, larger at the two points connected to the inner and outer spheres. This mesh has its origin at the center of the sphere.
It is also parented to an empty, which is at the center too.
The empty rotation is animated.

This object has several modifiers:

One array which origin is an animated empty, so that we have several instances of this mesh around the center.

A second one with same principle to vary the rotations

.
Then two displacements, one for the main part (the tube), one for the part attached to the outer sphere.
These displacements use another empty as coordinates objects. When this empty is animated, it makes variations in the displacement.

The displacement itself is based on a distorted noise.
Finally, a shrinkwrap to make sure the extremity stays on the sphere surface and a subdivision.


Some vertices are hidden in edit mode (not using H)

This is because you have a Subdivision Surface modifier. They aren't really missing, it is just the surfaces being smoothed over those vertices, hiding them. You can either disable the modifier in edit mode:

Or you can toggle Limit Selection to Visible:

Here is an example:


How to link custom object animation controls to rig components

I've found what looks like a good solution. Still need to test it in animation editing. In case anyone else is attempting to do this, this is what I've setup:

Create a new child bone of the knee bone (thigh bone, not the shin bone) and extrude it outward from the knee. Make sure this bone is "connected" to the parent. Call this bone IKKneePoleArm.L. Then extrude again (from this new bone) and call the second one IKKneePoleHandle.L. Disable Deform for both of these.
Setup normal IK using IKKneePoleHandle.L as the pole target for the leg.
Go into the bone settings and turn off inherit rotations for IKKneePoleArm.L. This will   keep the feedback problem (mostly) at bay.
Completely hide IKKneeHandle.L. You only need to rotate IKKneePoleArm.L around its orbit axis to aim the knee. You can also disable the other axes (in pose mode).
You can also attach a sphere object to the pole arm, so that it appears to be a sphere that orbits the knee. Then you can grab the sphere and push/pull it around and the system will convert that into rotations.

The only issue I've found with this so far is that some adjustments seem to lag behind by one frame by a small fraction. So if you type in values, you have to press enter twice (only if you are cursed as a perfectionist).

If there is a better solution anyone knows of, I'm definitely interested. Thanks!


How to bring Grease Pencil drawings to another .blend file? - 2.80

I was able to do it by copying the GPencil item from the Outliner, and pasting it to the new file.
So now I know this can be done this way.

What sucks is that I was doing this in the hope that the Onion Skinning effect would be restored, but it wasn't. It seems the Onion Skinning effect got affected when I imported an image to draw over.


How can I rename value node animation references in the dope sheet editor?

I don't know how to rename the "Default Value (Value)" labels directly. However, you can put them in a group. Select the references then press Ctrl+G to create a labeled group.

The groups are highlighted green in this image


What is this black line in my rendered donut?

It looks like You are following the tutorial for beginners made by BlenderGuru aka Andrew Price, Hassan, right? If I remember it right he duplicates the top half of the donut and make it bigger and then use proportional falloff to make that random chocolate edge.

Because of duplication of a top half part of a donut there is a big chance of overlapping vertices so to solve this, please select the donut (complete one) and go to EditMode and DEACTIVATE the "Limit selection to visible" (bottom green circle on the image) to make the hidden vertices visible. Once done please select the top vertices with the B key (WITHOUT the middle ones - marked RED) and delete them with the X key choosing VERTICES as shown on the picture - done!

The vertices which needs to be deleted are selected below ... You dont need that top part of a donut anymore cause You have the chocolate object instead now ;). Hope it helps buddy.


How can I make a low poly triangular pendentive?

You can use circle meshes to create the exact shape in your example image, if I understand correctly.

I created circles on three faces of a standard cube, removed doubles, deleted excess vertices, filled the faces, and fixed normals:


(2.79) How do I make a plane transparent without making the texture transparent?

so actually I'm an idiot and forgot to use face textures and alpha face textures
I got it working
whoops


Briefly, unpack how these things look and get the nodes to represent your intention.  You want the dust to accumulate on certain surfaces based on the forces being applied.
That said, seeing the dust in your example, I don't think this is easily achieveable with nodes and you might be better served painting a map or two by hand. The reason is that some of the mechanics in play are hard to express with nodes. For example "I want dust to accumulate on upward facing surfaces, but only on the back of the vehicle where it isn't blown off" is- by itself- at least 2 nodes. Then you have rough surfaces and smooth surfaces that violate that rule, some places where it sticks underneath, and so on.
I'd suggest studying the reference photos and painting a mask or two to help control where the dust appears in general.  Then, from there, use your noise maps and procedural generation to take it to the next level of detail.


I like to use array for such surfaces

Then I will apply Arrays and close boundary using Bridge Edge loops

Next I need a subdivided plane, and I'll add cloth simulation on it. I need to add two vertexes at corners in a new vertex group to use as a pin group, so that the surface will appear like it held by corners.

Finally, I will add a surface deform on the lattice, so that it will follow plane deformations.


How to edit "skin" instead of edit bones?

This could possibly be because their selection has been limited in the outliner. To make sure this isn't the case, check and see if all of the pointer icons in the outliner are white, and not grey. Click them to change if they are.

This could also be if you are in the wrong mode. Armatures have three modes;

 Object mode is portrayed by an orange cube, it allows you to change which object you can select
 Edit mode is portrayed by a grey cube with four orange studs on its front (I suspect this is the one you're in) it only allows you to change the shape of the bones in your armature
 Pose mode is portrayed by a small white man waving his hands around like he's trying to slow down a Taxi, it allows you to wiggle the bones around once they have been shaped right in edit mode.

You need to switch to object mode in order to select the mesh "skin" of your object.


How do I get the position of an object from a previous frame? Not the current frame

Image Above.  Graph View shows an FCurve and its attributes.  Location {X,Y,Z} components.  Each of {X,Y,Z} has a different F-Curve. The Python Console View shows querying the active object for an fcurve by name.  Your object name will appear differently.  Next the curve is evaluated at different points.  Note that {0:X, 1:Y, 2:Z} shows the [conceptual] map between the array index and the concept of axis in the [find] function.  This number is labelled RNA axis in the image above.  Please Click on image to see a larger version for improved readability.

Thus you can

Find the FCurve by name and axis index
Evaluate the FCurve value at a chosen frame.
Use the notion of current frame as an integer value in Python
Calculate Vector V1 at frame (X) and V2 at frame (X+N). X and N may be integers.
Calculate velocity vector (V2-V1)/N

Some quick snippets to help you search further at BSE.  Sorry I can not find a simple example in my personal documents.

object_bq = bpy.data.objects[name]
test = object_bq.animation_data.action if (None != object_bq.animation_data and (None != object_bq.animation_data.action)) else None;
if (test):
 fc =       object_bq.animation_data.action.fcurves.find("Some Curve Name Visible in the FCurves Editor Panel");
fc.evaluate(framenumber)

The above old pseudo code is not claimed to be Pythonic or immediately usable.  You  will need to improve the code.  The code above is intended to establish that the FCurve exist for the provided textual name.


How to apply an image texture on a cylinder

A UV map is a 2D representation of a 3D object.

The name UV map is derived from its axis’. In 3D space, x y and z is used to represent the dimensions of width, depth and height respectively. When we go to a 2D plane, instead of using xy, we use uv as shown below.

If you unfolded a cardboard box and laid it out flat, that is a representation of your cubes surface area.

Blender uses this 2D mesh to allow texturing.  By colouring in the faces of the unwrapped mesh, blender will project that image onto the respective face on your mesh.

If you leave blender to unwrap the mesh itself, stretching can occur. This is when a rectangular face is unwrapped into a square face, or vice versa. This most often occurs when your objects geometry is unbalanced.

To fix this, select your object and go into edit mode. Select everything and press control-u and choose smart uv unwrap. Press ok on the pop up window.

In the image viewer, you should now see your mesh presented in 2D.

If the 2D mesh does not look proportionally correct to your object, you will need to apply the scale.

Blender has two ways of storing it’s dimensional size data. One is the each axis’ length which is the true size and the other is the objects dimensions which is used for accurate scaling and uv mapping. If you scale your mesh on one axis or extrude or extend it in any form, the dimensions change on one axis only.

For example; we have a cube 5x5x5 units and dimensions of 1x1x2. When blender tries to unwrap it, it will stretch any face that had an z direction. So your cube will have four sides twice as long as the others. Try it  in blender to gain a better understanding.

Note how the faces on the UV in the image editor look like they are all in the same proportion and on the object they aren't, stretching the texture

To fix this, go to object mode and select your item. Go to object->apply->scale. Fixed. You may need to go through the uv unwrapping process again.

Here is the quad with correct UV unwrapping:

Quick tip:

If you have multiple objects that require uv unwrapping, do it to one object then select the rest. Set the active object to the object you just UV unwrapped and hit control L. Chose object data.

Tada. Magic.

Good luck with your project and I hope I helped,

BFB


Make sure the Pivot point is set to Median Point (⎈ Ctrl,) or Bounding box center (,) in 3D view > Header:


Adding armature with shift+e, but doesn't mirror in x-axis

Your armature object as some rotations.
In object mode, select the armature and press Ctrl+A / Rotation to apply it.


How to get a plane to intersect and join/merge with the perpendicular plane?

You want to stick this edge to this face but this is not a clean topology because your edge will just float, you should first use the knife tool to cut the roof and the left side, in order to add vertices, then fill with faces between the vertices with some F, and at last delete the inner faces:

Edit with your current file, as we can see you have floating edges, inner faces, etc:

What should happen:


Find the type of a panel displayed in the UI

If Edit Source fails, then it's created by a script on-the-fly (through PyConsole or Text Editor), or it's hardcoded in C - which is more likely the case. You won't find the panel subclasses in bpy.types in the latter case, they aren't exposed to python.

I usually try to find similar panels or even other types via Auto-complete in the PyConsole, to figure out the naming scheme. Take the Grease Pencil panel for instance:

There is no bpy.types.GREASE*, so no header, menu, panel or operator. A different name is used apparantly. We can also check for any type that contains "grease":

>>> [d for d in dir(bpy.types) if "grease" in d.lower()]
['BlendDataGreasePencils', 'CLIP_PT_tools_grease_pencil', 'GreasePencil', 'GreasePencilLayers']

Nothing useful in there, I would now try another part of the name or an abbreviation:

>>> [d for d in dir(bpy.types) if "pencil" in d.lower()]
['BlendDataGreasePencils', 'CLIP_PT_tools_grease_pencil', 'DOPESHEET_MT_gpencil_channel', 'DOPESHEET_MT_gpencil_frame', 'GPENCIL_OT_active_frame_delete', 'GPENCIL_OT_convert', 'GPENCIL_OT_data_add', 'GPENCIL_OT_data_unlink', 'GPENCIL_OT_draw', 'GPENCIL_OT_layer_add', 'GPencilFrame', 'GPencilFrames', 'GPencilLayer', 'GPencilStroke', 'GPencilStrokePoint', 'GPencilStrokePoints', 'GPencilStrokes', 'GreasePencil', 'GreasePencilLayers']

This revealed something useful: The naming scheme. Grease Pencil operators start with GPENCIL.

Time to grep the Blender sources! GPENCIL_PT_ won't match anything, this kind of abstraction isn't really used in the C code. But we know there are buttons (=operators) drawn in the panel, so we can search for them and try to locate what adds them to the layout - GPENCIL_OT_ finds blender\source\blender\editors\gpencil\gpencil_buttons.c among other files.

GPENCIL_OT_data_add is the first match, on line 306 it reads:

    uiTemplateID(col, C, ctx_ptr, "grease_pencil", "GPENCIL_OT_data_add", NULL, "GPENCIL_OT_data_unlink");

This is part of the function draw_gpencil_panel(), this is defintely the right place.

UI widgets are directly added to the layout:

uiItemO(col, IFACE_("New Layer"), ICON_NONE, "GPENCIL_OT_layer_add");

This is obviously the C-equivalent of

col.operator("gpencil.layer_add", text="New Layer")

Some of the functions could probably be ported to python, but others can't. Take the 3D View layers widget for example: it draws nice little orange dots on the layers, which have at least one object on them. We couldn't do this nicely in python.


Transparent shadow not appearing in viewer node

Not sure what you're trying to accomplish here.
Right now your compositing nodes will display nothing because there's nothing fed in the input color. So basically you ask Blender to display "nothing" according to an alpha map.

Besides, I'm pretty sure you want to display this shadow on the floor beneath your model. In which case, what you want to do is either use a material on that flood to display shadows where you want and not use compositing at all.

Something like that:

Compositing is meant to make changes on the rendered picture. May it be color corrections, deformations, ... But it's really on the rendered picture level, not on what will be rendered. Think of it like editing pictures with Photoshop, but using nodes.


Transparent Cube With illuminating Object

The Emission from your "glass" is interfering, among other things. I've found one of the most practical ways to produce "glass" in eevee, is through the node setup below:


1) Duplifaces (or dupliverts)

After creating the object to duplicate (hexagon in this case) and parented it to the armored suit, you should enable in the parent's Duplication panel (in the Object tab) the option Faces.

By enabling the Scale option, the hexagon will be scaled accordly to the face's size, so in the part of the mesh where the quads are more dense, you'll have more dense hexagons too.

Till you don't Make duplicates real, the hexagons will be attacchet to the mesh. This can be really helpful in animating meshes with shape keys, or transfer cloth simulation from the parent to the child without involving all the duplicated geometry.

Note: that you can study the hexagon pattern in a way that can cover the whole suit without leaving spaces, in order to completely replace the base mesh, but a more suitable way to do this is:...

2) Tissue add-on

As stated by the creator:

  Tessellate tool allows the user to copy a selected object (Component) on the faces of the active object (Generator), adapting its bounding box to the shape of quad-faces.

There are a few option that can help you in the modeling, such as automatically vertex merging, proportional Z-scale. I think that is currently the best option to repeat a pattern on a surface while adapting the geometry to the face scale and get an organic look.

I was in hurry and I didn't used hexagons but octagons because the pattern was easier, but I'm sure that with some time you can get the effect you want.

The add on is currently in develop, so it still doesn't support shape keys, uv,... but they are working on.

Here's the blender artist thread about it.

The add-on include also another feature, called "Dual mesh" that:

  ... modify the selected meshes creating dual meshes. Dual Mesh output is a polygonal mesh derived from the triangular mesh. Quadrangolar meshes are automatically converted to triangular before.

Balsically youll'get a pattern of hexagonal N-gons from every mesh, which you can extrude.

Triangulate your mesh, that simply run the command and you'll get:

Than you can extrude individual faces to get an invincible-dragon-scale armor:

Credits:
Armor suite model from blendswap made by simitron


simulated cloth doesnt show through glass in Evee

change material settings
blend mode: opaque
shadow mode: opaque
screen space refraction: no


Camera coverage calculation inside a room

Bisection using frustrum planes.

In the answer to this How to find all objects in the Camera's view with Python? @ideasman42 has written a little method to get the for planes of the camera frustrum.
For a simple room can utilize this to chop away any walls
In gif above the wireframe box roof included is chopped to result and its percentage of originals face area printed to system console.
Script: Run in object mode with room as context and camera of interest the current active scene camera.
The mesh created after chopping and removing mesh outside is added to scene with global coordinates.
EDIT corrected for ortho camera.
import bpy
import bmesh

def camera_as_planes(scene, obj):
    """
    Return planes in world-space which represent the camera view bounds.
    """
    from mathutils.geometry import normal

    camera = obj.data
    # normalize to ignore camera scale
    matrix = obj.matrix_world.normalized()
    frame = [matrix @ v for v in camera.view_frame(scene=scene)]
    origin = matrix.to_translation()

    planes = []
    from mathutils import Vector
    is_persp = (camera.type != 'ORTHO')
    for i in range(4):
        # find the 3rd point to define the planes direction
        if is_persp:
            frame_other = origin
        else:
            frame_other = frame[i] + matrix.col[2].xyz

        n = normal(frame_other, frame[i - 1], frame[i])
        d = -n.dot(frame_other)
        planes.append((n, frame_other, d))

    if not is_persp:
        # add a 5th plane to ignore objects behind the view
        n = normal(frame[0], frame[1], frame[2])
        d = -n.dot(origin)
        planes.append((n, frame[0], d))

    return planes

context = bpy.context
scene = context.scene
dg = context.evaluated_depsgraph_get()
ob = context.object
camera = scene.camera
cloc = camera.matrix_world.translation

bm = bmesh.new()
bm.from_object(ob, dg)

bm.transform(ob.matrix_world)
total_face_area = sum(f.calc_area() for f in bm.faces)
for n, cf, _ in camera_as_planes(scene, scene.camera):
    bmesh.ops.bisect_plane(
            bm,
            geom=bm.verts[:] + bm.edges[:] + bm.faces[:],
            plane_no=-n,
            plane_co=cf,
            clear_outer=True,
            )

face_area = sum(f.calc_area() for f in bm.faces)
# comment out (or delete) 3 lines below for no new object
ob = bpy.data.objects.new("Test", bpy.data.meshes.new("Test"))
bm.to_mesh(ob.data)
context.collection.objects.link(ob)

# print result
print(f"{100 * face_area / total_face_area : 4.2f}%")


This kind of distortion often happens when you modify the mesh that has been unwrapped. You can try to unwrap once again after modification, or pin the vertices of islands you want to stay in the same position and then unwrap. In UV/Image Editor window select all the vertices except the distorted one and press P.

Now select the whole mesh (A) in a 3D View window and unwrap it. Being in UV/Image Editor window unpin all using ALT+P shortcut. The modified vertices should come back to their places.


Welcome to the stack exchange! It sounds like you are having some hiccups with keyframes.
Firstly you're going to want to be able to see your keyframes. Grease Pencil Key frames are not visible in the Timeline so you might want to change the timeline at the bottom to Dope Sheet and then choose Grease Pencil in the adjoining drop down box. You should now be able to see your key frames when you select a Grease Pencil Object.
Why do your drawings delete on a new key frame? Well that's because when you move to a new frame whatever you draw on that keyframe lives on that keyframe only. Blender will show the last keyframe until you add a new one and that's why your previous frame appears to disappear when you add a new drawing. You can copy the previous frame quite easily, either click the draw button in the top left when in Draw mode then Animation, and Duplicate all layer or I tend to go into the new frame and enter edit mode, Select all with A, then click G and hit enter that effectively copies the frame.
In answer to your final question regarding some items appearing in edit mode and not Draw, do you have any modifiers, lattices or armatures at play here? Usually their effect is turned off when in edit mode so that would be my guess although being able to see your keyframes may unearth something else going on.
Hope that helps!
Matt


You need to use solidify modifier.

Here is its effect on a cut torus.
A positive thickness value adds a layer inside the model, while negative value adds to the outside.
Read more at: blender 2.82 Reference Manual


Hair Particle, final Render shows less particles than in the viewport

So i figured it out!!! It happens when the hair dynamics button is checked. I have unchecked it and it works as it should

Is this a bug?


Eeevee Light Path, how to make transparent to camera

Eevee has no real concept of rays. But in order to ease the workflow between Cycles and Eevee some of the outputs are supported in particular cases. This node makes it possible to tweak indirect lighting in the shader.
Only a subset of the outputs is supported and the ray depth has not exactly the same meaning:

Is Camera: Supported.
Is Shadow: Supported.
Is Diffuse: Supported.
Is Glossy: Supported.
Is Singular: Not supported. Same as Is Glossy.
Is Reflection: Not supported. Same as Is Glossy.
Is Transmission: Not supported. Same as Is Glossy.
Ray Length: Not supported. Defaults to 1.0.
Ray Depth: Indicates the current bounce when baking the light cache.
Diffuse Depth: Same as Ray Depth but only when baking diffuse light.
Glossy Depth: Same as Ray Depth but only when baking specular light.
Transparent Depth: Not supported. Defaults to 0.
Transmission Depth: Not supported. Same as Glossy Depth.

See https://docs.blender.org/manual/en/latest/render/eevee/materials/nodes_support.html
In your specific case you could use the compositor with multiple view layers to achieve the same results.


Update a shapekey Basis from another shapekey

Let's say you have 3 shapekeys: Base, new Face, expression.
The first is the old mesh, the second the new modified mesh, the third the old expression movement you want to preserve.
Select the object and the basis mesh, enter edit mode, select all vertices, Ctrl V "Blend from shape": in the toolshelf (T) in the bottom left of the 3D view you will have to choose the "new Face" shape key, and set an amount (Typically 1.0).
Exit edit mode and you should have your expression shape key working on the new face.

Once you understand the principle you will have to tweak the values and the shape keys, maybe propagating not all but only some vertices, setting the amount not to fully 1.0, or tweaking your old expression shape keys, but you will have a good starting point.


Physics sim - Progressively destroy bridge

I've had similar problems in the past, there are just a few simple things you need to do to avoid everything exploding. Just need to set the threshold for activating to be a little higher.
When making the cell fracture make sure that you have a decent margin so that the pieces aren't inside of each other. As well as make sure that the pieces have their origins recalculated to their centers. While the margins might not look good, you can always boolean the original uncracked object out of the way later during the animation.
The most important part is to make sure that after you've made all the rigid bodies, to go to the object menu, rigid bodies, then select connect. This will add a bunch of rigid body constraints that will help keep the bridge from exploding.

Just make sure that you change the setting in the constraints to breakable so that it can actually fall apart when given enough stress. You can also quickly copy the value to all of them by selecting all the constraints with one set as the main active. Then just set the breaking to on and then right click it, a small window should appear, all you have to do is click copy to selected.


How can I add a bone constraint to an armature bone if it only lets me select the individual bones outside of Object mode?

To create a constraint follow these steps:

1) Select a bone in your edit mode; in this way you are working with your armature and not with your main mesh

2) Then switch from Edit mode to Pose mode

When you clicked on Pose mode you'll see your selected bone changing color from orange to blue

3) Now you can select the bone you prefer and create whatever constraints you need. You found all the types of constraints here in the image below


How do I get this mesh ready for sculpting?

I’m not sure and it’s difficult to tell with the matcap on but it appears to me that it might be wrong facing normals. Try going back into Edit Mode, selecting all the mesh and pressing “Ctrl+N” to fix the normals. Happy sculpting.


What are you looking for is called Inverse Kinematics (IK):

In edit mode extrude a new bone from the leg (I called it "Foot On Ground") which will be the target of the IK Chain. Set it to "non deform" (uncheck the relative button in the bone properties panel) and parent it to the chest bone.
In pose mode select the leg bone and assign her an IK constraint.
In the empty boxes select "Armature" (it's the name of your armature) and "Foot On Ground". Set the IK chain lenght to 2.
Now the IK chain, 2 bones long (leg and hip Left) will always "point" to the target bone (Foot on ground).

I suggest you to copy some simple estabilished rigs before building your own, trying to understand the basic concepts. Search for Nathan Vegdahl rigging serie (free on Youtube) for an amazing advanced rigging course, from scratch to humane rigging.


How to fill up space with the new grease pencil tool blender 2.78 (early version)

Press N to show the properties region in the 3DView and expand the Grease Pencil panel to find the colour and opacity settings for the fill.


How can I inspect the links between DataBlocks as a graph?

While there was a feature like that up to 2.49, it was removed in blender 2.50 and has not been replaced.

While it hasn't been updated for a while blender-aid may be an option if it still works.


All software uses virtual memory automatically. Operating systems usually take care of that. When you run out of RAM your storage devices are used. That is called paging. Storage drives are extremely slow compared to RAM so things slow down a lot when this happens. 20-30 seconds is extremely unimaginably fast for a render though. My renders, for example, would take 20 - 30 hours and even more per 4K still image if I rendered them on a single PC. Renders take lots of time. This cannot be solved by an answer on Stack Exchange I am afraid.


FBX import not rendering textures, though look linked properly

3 Fixes : The first would be to enable textured solid , By opening the right tab ( use N )

The second is enable the texture mode , above the solid view. [! You have to have lights in the scene so everything is visible )

third would be using the UV / Image editor

Also , in the texture tab ( next to the materials tab ), make sure you have set UV co - ordinant.


When I import to unity I my model gets divided in many mesh parts. Althought Its only one object/mesh

Unity needs to split up your meshes when a certain vertex count is reached (65535 vertices). By the huge number of splits you got, I'd guess that you have an extremely high vertex count in your scene. Check if you still have subsuf modifiers on your objects and remove them before you export to unity. Could you show a wireframe?

Edit
After seeing your wireframe: it is definetely the vertex count, parts of your mesh are waaay too dense. I dropped in some circles, where the problem is most obvious, but all other parts are too dense as well. Google images for "game topology" to get an ideo how "simple" a mesh should look like, for sufficient performance. All details are usually added via texture and normal-maps. I'd recommend that you use your current model for retology and recreate it with fewer faces. The vast majority of your geometry doesn't conribute to the shape of your model, so you don't need it. Next time, save a version before you aply any modifiers, and in general: be careful with the subsurf. Insteady, add geometry, by hand where it's needed.


Finger bones not moving in line with hand?

To me it looks like your fingzrs are influenced by several bones more than they should be.
Each vertex has an influence vale between zero and one. Bones influencing the same vertex can share the incluence valur, i.e. 0,3 for one and 0,7 for another. The total is always 1.
If a veetex is influenced by several bones and the addotion of the influences is >1, there will be issues.
Go in weight paint mode and make sure nothings wrongly influenced by a bone that shouldn't. Also, you can use the weight normalization tools to help you keep influences ≤1.


I made something on blender and pressed something and now I don’t know how to get back to what I was doing please help!

Sometimes there are situations were it is hard to fix a UI state by hand.
In those extreme cases my favourite way is:

Save current blend-file
Open second blender instance (on OSX via Terminal https://blender.stackexchange.com/a/102862/68710)
click: File>Open
Open your first blend-file but uncheck "Load UI" (on the left panel) before doing so

now you got your first file but with startup-file-ui


How do you achieve a retro 3D style, today?

This is a brilliant question. One of the main things was that back then, everything was in grayspace. There was very little in the way of raytracing, so non-lamped areas, reflected (or absorbed) a particularly dead gray. This is apparent even in the most well produced 3D animation and art of the time.
Because processing power was so low, edges weren't beveled, so they were infinitely sharp--a real reality breaker.
Textures were often applied directly to primitive faces so the scale and vanishing points rarely matched between different textures if applied to planes. This gives a kind of "collage" effect that is, besides the gray cast, a hallmark of 90s 3D art.
Also, lighting was really cold, and because of the gray-ness of the surrounding bodies, everything had a gray cast.
I hope this addresses some of the issues in play, though not all of them, I'm sure.


How can I get rendered animation to video instead of a bunch of pictures

Use the Video Sequence Editor to load your rendered image sequence and compile into a video format. This is the conventional means of creating a video with 3d modeling/animation software because compositing is often required for the final product. It takes very little time to compile a video from an image sequence within Blender and you will still have your higher quality image stills if you need to do editing later.

If you still insist on making video directly from your render (not recommended, as you may find you aren't happy with the settings, or artifacts may appear in the video that you can't weed out), you can do that by changing your render file format (Output panel -> Output section -> File Format drop-down) to one of the 3 options under "Movie". Obviously, this will force you to render everything from scratch.

Video Sequencer Example:

I rendered a couple of image sequences from the NLA Editor overnight and am outputting to video right now. Here is how I did that.

Go to the animation tab and/or select the Video Sequencer panel. Then from the menu (those horizontal white bars), you want to choose Add -> Image/Image Sequence:

A file selection view will open. To make sure you have what you need (you will be surprised how it doesn't work sometimes), Choose the start and end frame in the options to the left, and the channel (that is, the layer) you want those images to be placed in, AND box-select (tap B-key, click-and-drag) the image files you want to be used in sequence.  If you only want a single file, follow these same instructions but make the start and end frame the same.

Once you do that, a strip will appear in the channel you chose in the Video Sequence editor. You can select it, press the G key and move it forward or back in time, or even into other channel positions. If you press the N key, you will see options that allow you to extend or crop the image sequence.

I am duplicating the first strip twice using ctrl-C, ctrl-v, and moving them into position. You do not have to have each strip on a separate channel. The third instance of this strip is needs a copy of the first frame so I added that the same way I imported the first strip, but with start and end frames being frame 0.  The latter sequences were saved to a different directory but I still add that one the same as the first. I copied the last frame for one of those and stretched it out over 8 frames using the context menu (N key).

As you scrub the play head (or press "play" on the Timeline), the video sequencer will tick through the animation and play it at full speed once it is loaded (it may still be crunchy if you are low on memory). Here is a gif of that happening:

I copied all those film strips in all those channels 3 times to make an animation that is about 14 seconds (my framerate is set in the Output panel to be 30 fps). Then I was ready to export to video format.

Exporting to video is done in the rendering panel on the right. I selected the mpeg option under file output with high quality settings, Matroska container, and H.264 video codec (those settings are in the video drop down that opens in the rendering panel once you select a video file format).

I do not show this but you want to check Sequencer under the Post Processing drop-down and make sure you have "Frame Start" and "End" set to the beginning and end frames of your animation sequence. Step size should be 1.

Finally, choose Render -> Animation from the top drop-down menu, and wait. This will compile significantly faster than your images took to render.

You can see the result here:

https://youtu.be/LY7LGA8AMr0


Face behind transparent material not visible

You aren't doing anything wrong, this is an inherent problem with Unity.  You are looking for a "per-surface" shader, but you are finding out that Unity out-of-the-box is "per-object" (i.e. doesn't show itself through transparency).

The answer to this question does an adequate job of summarizing your problem, and potential solutions:

http://answers.unity3d.com/questions/609021/how-to-fix-transparent-rendering-problem.html

There is nothing you can do on Blender's side.

As for the hole at the bottom:  try a "solidfy" modifier on the bottom.  This will make the base have thickness and will give both sides of the base drawable normals for Unity to pick up on.  Fail that, play with how the normals are calculated (Ctrl+n)


Open a UV workspace and..

On the 3D side, select a pentagonal face, and ShiftG Select Similar > Polygon sides
CtrlNumpad + expand the selection to include surrounding Hexagons
Edge Mode, Header Select Menu > Loops > Select Boundary Loops and ..
Right-click, > Mark Seams

With those faces selected, U unwrap. This will unwrap the pentagons and their surrounding hexes to separate, identical islands. If you want them all overlapped, those can be snapped together, or ShiftS to the  cursor.. but I must say, haven't figured out a way to do them all simultaneously.

This leaves a ribbon of hexes between the islands, so I (CtrlI, by inverse) selected them, and U > Reset those.. it all depends what you want.


You have probably activated Proportional Editing. Hitting O should revert the behaviour.


UV texture is stretched out, how to fix?

Found the answer in another thread by Kura.

"Few months late, but in case anyone else needs it: if your UV maps are coming out stretched, try going back into object mode and applying object transforms, then try unwrapping again. Usually, this takes care of the issue when it occurs for me, and is the first thing I try if my UVs are stretching."


I need to be able to walk someone through a 3d model in real time

Walking through real time, with near-render quality, would be possible with eevee rendering engine added with blender 2.8. Depending on your computer, this might be enough.

More viable way would be model everything in blender, export it to a gaming engine - Unity for instance. Unity has a pre-made scrips that will not require you to program, to enable basic walk functionality, however it will take some work to move project between Blender and Unity, depending on how complex it is (screenshot would be helpful for better estimate).

If I was you, I would model the entire scene, including materials while making sure my objects have uvmapping configured. I would then bake all the textures for every object to keep as much information as possible.

After that, I would re-create the scene in Unity by importing objects, applying textures and re-creating materials (materials do not move between modeling software and game engines, they are almost always exclusive to only one software and whenever you move something you have to re-create it). Unity has different material capabilities than blender so it will probably be impossible to make it 100% identical, but with baking (which enables you to save a lot of info as textures - stuff like shadows, ambient occlusion, emission, colours, lotsa stuff) it should be relatively close.

Using game engine has a added benefit of being able to generate the application that client can take home - it can be exe file, phone app (with a bit of work) or even a webapp.

Skillset you'd need would require: Modeling, UVMapping, Baking, basic Unity3d usage.


I tried the following method with some success.  It's tedious and not very precise, but hopefully someone posts a better solution.

In EDIT mode and viewing ring gear along its profile so it appears as a straight line, I slowly rotated it. Whenever I noticed the profile getting 'thicker,' this indicated a 'wobble' where the opposing arcs are not aligned because the circle is slightly skewed along its axis of rotation at that point. I then adjusted the rotation along the perpendicular axis until the profile narrowed or thinned.

These adjustments need to be made in edit mode so they are applied in object mode.


Baking in eevee is currently not possible
You can bake indirect lighting, but not textures. For further reading, I found this pretty interesting community post.
It may eventually get implemented one day.


Ton just updated the following page but he did fail to mention anything about whether money can be made off BGE games.

http://wiki.blender.org/index.php/Doc:2.6/Manual/Game_Engine/Licensing

  Licensing of Blender Games

  Blender and the Blender Game Engine (BGE) is licensed as GNU GPL,
  which means that your games (if they include Blender software) have to
  comply with that license as well. This only applies to the software,
  or the bundle if it has software in it, not to the artwork you make
  with Blender. All your Blender creations are your sole property.

  GNU GPL - also called "Free Software" - is a license that aims at
  keeping the licensed software free, forever. GNU GPL does not allow
  you to add new restrictions or limitations on the software you
  received under that license. That works fine if you want your clients
  or your audience to have the same rights as you have (with Blender).

  For people who prefer to lockup software or to restrict distribution
  or copying of their games, the BGE is not a good choice. The best they
  can achieve is to separate the contents (.blend files with game
  design) from the software (BGE) in their distribution, and license the
  first under own copyrights and keep the latter as GNU GPL. Standalone
  games

  In case you save out your game as a single "Standalone" the .blend
  file gets included in the binary (the BGE player). That requires the
  .blend file to be compatible with the GNU GPL license.

  In this case, you could decide to load and run another .blend file
  game (using the Game Actuator logic brick). That file then is not part
  of the binary, so you can apply any license you wish on it. More info

  More information you can find in the blender.org FAQ:
  http://www.blender.org/support/faq/

  (Disclaimer: the former text on this page was inaccurate and had wrong
  statements in it. The current text has been rewritten by Blender
  Foundation's chairman. If you have questions about GPL, consult the
  Free Software Foundation website fsf.org.


I'm not exactly sure what your asking but you could use a displacement modifier with a texture attached. Then extrude all the vertices out and delete them. If that's what your asking.


How to smooth out different interpolation types

An easier way to roll a ball downhill is to use rigid bodies. This way, the active objects are subject to the scene gravity.

For this, you will want two rigid bodies, one active and one passive. The active one will be the ball, the passive will be slope.
Add rigid body physics to each object in the physics tab:

These are the settings for the ball:

These are the settings for our slope:

A note on the difference between active and passive rigid bodies from the manual

Active
The object is dynamic and is directly controlled by simulation results.
Passive
The object remains static and is directly controlled by animation system, thus does not have Dynamics properties.


character made with multiple objects one armature or different armatures

One way to fix this is to select the object, for example, the arm, and then select the armature. Be sure you take the armature into edit mode and select only the bones you want to have effect on the arm.

Once this is completed, parent the object to the selected bones using Ctrl+P > With automatic weights.

Do this same thing for the rest of the model.

Edit 2: Here is a step-by-step for applying an armature to separate objects.

Step 1: Select the piece you want to be the child of the armature by right clicking on it.

Step 2: Select the armature, also by holding Shift and right clicking on it.

Step 3: In the bottom left of the 3D viewport, switch to pose mode.

Step 4: right click on the bone(s) you want to be the parent of your object.

Step 5: Press Ctr + P, then select "with automatic weights.

that bone is now applied to the object, repeat this method for the rest of the model.


How to rename an object's mesh data with Python?

Maybe you should consider to use interactive python console provided in Blender. With Ctrl+space, it will list all possible candidate complete word in current sentence. It will help you guess the desired command that you want. No need to ask at here and wait.

And the answer: object.data.shape_keys.key_blocks is a list of shape key for object.


How do I scale a letter how it should be?

To deactivate $Z$ you can scale pressing S followed by Shift + Z.
$X$ and $Y$ will still scale.
Also the transform panel have little lock icons that you can toggle to lock different properties (like $Z$ scale).


masking a video to show underlying still

I was using mix nodes to join the 2 layers. I order to do this you should use an Alpha Over node. My thanks to CGCookie for their posting on YouTube
https://www.youtube.com/watch?v=1eQst8SAVRE&t=3s
it is version 2.8 but did the trick for me. An added bonus was the multiple masking technique they showed.
I can't add a picture at this point as when posting it seems I overwrite the text so I'll comment afterwards with the screenshot.
Many thanks.
Rob.


Use the Link. (Surprising you already used the word in your question!)
This will enable you to import the object and the change in the original file will be reflected.

You might also be interested in the Scenes. This is a link within a single file.


Which animation method to use in blender for later use in Unity?

Unity supports rigged models.

You would need to learn how to parent armatures to your model and adding keyframes. There're many tutorials on this.

Tutorials
Unity tutorial: Using Blender and Rigify


Sverchok: Adding FreeCAD Dependency on Mac

If you using MACOS, than you don't have apt.
Use your mac installer to install libfreecad-python3-0.18 somehow.
or try files from linux:
https://yadi.sk/d/qG5-IPfmqleeYw?w=1
if it will work, please, reply here.


Turns out, you need to edit the alpha and specular values under Z Transparency and turn on the Alpha influence.

Basically, remove the Alpha and Specular values entirely(Set to 0 or -1, can't remember which) under the Z Transparency in the Material Editor. Then, under the Influence tab in the texture editor, add the Alpha channel and then shift it to 0.


As the RGB color space is 3Dimensional I suggest to directly set the object color via Python.

import bge

object = bge.logic.getCurrentController().owner

red = ... # value between 0.0 and 1.0
green = ... # value between 0.0 and 1.0
blue = ... # value between 0.0 and 1.0
alpha = 1.0

object.color = (red, green, blue, alpha)

You can calculate the "mixed" value by calculating the average:

def mean(*numbers):
    return sum(numbers)/len(numbers) if numbers else None

usage:

red = mean(0.3, 0.7)


Uneven particle system fall on a mesh object

To the rotation problem: you can change in the rotation tab the phase, which rotates all particles in the same angle. You can then randomize the phase a bit to get a more realistic result.
To your distribution problem: I cant really give you a solution for that. I recently ran into similiar problems. What i can tell you is, you need a god topology for the particle system, so more or less even size of your faces (maybe use a remesh modifier). I personally fixed my problem with the weight paint and the distribution by starting over with a complete new emitter object...


So I figured this out while writing the question, so I'm just following up with my solutions here.

Solution for telescopic piston:

The solution was mostly like the last attempt in my post/question, but with the sections/segments parented to the bottom bone and figured I could just remove the _Dist bones I had. Think I was just mostly over complicating things in my head.

First I did was make all the cylinders an equal length. Here each chrome cylinder is 0.6m And make a duplicate where I moved every part to it's retracted position, each section here moves down 0.59.

The base/end parts are still made as before, base/end parented to respective _Loc bone with a Damped Track constrained to keep them pointed at each other.
The Mid bones are parented to the Base to inherit rotation.
Mid_01 has a Limit Distance constraint targeting the root/head of Mid_02.
Same with Mid_02 and 03 targeting the next bone.
Distance is of course set at 0.6 m to match the length of the sections.

Now this setup wont work when rigged in its extended position, it's just a bit easier to set things up when it's extended. So It's just to move everything down in edit mode. Also important to make sure none of the objects are parented to the bones when doing this. And moving corresponding bones/objects the same distance so everything still fits nicely together.

Screenshot showing it in edit mode, pose mode and only the mid sections, can become a bit cumbersome to deal with when there are many overlapping bones and objects.

The Piston_End_Loc bone also has two Limit Distance constraints to keep it from extending/retracting further than the geometry allows. First one tells it that it can't go further than 3.9 m away from the Base_Loc bone. And the other to keep it from getting closer than 0.95 m

Video of it moving

Now this works nicely, but this extends the the inner cylinder first and drags the rest out after it. Going by this video and some others, it seems it should be the other way around(found this just before I was going to post this..).

This is easily fixable by just clearing the parenting on the objects and flipping/rotating the rig around. Then moving the constraints from the Piston_End_Loc bone over to the Base_Loc bone as they have now flipped places(renaming the bones should probably be done if to keep things making sense).

We then finally have a perfectly fine working telescopic piston.

A bit more advanced synchronized telescopic piston:

For the synchronized version I copied over everything except the mid sections. Base and End bones keep all of their constraints.

First I added the _CpyLoc bone to both Base and End, both parented to their respective bones. And moved the Mid bones to the top of the sections, instead of the middle as I did in the first version. This is because I want the top of the cylinders to always remain between the two _CpyLoc bones.

Previously when I copied location from the Base/End bones you would have to awkwardly tweak the position and size of things for them to fit together.

Here I know that there is 5 sections so I can just set the influence on the second Copy Location constraint to 0.2, 0.4, 0.6 and 0.8. I've subtracted a tiny bit to accommodate the bevel/edge of the cylinder.

Video of it here.

And a video of all three variations

Hope someone finds this useful, and that this somehow makes sense.

Here is my Blender file containing all different versions.


AN - How to create path for moving an object or an outline?

Thanks for posting this question.  The animation you found is very cool, and a fun practice project with animation nodes.

I made this mockup with just two circles, but the method can easily be extended to as many circles as desired.  Here are the AN nodes, in detail.

The animation is built around the large central circle centered at point A (0,0), which is a Bezier curve.  Since the circle is a bezier curve, you can use the AN Evaluate Spline node and find any point along the curve.

Using the Timeline Time Info node, animate location B along the curve using the Timeline Info Frame # / 360.  Using Modulo gives just the remainder, so it will repeat after 360 frames.

Using the center point of the circle and the animated point on the perimeter, draw radius line AB.

Use the Object Instancer to create a copy of the circle.  Using Object Transforms Output, rescale the second circle to 1/3 of the original size, and change location to point B.   As before, animate point C along the smaller circle, but this time using Frame/120 since it rotates 3x as fast.  Draw radius line BC as before.

To draw the curve, draw a horizontal line from C to D.  C(x,y) moves with the circles, and D moves vertically only.  D(x) is fixed, D(y) = C(y).

As D moves, it creates the curve E.  A very small plane is set up as a particle emitter, and its location is updated to follow point D.  Over time, emits particles which move to the right at a steady rate of speed.

By joining these particles into a spline using Spline from Points node, then smoothing it a bit, a nice curve emerges.

Here are shows the emitter settings I used.  Note that gravity is set to 0, and the particle velocity has a positive velocity on the Normal, dimension, so it emits directly out of its face, but 0 otherwise.  I've rotated the emitter so that it faces to the right (+X) in the diagram, so it will emit from it's face, in the +X direction.

Here is the .blend file.   It was created in Blender 2.79, using Animation Nodes 2.0.4.  I don't know if it's compatible with the more recent Blender or AN, but I hope you could reproduce this animation if needed.

HTH

-Z


Why are my leaves white when I render, but have the right color in Material view?

It's because in your node setup, you connected Diffuse shader output with Emission shader color input. This is wrong. You can't connect two shaders like that. If you want to control color value of Emission shader with other node, use RGB node for example.


Render shadow on transparent background with Blender Render

On the shadow catcher object, add a material and enable Shadows only in Material > Shadow:

This will make it so that only the shadows cast on the object are shown, the rest of the surface will be invisible, showing the sky behind it.

If you set the alpha to Transparent in Render settings > Shading, the sky will be rendered as image transparency.


Follow these steps to create a clean mesh:

Fix the regions I pointed out. (these faces are currently overlapping)
Select the edges you want to bridge but deselect the edges shown in the image.
Press CTRL+E and select 'bridge edge loops'


Does Blender support a uneven texture Sizes?

You can adjust the Aspect ratio to match the UV 0-1 space.

The UV coordinates have nothing to do with the image and the image will be confined to the 0-1 area. You will need to manually scale the UV coordinates in one axis to get an 1 by 1 pixel ratio on the model.

This is not specific for Blender.


Noob question: How to make objects brighter during design

In Blender 2.79 both Blender Internal (soon to be retired in favor of EEVEE in Blender 2.8) and Cycles renderers give you the opportunity to assign materials which have a color in the viewport in 'Solid' mode.

Select the object and go to the Materials tab in a Properties editor (you have one open underneath you Outliner, on the right of the 3D view)

In Blender Internal, simply assign a material to the object. Its color will show in the viewport.

In Cycles, assign a material, and, in the Viewport panel of the materials tab, give the material the color you would like to be displayed in the viewport in 'Solid' mode ... Switching to 'Material' mode will show you the color of the Cycles material, and can give you more control over the brightness of the viewport representation of the object.


Custom Blender Builds: How do they work together?

In short: until both features are merged into the same build of Blender, you should treat those Blenders as two different applications.

I would suggest to use a file format like Alembic to bridge the different applications you want to use. For example, use the Fracture build of Blender to produce fractured objects, then export those to Alembic. You can then use the Manta Flow build of Blender to import those Alembic files and work with MantaFlow.


How can I stack all faces of an object on top of each other in the UV Image Editor?

In Edit mode select the subdivided plane:

Open the UV Mapping menu and choose the Reset option.
Each quad of the subdivided plane will now be    unwrapped and mapped to the complete UV space. (Each quad will be stacked one above the other).

After resetting the Uv's sometime one ot more of the islands will be incorrectly orientated to fix these :

In the 3D editor, Face select mode, select a face that needs to be corrected. In the UV editor the appropriate island will be displayed, Select this face with the A key then rotate plus or minus 90 or 180°.


You can do this easily with animation nodes in the blender 2.80.

Create a number of instances (with deep copy) and place them using the grid distribution node. Then use the same grid points or vectors to sample the texture with Texture Node, which gives you the color of texture at that point of the grid and by changing the scale of the grid points you can scale the texture mapping as you want.

Use these colors as input color for the vertex of the previously created objects. All the object has material but by using the attribute node in materials you can assign the color to individual objects based on their vertex colors. Here are screenshots of my node tree:


How do you turn on constant interpolation for keyframes in blender?

The settings in the N region only apply to the active keyframe (usually the one selected last).

To change the interpolation for all selected keyframes, press Header > Key > Interpolation Mode in the graph editor header, or press T while hovering over the graph editor.


Mouse click released immediately on drag; can't drag nodes

When I try to move nodes like this, it sometimes releases on its own too, which is pretty annoying. Just click on the node and press G to move it. It never let me down. ;)


So, here is my opinion:

First you need to put the Armature modifier above the Subsurf modifier, and enable the Preserve Volume option.
You should add a little more weight on the butt for the leg, you'll see that it works better when you rotate the leg
Maybe add a hip bone and weight paint to add a little bit more precision in the mesh control?


There are only two add-ons in my mind that I could recommend for making crowd scenes easier to make, but you might know that it can also be achieved using particles.

Crowd Master: http://crowdmaster.org/

MCPrep: https://twitter.com/TheDuckCow/status/1070655223545425920


Armature Deform With Automated Weights only on selected bones

You will find that option in weight paint mode.


How to change from 30fps in the animation view (not render)?

In time remapping, put New to something like 1000.
This will slow down the playback to 3 fps.


What is the differece between Make Library Override and Add Library Override?

According to the manual the operator from the outliner ID Data > Add Library (bpy.ops.outliner.id_operation(type='OVERRIDE_LIBRARY)) is for overriding a single data block.

  Single Data-Block Override

  You can override a single data-block from two places:

  The Outliner (it’s in the context menu of IDs), in which case all local usages of that linked ID will be remapped to the new local override.

  [...]

On the other hand Object > Relation > Make Library Override (bpy.ops.object.make_override_library()) iterates through the hierarchy of objects and collections based on the selection, overriding everything linked.

  Make Library Override Operator

  This one operates in the 3D View, over linked objects or local empties instantiating a linked collection (typically, a linked character). It is very similar to the Make Proxy operator, and is found in the same sub-menu Object ‣ Relations ‣ Make Library Overrides….

  Unlike the method described above, it will go through the whole hierarchy of collections and objects, and override all those needed to allow posing/animation of a character.

  Note

  Proper Collections Layout Matters

  For this operator to work properly, it is crucial that all the collections needed by the character are children of the root (linked and instantiated) one. Otherwise, some won’t be automatically overridden, and manual work will be needed to fix the override.


To correct this you need first a long, non stretched image which will cover the right part of your texture.

Here from left to right :

Left : more or less the problem you have
Middle : with a corrected the UV map
Right : the needed texture with a rusty part all along

The principle is to stretch your UV map part along the texture so that the corresponding parts of the mesh are no more stretched in the 3D view :

The idea beyond that, is to have a proportionality between the mesh shape and the UV shape.

Around this idea, you can setup the different square part of your current UV in several manner :

Overlay them all (as I did in the gif)
Or just take each of them and stretch along V the way you whish

But the starting point is the texture : it needs to cover the surface you want and be proportional to the final result.

When you let Blender unwrap by itself, Blender does keep the proportionality. But sometimes, that guides to have too small part so moving the UV manually is needed.


Highlighting parts of objects throughout animation

While you can animate the material colours as others have suggested you can also composite the change using masks.

Masks can be created in the Movie Editor for existing videos or in the UV/Image Editor if you just want to align a mask to the current render result or image. If your items were moving then you could animate the mask in the Movie Editor to follow the items, you can even parent them to motion tracked points instead of manually positioning each frame.

The bonus with compositing is that if you have already rendered the video or want to adjust an existing video it is much quicker than re-rendering the whole animation.


why does the fog in 3d view look better than in rendered result

The "lines" you see are the dynamic range and the bit depth of the color.
Are you using JPEG  ? or PNG 8 bit ?
Try to render again using PNG 16 bit, or even the industry standard OpenEXR
and using filmic instead of standard helped a lot too,
standard only has 8 bits of dynamic range, while filmic have 24 I believe
output properties > output

This might help to improve your volumetric heavy scene.
try playing with the settings here,  Render - > Volumetrics (eevee)
especially the Volumetric Tile Size , if you set it to 2px, the volume will be very crisp, sharp and looks amazing, but will lag your blender & viewport. Increasing the samples might help too


My world properties node background is missing

You need to use Environment Texture node.
You're currently using Image texture node, which doesn't work right with HDRIs


You can use the Boolean modifier.
First create a cube, then scale it so that it intersects with where you want the door to be.

The hole will be cut where the red line is. Next, click your building and add a boolean modifier. Set it to difference instead of intersect, then set the object to the cube you just created.

Now click apply, and delete the cube used to cut the door. You should end up with something like this:

If you enter into edit mode, the extra faces created should automatically be selected. If you want, you can delete the extra faces and get something like this:

To do what you would want, you could select the vertices around the first doorway, press F to make it a face, then press P and select by selection.

This has created a plane that has the exact dimensions of your door. It is a separate object. Press Tab to go into object mode, click the door plane, and press Tab again, to enter edit mode. Then select everything if it is not already selected, then press E for extrude.

You can then click once it is thick enough, then go back to Object Mode. Move the cube so that it is intersecting with where the door should be projected onto. Then do the same thing I mentioned above with Boolean, only use the cube you created with the door instead of a new cube.

Tada, two identical doorways!


OK, I think I found the solution. In render settings, go to Indirect Lighting and increase the Cubemap Size. Increasing Filter quality also helps.


Strange problem with mesh/normals/normals direction

Try making sure that there are not doubling vertexes,or split vertexes, you can use the merge by distance in the mesh/clean up menu.


How to bind material change to a single animation action?

You can do it using Drivers.

In my case I used a driver to change the intensity of a color.

Hover the cursor over the intensity slider, press RMB and choose the Add Driver option.

Add an Empty and place it at the origin point of a Cube. Parent an Empty with a Cube using Ctrl+P-->Set Parent To-->Object (Keep Transform).

Go to Graph Editor and change the Mode from F-Curve to Drivers.

Change the Drivers Type to Averaged Value.

Input the previously added Empty's name in the Ob/Bone box as pictured below. This Empty will now control the intensity of the Cube's color. If the error appear, click the Update Dependencies button.

Now specify what kind of the Empty's action would have the influence on the Cube's color intensity. I've chosen the Z Rotation, so anytime I change the Z rotation of an Empty, the insity of a color will be changed. The other kind of transformations (like translating or scaling) would not have any influence on color's intensity values.

Add a Generator Modifier and play with the highlighted values to make the transition speed of the color's intesity slower or faster. You can also redefine the initial and end values here.


This sometimes happens when importing rigs from other software.
For the bone shapes, simply select all the bones in pose mode, go in Property Editor → Bone Tab → Viewport Display panel. Hold the ⎇ Alt key while pressing the cross icon to delete the custom object from the entire selection:

Then switch to edit mode, and open the Relations Panel. Still with every bone selected, hold the ⎇ Alt key and check the Connected option. Now all your bones having a parent is forced to stay connected with it. Which means you can't move a bone off his parent, and so the bones' heads are on their parent's tail.


How to use blender 2.8 with a (thinkpad) pointing stick?

On Linux, by default, holding down the middle button and then tilting the TrackPoint generates scrollwheel events.  TrackPoint enthusiasts typically use this to scroll through Web pages/documents.  However, Blender will interpret this as a zoom command.  This behavior can be disabled, but not all desktop environments have a control for it (e.g. Xfce4 doesn't), and the command line incantation is a bit obtuse.
The following was tested on a Debian Sid system; you must have the package xinput installed.  If you have an older version of Linux, the incantation may need to be different, as the support framework has changed in the last two or three years.  First check to see which is your TrackPoint device using xinput list.  You will see output something like this:
⎡ Virtual core pointer                      id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Synaptics TM3072-003                      id=12   [slave  pointer  (2)]
⎜   ↳ TPPS/2 IBM TrackPoint                     id=13   [slave  pointer  (2)]
⎣ Virtual core keyboard                     id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Sleep Button                              id=8    [slave  keyboard (3)]
    ↳ Integrated Camera: Integrated C           id=9    [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=10   [slave  keyboard (3)]
    ↳ ThinkPad Extra Buttons                    id=11   [slave  keyboard (3)]

It's the TrackPoint device whose properties we want to change.  We can specify it either by ID number or, as below, by name:
xinput --set-prop 'TPPS/2 IBM TrackPoint' "libinput Scroll Method Enabled" 0 0 0

This disables button-based scrolling on the TrackPoint.  Holding the middle button down while tilting the TrackPoint will now rotate the view.  Root privileges are not required.  This setting does not persist and must be reset on each login/reboot. To immediately re-enable TrackPoint scrolling use:
xinput --set-prop 'TPPS/2 IBM TrackPoint' "libinput Scroll Method Enabled" 0 0 1

For more information see this Web page, and also man 4 libinput to find out what the arguments mean.


Blender .STL exports are too small when imported in Sli3er

By default, 1 Blender unit = 1 mtr, as evidenced by default gravity value in the scene settings.

You could try setting the scene unit to Centimeters (1 unit = 1cm), then scale accordingly. Make sure to enable "Scene Units" in STL export.

For me, leaving the scene at blender units and for STL export enabling "Scene Units" and setting the scale to 10 works fine. For me. For me, this equates to 1 unit = 1cm


You may retopologize your model and then bake normals from the high poly model to the low poly one. This will save all the details but the geometry won't be as dense, so it will be more animation friendly.

First you have to retopologize your high poly model (take a look at these answers: How to easily make mesh retopology? and How to convert from high poly to low poly).
There are two models pictured below. The high poly one with a very dense geometry on the left and low poly one with a simple retopologized geometry on the right. With your retopologized model you'll be able to bake the details from the high poly model to the low poly one.

Here's how to do it. First unwrap your low poly mesh and create a new texture with the desired parameters.

Next select (with the RMB) the high poly model, then select the low poly one.

Go to Render data header and under Bake panel change the mode to Normals, check the Selected to Active checkbox, then press the Bake button. After Blender finishes baking save the image to your computer.

Now give your low poly model a material, go to Texture header, open your previously saved image and set the settings as pictured below.

To see the normal map in action change the viewport shading type to Rendered and set the GLSL option in the Shading panel of Properties Shelf (N).


How can I change the number of snapping points 'Slide Vertex' uses?

Press G twice to slide a vertex and then press Ctrl+Shift. It will allow you to snap a vertex very precisely.

Also, after pressing G twice, you can move a vertex inputting a value from your numerical keyboard.


It seems the domain object is rendered as a solid, in order to change that you can either disable the rendering of your Domain Object:

or disable some settings for the domain object:


How to lighten or color viewpoint render view?

If you are talking about quick renders background in the viewpoint, it depends on your world settings.

The quick render considering the World setting's parameter as the "background" shading settings. You should be able to change the quick renders background by changing the world's background settings.

  On Cycles :

I'll take cycle's example first. Down below you have Cycle's world settings.
the "Surface" Panel is for the background of the world (which is an Emission shader).

The quick render using this option for background, changing the color of the "Surface" emission shader should do the job.

For example, if I change my "Surface" Emission color to red, my sky / background / environment turns red

  On Internal :

If you work on internal. Then the World setting tab is a bit bigger.
You have the "World" panel for the background's texture, and for your case the "Ambient occlusion" and "Environment lighting" tabs might interest you, to allow the background's light to affect your scene like a sky.

I really invite you to play around with those settings.


As Ethan mentioned in his comment, the immediate suspicion in a case like this is that your World Shader is too bright. If you want the background to be as bright as it is without "washing out your mesh", you can separate the background "look" and the background "lighting" by combining two different backgrounds with a Mix Shader, using the Is Camera Ray output of a Light Path Node as a Mix Factor:


A way to see a mesh in object mode while editing UVs?

If this helps, you can change the color & transparency of that editing mode, adjusting it to let you see what's below.

See in User preferences Themes settings

If it's a temporary change, just don't save user preferences, and it will be reset at next program start, or new file.

Edit:
I'm adding a screenshot of the alternative setup I suggested in the comments:


How to create a gradient material across an object's local z-axis?

Depending on what you’re looking for, you could get away with using Generated coordinates, which are normalized relative to the object’s bounding box:


How can I make a specific part of particles a different color?

You can use Vertex Pain method. Create the material with the color you want, then where you select object/edit mode find vertex paint. Then just pain over the parts of object you want with that color.  Or you can select faces and add that color to them. This tutorial describes the technique: https://www.youtube.com/watch?v=0lj643VmTsg&t=448s

Edit: I am allso new so take it with a grain of sand :)


That's a normal smoothing issue. If you set the default cube to smooth shading, it looks weird as well. That is because the interpolation of the face normals tries to cover 180 degrees over one edge. Starting at -90 on the left the true normals are 0 and to +90 on the other side (relative to the global up axis). That's simply not enough geometry to do that kind of interpolation.
3 solutions:

More geometry, e.g. using a SubSurf modifier (easy, but heavy on the
    polycount)
Manually add edge loops, not a good idea for your
    specific model.
Using edge split.

The cube by default is set to flat shading which splits every edge, so each face has its own normals, no interpolation. Nothing looks too dark, but everything is choppy. Edge Split (for example done by a modifier) lets you decide at what angle there will be a split between two faces, to stop interpolation between them.


Fixing deformation due to IK bone constraint

Without actually seeing the the .blend file. It sounds like a possible issue involving rotation/scale. One should always be sure to apply Rotation & Scale when done. ( Ctrl + A )


What's the name of this tool of Blender?

I think there is no special mode for this. Once you have a background image added to the scene (Shift+A > Image > Background), create your first primitive in Object Mode, then switch to Edit Mode and start modifying and extruding your model based on the background image.


Don't show hidden triangles in Object Mode

You could assign the vertices to a vertex group and then use a mask modifier to hide the vertices.

By adjusting the visibility settings of the modifier you can also use it to hide the vertices in edit mode or only hide them when rendering.


That's perfectly normal. If you're trying to create a material, you should go to the Materials tab in the Properties panel and create a material if you don't have one already:

Then click the "Use Nodes" button:

That should give you a simple diffuse shader in the node editor.


Importing VRML/X3D objects with their original file name

To start added a little script to make accessing the folder easier, we can now set the folder from the UI, Scene properties Scene panel.

import bpy
from bpy.props import StringProperty

bpy.types.Scene.wrl_dir = StringProperty(name="X3D Dir", subtype='DIR_PATH')

def x3d_path_draw(self, context):
    self.layout.prop(context.scene, "wrl_dir")

bpy.types.SCENE_PT_scene.remove(x3d_path_draw)
bpy.types.SCENE_PT_scene.append(x3d_path_draw)

Ok with that done, I can use scene.wrl_dir rather than hard coding the folder.  Here I simply deselect all objects (equiv of bpy.ops.object.select_all(action='DESELECT')) before calling the import op,
then rename the selected objects to the file's name as the newly created objects are selected after the import.

import bpy
import os
context = bpy.context
scene = context.scene

# get list of all files in directory
file_list = sorted(os.listdir(scene.wrl_dir))

# get a list of files ending in 'wrl'
wrl_files = [f for f in file_list if f[-3:].lower() == 'wrl']

# loop through the strings in obj_list and add the files to the scene
for f in wrl_files:
    print("Processing %s" % f)
    # deselect all objs
    for o in context.selected_objects:
        o.select = False
    path_to_file = os.path.join(scene.wrl_dir, f)
    bpy.ops.import_scene.x3d(filepath = path_to_file)
    # rename them to file name, change to basename for instance.
    for o in context.selected_objects:
        o.name = f

Other methods would be to add an empty for each file, name the empty after the file and parent to it.  Or import each to a new scene.