When working with different scenes, lower channels fade out

I found the answer. In the properties tab of the text scene, render, shading, alpha has to be turned to Transparent. I guess there is a bug in version 2.74 that shows the preview in the wrong way.

Tx!!!


How can I get vertex positions from a mesh?

Use the vertex co attribute.

MeshVertex.co

You may want to take the objects transformation into account, in this case you have to multiply it with the objects matrix.

This test script adds an empty at the first vertex location

# Assume we are in object mode and have a mesh object

import bpy
from bpy import context

obj = context.active_object
v = obj.data.vertices[0]

co_final = obj.matrix_world @ v.co

# now we can view the location by applying it to an object
obj_empty = bpy.data.objects.new("Test", None)
context.collection.objects.link(obj_empty)
obj_empty.location = co_final

Another common operation is to get all vertex locations with the objects transform applied, in this case you can use list comprehension to get a list of transformed vertex locations...

coords = [(obj.matrix_world @ v.co) for v in obj.data.vertices]

Edit: updated for v2.80


Go to the action editor. Press Push Down. The action is moved to the NLA editor.

Open the NLA editor. Here you see the Action Strip. You can change it's start and end frame. You can move it around with G. You can add actions strips with ⇧ ShiftA. You can set an action strip to repeat.


What coordinates are chosen by default in Texture nodes?

As Christopher Bennett says in the comments, when you have no texture coordinate attached, it is picking a default for you, that default uses UV coordinates for mapping.
When you use Generated coordinates something interesting is happening.  It's attempting to map the image on the Z axis to your object, and since that axis doesn't exist for your two dimensional image, it's repeating the pixels at the edge of the texture along the Z axis of the object.


Array of 3D circles with same center, and same distance between them, but different radio

It looks as if the intervals along your radii are all the same .. so this is an option:

Order up a mesh circle, sides divisible by 4, fan fill.
CtrlShiftB Bevel the center vertex to desired diameter
Select the radial edges and  CtrlR add edge loops to the desired number.. (right-click out of the operation to leave it without sliding the loops)
Select every other face ring ...
.. and delete.


Pay attention to your tool shelf at the bottom left, you need to ensure that you don't split the verts on import.

As for the position of where the body parts land in space, my guess is that the original units were something other than what Blender is using by default, and that the origin is a shared origin, with the rest of the body parts, so that there relationship is kept.

So if that is important to you, then you probably should not change the origin like I did in the demonstration to simplify the scene with one part.

Instead:

I would recommend scaling your active import down by factors of 10 (eg. 0.1), until it comes into view - once you know how many times you needed to scale to make that happen (eg. if you had to scale down by 0.1 [3 times] then your scale factor would be 0.001), then you can do this for all future imports that were modelled with the same factor.**


You might be able to pull this off using texture coordinate node combined with mapping node, and using project instead of UV. Or you might define your texture as a brush and texture paint it by hand.


Import a bvh file and export it to be the same

I looked a little closer and found a solution. On importing, there's an option to set which axes point up and forward. Set those to Z up and Y forward.

Here's the original file with the axes set like that:

And here's after exporting it and re-importing it with the axes set like that:

As you can see the entire scene gets rotated when you do this, but the files are essentially identical. A possible workaround would be to import with the axes set to their defaults, and when you're done working with it, select everything and rotating it by -90° around the X axis before exporting. Snap the 3D cursor to the world centre (ShiftS > R) and set the pivot point to 3D cursor before rotating.


Blender not allowing different effector collections for two different particles systems

You're using the same particle settings in the two particle systems on your emitters. You have a different name in the particle system slot, but it's not a different setting.
Think of the particle system slot to be more like a material slot. You can put more materials on one object, but as long as the material in one slot is the same as one on a different object, changing one material will change the other, too.
In the materials this is indicated by a small number next to the material's name. The same goes for the particle settings shown below the particle system slots. And like in materials, to get a new independent particle setting, just click on the small number right next to it.


Where can blender splash scenes be downloaded?

The splash for 2.76 comes from the Alike short. I'm not sure exactly what you're looking for, but you can download the splash image itself here. And browse the history of all splashes here. Note that the 2.76 splash was mistakenly labeled as a 2.75 splash, so there appears to be two 2.75 splashes and no 2.76 splash.

As far as I know, the source files for Alike aren't available. However, you can find the sources for more recent splash scenes on the blender cloud.


my huge file size is causing blender to freeze every few seconds

The scene takes up almost 2 GB RAM, if you are indeed using an old laptop, this might be the bottleneck, especially if you have a web browser open with a few tabs, too.
In windows you should always have an eye on the task manager, especially the performance tab.

As Anders, I would not call this low poly aswell, with almost 50k polygons. That is why rob suggested to delete the heads, as they are making up the majority of those. You could however dissolve a lot of edges, too...


While @DuateFarrajotaRamos's answer will seem to work for small angles of rotation, it only approximates rotation and will not achieve 360 degree rotation mentioned in the question. Instead, you can apply a rotation matrix to the actual vectors concerned.

A solution is mentioned as part of this answer https://blender.stackexchange.com/a/77638/29586 - where the X/Z coordinates are rotated based on the Y coordinate using the following nodes :

This works by splitting the Vector into separate X,Y,Z coordinates and applying a rotation using matrix multiplication as :

X = x.cos(angle) + z.sin(angle)
Z = -x.sin(angle) + z.cos(angle)

Varying the Twistiness input will vary the rotation. The Twistiness is measured in Radians rather than degrees so 2*pi radians is a full rotation (360 degrees) - just type '2*pi' into the value node and Blender will automatically calculate.

Note also the Subtract color mix node at the start. This is set to mid-grey (0.5,0.5,0.5) to convert the Generated coordinates ranging from 0.0 to 1.0 into the range -0.5 to 0.5 so that the origin - and centre of rotation - is in the centre of the mesh.

For clarity, here's the complete node setup :

Note that I've removed the 'green' element from the first Subtract MixRGB node. This is to leave the origin of the Y channel at the edge of the mesh so that one end is not affected by the twist (otherwise it twists from the middle). The Subtract and Divide nodes at the end (after the Noise texture) are there simply to increase the contrast of the Noise texture and isn't related to the twisting.

And here's the result :

Blend file attached


Make smooth texture transition animation in BGE

I don't know whether you can fade between two materials, but you could easily set up a mix shader within a single material and animate the factor with keyframes.  So the single material would contain shader setups for your day sky and your night sky, and the mix shader would switch between the two.  It is possible to mix between background shaders FYI (although since you say you have a "skydome" perhaps you are talking about mesh materials, not background materials . . . it's the same principle either way).


The Fill Brush does not do what you are expecting it to do.

The fill brush simply fills the entire image, irregardless of color, back facing, occluded faces or anything else. That is true when used in the UV Image Editor or the 3D view.

There is no way with the fill brush to fill just one color, like can be done with in photoshop's paint bucket tool.

The only way you can limit the fill brush's reach is by masking the faces.

In texture paint mode hit Tab, that will bring you to edit mode.
Select the faces you want to paint.
Press Tab again to go back to texture paint mode. Now press M to turn on the masking feature. (Do note that you can select and unselect faces in texture pain mode when the masking is turned on by  ShiftRMB  on the faces.)
Now when you use the Fill Brush it will only effect the selected faces.


Saving/loading the location(x,y,z) of selected vertices

If Vertex Groups and Shape Keys don't address the problem, it is straight-forward to make a script. I'm not sure I understand your constraints but they seem to be:

locations of verts of the initial object are stored
indices and vert-count are unchanged
coordinates can change.
you want to be able to restore those verts in your modified object which are currently selected.

Rather than writing a script + ui for this, i'd first explore the code needed. I'm going to assume you aren't talking about thousands of vertices, if you do need larger meshes then optimization would help speed up the 'overwrite'

As usual many approaches are possible, i'd start with the one that requires least effort to understand and write. Start a new .blend with a dummy object to represent a simplified version of the objects you are trying to work with in your production files. Get a hang of whether this method works for you or not.

The clone mesh

This makes a mesh clone of your original object, gives it a fake user. The fake user flag tells blender not to delete the Mesh when it has no direct users.

clone.py

import bpy

mode_set = bpy.ops.object.mode_set

ob = bpy.context.active_object
mode_set(mode = 'OBJECT')

clone_mesh = ob.data.copy()
clone_mesh.name = ob.name + '_clone'
clone_mesh.use_fake_user = True

mode_set(mode = 'EDIT')  # place originally active object back to edit

This finds the clone and updates the active_object's selected vertices using the previously cloned mesh data.

restore_from_clone.py

import bpy

meshes = bpy.data.meshes
mode_set = bpy.ops.object.mode_set

ob = bpy.context.active_object
mode_set(mode = 'OBJECT') # updates the list of selected verts too

clone_mesh = meshes.get(ob.name + '_clone')
clone_verts = clone_mesh.vertices

for v in ob.data.vertices:
    if v.select:
        v.co = clone_verts[v.index].co

mode_set(mode = 'EDIT')

Usage without UI:

The top one you run once, at the start. While your base object is active.
The second script is what you run whenever you want to restore the selected vertices.

Ui version

Here's a small UI version of that script. You can either pick a directory using  the selector or paste it in manually. Even if you pick a file from the FileBrowser it will strip the path to just be a Folder/Directory.

It appears in the Misc panel:

if you have the Suzanne Object selected it can clone the object and make a hidden mesh, or look in the directory provided for a Suzanne.json, which it can load as the clone mesh.

clone:  Clones the Object's mesh as a hidden mesh called <object_name>_clone
restore:  Restores the locations of the vertices currently selected
changed:  Selects only those vertices which changed their locations
import:  Tries to import a hidden mesh. The currently selected object's name is used to find the json: directory/<object_name>.json
export:  Makes a <object_name>.json in the directory pointed at.


Select object and recalculate normals via script?

Making normals outside can also be done with the bmesh module operator recalc_face_normals(bm, faces)
Sample script
import bpy
import bmesh

from bpy import context

#bpy.ops.import_scene.obj(filepath=source_to_file)
bm = bmesh.new()
meshes = set(o.data for o in context.selected_objects
            if o.type == 'MESH')
for mesh in meshes:
    bm.from_mesh(mesh)
    bmesh.ops.recalc_face_normals(bm, faces=bm.faces)
    bm.to_mesh(mesh)
    bm.clear()
    mesh.update()

bm.free()
#bpy.ops.export_scene.obj(filepath=target_to_file, use_materials=True)

Saves the need to flip mode and context object.


Got it.

bpy.context.user_preferences.inputs.use_mouse_emulate_3_button = True

It also says on the wiki that The Blender API can modify user preferences, keymaps and themes


How do I scale a skeleton down with out affecting the animation time + the location of the skeleton

When exporting from Blender, calculate the size as 100 percent and export it, eg fbx scale 0.01 or 0.1 This is fixed in ue4.


It looks like only the head is moving and hair object stay where it is. If this is the problem, you can easily fix it in weight paint mode by assigning all the hair vertices to the vertex group, which is controlled by your head bone.


While it isn’t entirely clear in your description, my guess is that your image is a reference image or a background image. These images are used to assist with modeling in the viewport and are not part of the final render.

If this is the case, there are a few ways to put an image in your scene. First, you can put an image on a plane using the import images as planes add on, and position the plane where you want it. Or you can use compositing.

Hope this helps!


how i can texture paint this flat face of my model?

I have had similar problems, It could be that the UV is not "flat", but it does not look like it from the picture. the other experience I had a distortion because the model was too low poly, from the UV editor picture It looks like the face is an N-gon, you could try adding more geometry to it.
As for exporting the UV lines to paint in another software you can Export the UV layout, there is an answer here.


Sorry about the misunderstanding.  I ended up hand matching each portion so that the curves lined up properly.  I was looking for an easier, automated route instead of a manual labor intensive version.


Restricting surface area for snapping to other objects

This is something that I am working on as well, so I might as well share what I have learned.
A nice way to isolate the target area in the edit mode is to hide the geometry you don't want to be affected by an operation.
You can then safely work only on the area you want, without affecting any of the other vertices.
Other notes:
-make sure to toggle proportional editing off; this is an extremely powerful function
-snapping can be used (the magnet icon) to connect edges or align by increments
-use bridge connect tool


How can I add Emission to the "Mortar" of a grid texture?

If you generate your grid texture with a Brick Texture node, you can connect the Fac output to the Emission Strength input of a Principled BSDF:

Note the green glow cast on the small sphere.
If you want a more visible glow/glare around the grid itself, you could try adding some volumetric mist, or you could fake it with Bloom (in Eevee) or using a Glare node in compositing (in Cycles). Here’s an example using Bloom:

(Note that to get the indirect lighting on the sphere to work in Eevee you will need to add Light Probes and bake the lights.)


How to render video to plane/face-of-mesh in evee

Prepare your mesh UV map as for a simple image texture.

Use a material (say 'principled BSDF) and set is color input to 'image texture'.

Choose the video you want from the disk.

In the movie part, set the wanted option (start frame, frames, etc.).

Turn on viewport shading, and play the animation.


Raycast argument Vectors need to be in object's local space.

Ray cast is behaving as expected.  The first parameter is the origin of the ray  src.location and the second is a direction vector, which from a target would be  direction = dst.location - src.location (most commonly normalized)

The vectors also need to be in the local coordinates of the target object being ray-cast onto. Simplest way to calculate another object into target objects local space is multiply the global coord by the target objects matrix world inverted

origin = cb.matrix_world.inverted() * src.matrix_world.translation # use @ for * in 2.8

Test script, using object references as in question.

mw = cb.matrix_world
mwi = mw.inverted()

# src and dst in local space of cb

origin = mwi * src.matrix_world.translation
dest = mwi * dst.matrix_world.translation
direction = (dest - origin).normalized()

hit, loc, norm, face = cb.ray_cast(origin, direction)

if hit:
    print("Hit at ", loc, " (local)")
    bpy.ops.object.empty_add(location = mw * loc)
else:
    print("No HIT")


Is there a way to keep the shadow but turn off the light in EEVEE render

I think the only way to do this is using passes, in the passes menu you can enable the shadow pass and some others, then compositing them together. Do an initial render, enter the Compostiting workspace, and you'll see the different inputs for different values.


You can download the add on "import image as plane"

then you can add a plane image with shift + a:

then you will have to choose your image and it will import it as a plane, turn material below the 3D viewport to see your image:

Another way is to use background image (press N to open the right panel on the 3D viewport) you will see your background image only with the orthographic view (hotkey 5) and front side or top view (depending what your choice on the background image panel):

Here the slider with the 0.1 and 2.4 value are for the lateral an vertical position.


Apply armature changes to mesh so that both the mesh and armature look the same in pose and edit mode

The problem lies in the fact that when you selected all bones of the rig, you didn't select all "Machinary" bones, hidden in others bone layers. Go tot the properties tab, armature, bone layers, turn on every single layer, THEN check if any other bone is hidden (ALT H), then select all and apply pose as rest pose.

In my example picutre a classic Rigify rig, and the same rig with all the machinary bones revealed.

If that doesn't solve the problem, after you have applied your pose as rest pose, select the "bn chest" bone, in the bone constraints panel search for "stretch to" constraint and click the "RESET" button. Do the same with bn neck 01 and bn neck 02.


Controlling or syncing any F-Curve animation speed based on a path's Evaluation Time curve?

Ok, so I made some progress with this, but not exactly the way I wanted to.

I discovered that I can make an animation evaluation curve, similar to the path speed one, if I convert my animation to an Action (simply by switching to the NLA editor view), then selecting my animation strip, then activating the "Animated Strip Time" selection from the properties panel. Now, if you enter edit mode with 'tab' in the NLA and switch to the Graph editor view, an extra curve will be available for controlling Strip time. HOWEVER, there doesn't seem to be a way to control the values with a Driver (since the values are by default, like, keyframed and you can't remove the green and you can't have both keyframes and drivers at the same time on a property). A workaround is simply copying-pasting the Path Evaluation curve into the object animation Strip Time curve.

I will report back if I ever find a better way to do this.


How to change 'pose' of mesh without rigging?

I think that rigging with two bones is the easiest and fastest (adjustable) method to get the job done. Be sure to rig also all the vertices that need to nearly stay in place (they need to be assigned to two bones - one fixed and one moving -: one bone only would lead you to bad elbow joints!)


To remove a material from your file, go to the materials tab and shift+Click the × next to the material.

The material will be set to 0 uses. Consequently, saving your project, closing and reopening it will remove it from the list of available materials.


Pyramid that cannot 3d print because its different in Blender / print software

every 3model you want to 3D print should be closed (watertight), so your piramid should have thick walls, and not single layer faces. That would solve your ghost tip problem as well


Radeon RX 570 not rendering correctly using Eevee [Linux (Ubuntu), AMD]

Managed to fix it by manually installing the bundled packages with the term opencl-*_amd64.deb, using dpkg to correctly install their dependencies as needed. This solution from the devtalk may also work and is probably easier, but I didn't try it.


You can use the 2d image as a background looking through a camera set to the pixels you want the final render to be, and then manipulate the 3d objects in relation to the 2d image without affecting the 2d image shading. Once you have the 3d objects set up and textured as you want them to be, and have worked out your lighting, you can render the 3d using transparent film setting (cycles) or transparent instead of Sky render(Blender Internal).

If you want a hand painted look for your 3d, you might try texture painting the 3d objects in blender after unwrapping them and setting up an image texture at a high enough resolution to look consistent with your final photoshop render.The material you use can either be set Shadeless(blender internal) or use an Emission shader(Cycles) to avoid unwanted shadow, as you can paint in your own stylized shading on the objects. You can also paint on a ground plane that has a transparent alpha image texture, and just paint the shadow there if you want.

The possibilities are endless with how you can manipulate 3d and 2d together, so I leave that up to your own opinion and taste to guide you.


Where do i feed to Translucency map and AO map in the shader?

You want to go with a node setup something like this - Use MixRGB to multiply the Ambient Occlusion value with your BaseColor, and use a Mix Shader to combine your Translucenct BSDF with your Principled BSDF.  See image below:

Also, notice the areas I highlighted - these should be set to "non-color" color space. Additionally, to get the transparency to function correctly, you will have to change your Blend Modes to something other than "opaque" in your material properties settings.
Lastly, you can disregard the difference in names in my image textures, I just threw some in as examples to show the setup. Also, pardon my ugly node arrangement, I had to fit it all into one screen for a good sized screenshot.
Cheers.


Can you assign multiple drivers to one bone?

A driver is used to calculate a single value. Only one driver can be assigned to calculate a specific value.

So yes a bone can have several drivers, one for it's x-location, one for it's y-location, one for it's x-rotation and so on.

If you need to use more complex logic to calculate the value, you can define a python function within the driver namespace.

import bpy

def driver_func(val):
    return val * val    # return val squared

# add function to driver_namespace
bpy.app.driver_namespace['driver_func'] = driver_func


Can rtx graphics cards run cycles renders in realtime?

Cycles is not a real-time renderer. It is possible to have very fast Cycles preview that could be called 'real-time' with high end graphics cards or/and extremely simple scenes, however if you need more than a couple of samples and more complex lighting with decent image resolution(that is basically every single case you would want to use Cycles for) you will not get close to 25 or 30 fully rendered frames per second. Cycles is not supposed to be real-time. It is not designed for that. RTX graphics cards can be used to render with Cycles, however at the moment no other technologies are used to do that as with any other graphics cards, so they are just a bit faster than older cards, that's all.


Make sure your subsurface modifier is on. Also, you will have different results if the view-port and render subsurf levels are not the same.


how to have dripping water when object comes out of water

Edit: TLDR: Add another object that emits additional fluid while the object is being lifted out of the liquid.

Duplicate the cube, scale the duplicate up by a teeny bit, and change that into a liquid inflow object.

For the additional inflow object:

Add a solidify modifier with a really small value. If the solidify value is too large, you're going to get an unrealistically thick layer of fluid.
Delete any faces you don't want to have the fluid emitted from, notably faces such as the bottom.
Add keyframes so that the emitter only emits for a few frames while lifting the object out of the water. You'll have to play around with how long/when you want it to do so.


None of my poses save. Every time I pose my characters arms, they reset and go back to a weird form

You have to add keyframes. Drag the line on the bottom to the time you want, then press I on your keyboard. Select the one you need, which is probably rotation. Important: drag timeline before you change the position/rotation and add keyframe.


Using python to scale/resize a selected groups of faces with individual origin

Hi you should move back them into first position.
I answered based on this question

import bpy
import bmesh

context = bpy.context

ob = context.edit_object
me = ob.data
bm = bmesh.from_edit_mesh(me)
scale_factor = 0.5

for face in bm.select_history:
        center = face.calc_center_median()
        for v in face.verts:
            v.co = center + scale_factor * (v.co - center)

bmesh.update_edit_mesh(me)


How to add a LightProbe to the scene without using bpy.ops.object.lightprobe_add()?

You are on the right track

Check your version. The code below adds a lightprobe to the scene as expected.

Using python console

>>> D.lightprobes.new(
new()
BlendDataProbes.new(name, type)
Add a new probe to the main database

See the options for type by deliberately getting it wrong (Or consult the docs) Note somewhere between 2.80 and 2.83  type has been added to the BlendDataProbes.new(...)(current, currently 2.81) BlendDataProbes.new(...)(master currently 2.83) method.

>>> D.lightprobes.new("Some Name", 'SOMETYPE')
Traceback (most recent call last):
  File "<blender_console>", line 1, in <module>
TypeError: BlendDataProbes.new(): error with argument 2, "type" -  enum "SOMETYPE" not found in ('CUBE', 'PLANAR', 'GRID')

Add a cube probe, link to a new object, link object to collection

>>> lp = D.lightprobes.new("LP", 'CUBE')
>>> foo = D.objects.new("Foo", lp)
>>> C.collection.objects.link(foo)
>>> foo
bpy.data.objects['Foo']

>>> foo.type
'LIGHT_PROBE'

>>> foo.data.type
'CUBEMAP'

>>> bpy.app.version
(2, 83, 1)


Way to use large textures in Blender without crashing?

Unfortunately we are limited by the amount of RAM our computers have. A 21600x21600 image (at 8 bits per pixel and with RGB channels) takes up around 1.3 GB of RAM. Combined with geometry and other programs, this may be more than your GPU can handle.

How I understand it, the GPU, which has it's own set of RAM, is used to draw the blender interface and all the models - but the CPU is used to render the image (unless you specify to use GPU rendering) which uses your main system RAM. So it may be possible to setup the scene without actually trying to view the image in Blender, then render it (possibly from the command line) to ensure the image never loads into the GPU RAM.

However, this might not be enough.
A common method of zooming into something and seeing a high res texture in the animation is to use a bunch of layers:

This is an exaggerated example of course, but the parts of the image you won't ever see in high-detail don't need to be high-res. Cutting up the final image and lowering its resolution for each layer, cropping the high-res ones to show only what you need, will save a lot of memory.

To hide the seam better, use more layers with less of a change in resolution, or create an alpha mask to fade out each layer on the edges.


Volume Absorption makes my water completely black?

Usually the default value of 1.0 on volume nodes is way too high.
Use a much lower value for the density. This is the volume absorption set at 0.001


Blender 2.79: Model Looks Disfigured When Using Viewport Render

The clipping start was set to 0.1, causing some parts to be clipped. All I had to do was set it to a larger value


Why can I pose my rigify model in Weight Paint mode, but not in Pose mode?

The issue seems to be the boolean modifier, which cuts your mesh with the nail mesh. when you disable the visibility of that modifier, the armature deforms the mesh as normal. I'm not 100% sure why this happens, if it is an issue due to laggy update because the boolean takes too long, or if the boolean (more likely) messes up your vertex groups, and thus the weights. It's also interesting that weight paint ignores the boolean apparently.


How to organize an extensible and reusable object?

Alt+d (Duplicate Linked) might be what you are looking for.  By duplicating this way, when you edit one of the instances then all the others will be changed as well.


Layers are now called "Collections". You can find them in the right sidebar.

Here you can find more informations: https://docs.blender.org/manual/en/latest/scene_layout/collections/collections.html


How can I use several computers to speed up rendering?

You can use Netrender  for that.

It's a bit tricky to set it up and get it working.I managed to get it working at one point, but not lately.

Another option is to open the blend file on each computer and render it with the same settings, BUT with fewer passes and different seeds. You can then manually merge the layers in an image editor.


Add-On Dev: Open external file with default program

You can add a wiki URL ("wiki_url") to the bl_info of your add-on. This will result in a link to the documentation in the add-on preferences. Alternatively you can use bpy.ops.wm.url_open(url="") in your code to open the browser.


How do I change UV coordinates while the game engine is running?

After another search session, I found the answer here:

For a working blendfile, see the Blenderartists thread, thanks to HG1

from bge import logic # get the controller that executes the script
cont = logic.getCurrentController() # get the object that uses the controller
own = cont.owner

speed_x = 0.002 # speed by which the coordinates are moved
speed_y = 0.0   # speed by which the coordinates are moved
mesh = own.meshes[0] # access the mesh of the object in question
v_array = mesh.getVertexArrayLength(0) # how many verts are there?
for v in range(0,v_array): # go through the uv's of every vert
    vert = mesh.getVertex(0,v)
    uv = vert.getUV()
    uv[0] += speed_x # change the uv coordinates. uv[0] = x, uv[1] = y
    uv[1] += speed_y
    vert.setUV(uv) # get the game engine to notice the change!!

The name of your script belongs into the controller.


How to use Rigid Body Physics after following path constraint?

Leave the Dynamic enabled, and keyframe Animated instead, on the same frames as you keyframe the Follow Path constraint. Keyframe it to on at the last frame where the constraint influence is 1.0 and to off on the frame after, where the influence is set to 0.0. Hover the mouse on the checkbox and press I to keyframe it.

I changed the Shape setting in the Rigid Body Collisions on the plane from Convex Hull to Mesh, but that isn't strictly necessary if you're ok with the buckler bouncing a little above the plane.

To bake the physics, go to the Scene window and click Bake or Bake All Dynamics in the Rigid Body Cache panel. And if you're only going to render 120 frames, as set in the blend file, you may as well change the end frame for the physics too. No use baking frames you're not going to render anyway.

Here's a short animated gif. I apologise for the quality. I used Blender's built-in screencast, and apparently it wasn't able to keep up with the speed at which the buckler was moving.


Why do I get the error "Camera not Multi-View Camera"?

When using the "Stereo 3D" mode; there only needs to be one camera present in the scene. The left and right cameras are created as children of the active camera, and their settings are controlled from the "Properties Window" -> "Object Data" tab; in the "Stereoscopy" panel.

Using "Multi-View" each camera needs to be added and positioned manually, however there can be more than two. The "Properties Window" -> "Object Data" tab "Stereoscopy" panel is not added in this mode.

The "Properties Window" -> "Render Layers" tab, "Views" panel contains a list of camera "render views", with left and right already preset.
For each of these render views there is an associated "Suffix" text field.
In "Stereo 3D" mode this suffix field simply appends this text to the filename of the render of each camera.
In "Multi-View" mode this suffix field not only appends the text as above, it also identifies each camera producing a render view, therefore each camera needs to be renamed and should end with the matching suffix (case sensitive).

The error; Camera "Camera_XXX" is not a multi-view camera, seems to occur when the name of the active camera does not end with one of the suffixes defined in the "render views" list, or if the any of the "render views" list suffixes are not assigned to a camera.
(This error message seems to return the name of the active camera, and not necessarily the name of a camera that is not assigned to a "render view".)


How long should the Blender BMW demo file take to render?

It depends on your hardware. The BMW "blenchmark" should take however long it takes to render without you modifying the file.
The idea of such benchmark is for folks to see how their particular hardware compares to other in similar circumstances, with the same scene with the exact same settings.
The results are here:
http://blenchmark.com/gpu-benchmarks

Are there ways to speed it up? yes, but that is not the point of said file.
If everybody modifies the file, then there will be way too many variables and the statistics and comparisons for rendering are no longer valid.


Ctrl+Tab will toggle pose mode if an object of type 'ARMATURE' is selected, or it will toggle weight paint if an object of type 'MESH' is selected.

Otherwise, you can select the armature in your 3D View (or outliner), then select pose mode from the menu in the header.


Video Editing Workflow: Use a separate scene for VSE?

Let me explain you a workflow for video editing based on my experience. As every aspect of 3d, everybody has their methods, but the following has worked pretty well for me after trying out a lot of different workflows.

(First of all do not "render" (from actually 3d scenes) from the VSE,  unless you are doing animatics, layout or something that are not final renders)

Start off by rendering your three scenes into single image sequences
without any compositing and organized into separate folders (OpenEXR
is a recommended format).
Do the compositing using your image sequences and render (again) into single image sequences.
Then, using a new blender scene, render the sequences into single movie files.
In your case you should have three movie files to do the final
editing in a blender file used only for editing.

Render image sequences > Compositing image sequences > Movie files > Editing has given me great results. Using image sequences lets you fixed any problems in the renders without rendering the whole thing again, and editing with movie files will let you have a waaay faster playback and editing.

Now, be careful with resolution, FPS and other settings. Every new scene that you use will overwrite the settings. So you have to be very organized in that matter. I recommend you to establish some settings before working on your project. Preferably all your scenes must have the same resolution, or you'll have some weirdly scaled result.


I was able to do this by creating a single edge in the middle (if you don't need to create a loop like I do here with Ctrl + R then you can just select top and bottom edge and subdivide), dissolve neighboring edges to have an angle and do Ctrl + B to bevel.


Objects don't follow the particles system/vertex group

This may be because of a thing where in blender 2.80 and up, auto cache refreshing got scrambled. First it refreshed when it shouldn't've, now it has sometimes not been refreshing when it should've: You probably need to refresh the particle cache manually.
One way that seems fairly solid is change some fundamental setting to the particles/simulation, then immediately change it back. Number of particles is one, particle size is not.
This is just a guess, I hope it helps.


You can bake animation in Blender 2.8!

You'll need access to the Object pill menu. The easiest way to get to this is by clicking on the Animation workspace tab. Then, inside the right layout panel it opens click Object -> Animation -> Bake Action

There you will have access to all the required settings for baking.

Note: If you are animating poses, you can also get to the menu from the equivalent Pose pill menu. Pose -> Animation -> Bake Action

On the menu it pulls up, you can also choose whether you'd like to bake poses, or object data.


How can I achieve box projection with blend for procedural 2D textures using only nodes and without using UV map?

"Blend" is a 0-1 range value, with 0 corresponding to nearly no blend and 1 corresponding to a pretty loose blend.
Not appropriate for anything feeding displacement, as normal depends on displacement; if you need box mapped displacement, bake a UV mapped texture.
Can't really make out your nodes to see how similar that is to what you have.


Use a Dilate/Erode node on the alpha channel in the compositor

with background the node setup would be something like this:


How to know if the model can smile or talk

Ideally, the lips need to be not fused together for a face rig to work properly on the mouth. Otherwise, you'll need to separate the mesh yourself, which can be a pain. Most commercial rigs will not have this problem. Also, if the mouth, teeth, and eyes are not separate objects, they'll be very easy to separate if they have their own vertex groups. Failing that, you can select and isolate by material in the Edit menu. If these things are not stipulated in the details for the figure you're downloading, then you may need to ask the creator specifically.


I was able to fix the issue by changing the bake to non-color :)


Okay, so there are two main kinds of curves in Blender. Bézier and NURBS. A path is a NURBS curve and you want to convert a bezier curve to it. To do this is really easy:

Click on the bezier curve in question.
Press Tab
Select the bezier curve by pressing A
Press Space and search for "Set Spline Type"
Click "NURBS"

Now you have a "path" or NURBS curve to work with. I found this solution in reverse on here.

As for the practical difference between the two, as far as i can tell, the NURBS curve is more accurate and precise than its bezier counterpart. I hope this helps.


How to make something pass behind an actor and be not visible. (Just the part behind the actor)

This is a job for compositing rather than the 3D view. Send the footage into the compositor, use a Chroma Key node to filter out the green screen (you might need better lightning), and then use Alpha Over to place the footage over the render output.


Booleans are a volume-based operation

Literally, boolean is about doing simple maths between two volumes. Like A + B or A - B.
A plane has zero volume. So you're asking Blender to do the maths A - 0... Which equals A.

If you want to remove the end of the nose, extrude your plane so it contains all the parts you want to cut off:

The modifier must be set on the target final object

Your goal is to have your elephant without its nose, so it's the elephant object that should wear the boolean modifier:


The only other "light" source in blender is the Ambient Occlusion. Its not real light but purely a rendering trick that tends to look nice because generally in real-world surfaces that are close together (like small cracks) will be darker than surfaces that do not have anything in front of them, because of shadows, dirt, etc.

You can disable it in the World Properties under the tab Ambient Occlusion.


Animation Nodes - Replicate an object on an already replicated object

Use a "Get Length" node to create the same amount of icosphereinstances as there are splines.

Create a Loop subprogram to loop through the spline list.

we can now use a replicate spline node to get info for each of the splines and position the icospheres accordingly.

Use the spline and object lists as iterator inputs and connect them to the evaluate spline and an object transform output node.

invoke the subprogram.

You can use the parameter of the evaluate spline node to offset the icosphere along the splines.


I UV unwrapped my mesh, but the image texture doesn't show in my object

UV unwrapping just deals with the coordinates for the mapping of a texture it does not assign the image to the material automagically.

In order to have an image be part of the material, you need to edit the material add an image texture node and connect the color output to the color input socket of the shader, then the UV coordinates as vector for the mapping.


Why is the underlying command of "select all" not working when executed with python? (Grease Pencil)

To do with API methods
As commented, the code used looks like it "should" work. Have answered showing a low level alternative to move the gp data points.
Move all points of all strokes of all frames of all layers of the gp object's data.
Narrow down using active frame or layer if required.
import bpy
from mathutils import Vector
from bpy import context

ob = context.object

gp = ob.data
active_layer = gp.layers.active
active_frame = active_layer.active_frame
for layer in gp.layers:
    for frame in layer.frames:
        for stroke in frame.strokes:
            for p in stroke.points:
                p.co += Vector((0.5, 0, 0))

Selecting via operator appears to need 3D view area for context.
Can select all the gp data via operator, by overriding the context to include the 3D view area, eg
import bpy

# assume is in EDIT mode
for a in bpy.context.screen.areas:
    if a.type == 'VIEW_3D':

        # select all vertices (doesn't work)
        bpy.ops.gpencil.select_all(action="SELECT")
        # run in 3d area or override context to "pretend" in 3d area works.
        bpy.ops.gpencil.select_all({"area" : a}, action="SELECT")
        break

However the transform translate operator, on attempts so far,  always returns cancelled. Any attempt to override causes death to blender.


When enabling dynamic topology you have to understand few options for the begginig. (As seen on image)

First option "Detail size" controls how much poligons are created when sculpting for example when "Relative detail" is selected the less the detail size is set the more polygons it will create (more detail), but if "Constant detail" is selected then the higher the detail size is it will have more polygons created (more detail).

"Refine Method" controls how geometry is handled "Subdivide Collapse" will at the same time create and destroy polygons while other options there such as "Collapse Edges" are only going to destroy geometry (destroy as reduce number of it) and "Subdivide Egdes" is going to only keep adding new geometry and that can make your PC freeze.

And finally "Detailing" this is what made your model look like it is only destroying default option "Relative detail" works like this the closer you are to your model the more detail you will have - more polygons created, but the more you are away of the model the less detail you have - and since you are using either subdivided sphere or cube it already has some polygons it looks like it is only destroying them. You can change this option to "Constant detail" and it will work the same no matter how far away or how close are you to the object.


Shadows and lights appear in Viewport but not in Render

I found the problem with the sun's clipping, this might help you and others who have the same issue.
what I did:

Check scale
Check sun's shadow distance.
Look out for troublesome geometries this might have overscaled objects, micro objects, particles systems, hair, emitters, empty meshes, etcetera. normally you import objects from other softwares, in my case as an example I was using trees from forest pack, entities were there but empty, that caused my issue, I deleted them and it fixed the problem.

I hope this works.
now here is your problem:  you have this huge mesh outside the room :)
also you had a hidden geometry (the door's window), you have to delete it or desable it on render.


Is there any way to animate sprites using just the logic bricks in the Blender Game Engine?

Since nobody seems to answer i'll try.

There are built-in ways to animate sprites from a spritesheet
using the texture properties. Unfortunately this feature is broken in some versions.

There is a python script that can do it.

A rather uncommon way that worked well for me is to put each
frame of your animation on a separate plane(square mesh) and trigger a loop
in "edit object-->change mesh"-actuator with numeric property counter.


you can achieve something like that with drivers.
-add a driver on the Y value of your track object.
-open the graph editor and add a Transform Channel driver type like in pic below.
-select the object in "Ob/bone" field that you want to copy the scale value from, I used the default cube's Z Scale channel.
now scaling the cube will spin your Track.
(I don't know how to prevent the scaling of the cube.)

Here is a blend file, I hope this helps.


Do you have any modifiers active? If so try applying them to see if that helps!


Mechanical Simulations With Real-Time Physics

Blender is very effective in representing physical simulations, it has many options and virtually total control of Bullet.

But I've never seen that these "representations" can
extract physical data on the forces involved in each simulation. Blender has no options for that, to my knowledge, I hope to be wrong.


export of multiple animated objects multiplies animations by objects count

Ok so apparently it is impossible to have multiple objects in the same FBX or DAE. I've seen demos that are cheating by merging all objects into an unique armature (so it's an illusion of multiple objects).

The solution I've taken is to have a root bone for each object at 0 0 0 (independant of the next ones) then a bone that's offseting object at right place in the scene. then copy-paste each armature/object in a new blend file. And a checking file that links all scenes of each object (I'm not enthusiast to merge all in a single gigantic armature, because animation in/out/loops are forced to be at same length, it gives no possiblity of independant looping, and no possiblity of re-use independant objects / animations).

It's the best solution I've found. If you have a better workflow for working with multiple animated objects that needs to be synced in a precise timing (like an object jumping onto another when the second one has finished it's apparition), that needs to be exported/readable/triggerable in FBX or DAE, don't hesitate to talk about it.


How to make curve apply its bevel radius after all deformations

Try increasing resolution under bevel in curve data->geometry.


For some odd reason the texture coordinates for your voxel texture are undefined:

Printing the value of the setting with python says that it's set to global, which is not the value you want anyway. Try setting it to generated.

For some reason I also needed to set the viewport maximum draw type to textured in order to get this to work in 2.72, which is extremely odd..

This was not needed in 2.69. I've reported this as a bug here. It has been fixed as of this commit, which will be in 2.73.

Also be sure to allow the voxel texture to influence the scattering color of the smoke, otherwise it will not be colored like you might expect:


Script for export vertex in CSV dont work

Given that the error appears at opening the file, I strongly suspect that your outputFile is malformed:

Check that the path exists, the filename doesn't point to a directory, spaces in directory names are handled correctly etc.

You can paste the lines in the console one by one, the python interpreter will give you a verbose error message

Check these answers here

Where does console output go

Python script fail, look in the console for now


Weird changes in object mode after editing in edit mode

If you still wish to repair the model, here is how:
Tab into edit mode and select the head key under object data (The Upside down Triangle with vertices).
Hide all the other keys if they are not already.
Your object should look normal, now toggle on and off the legs key and select the affected vertices.
Once they are all selected, delete them. (X > Vertices)
Hide every key except basis and select it. Now rebuild the faces. This is fairly easy with edge select and press  F.
Double check your weight painting and your all good.


Why does python need you to define a properties's existence?

Although I think this is more a Python specific question, maybe an answer is still useful for style.

It is possible to use the all keyword

import bge
from bge import logic

def property(cont):
    own = cont.owner

    speed = own.get('Speed')
    level = own.get('Recoil_Level')
    size = own.get('Proportion_Size')

    if not all([speed, level, size]):
        print('No properties found in Weapon_Recoil_Level_Determiner')
        return

    own['Recoil_Level'] = speed / size
    print("recoil level: ", own['Recoil_Level'])

cont = logic.getCurrentController()
property(cont)

.get() is useful because it will return None if the key isn't present.


Which cycles rendering pass is antialiased

You need to know, that there is nonstandard algorithm to get anti-aliasing in cycles instead normal render. Each pass in cycles also is an anti-aliasing pass too. Each pass specifies the color, shadow and antialiasing at same time:

And cycles has a setting to manipulate how far each pixel sample can deviate to get anti-aliasing:

Making the filter size value smaller will squeeze the samples more into the center. So there is no option to turn off anti-aliasing, but you can make filter size at minimum to get similar result:


As far as I understood, low poly modelling means that you model your meshes using a very low number of polygons (not that you optimize your high poly model).
In this video you can see the workflow, it's very simple and fun:
https://www.youtube.com/watch?v=YALV3HqfdLY
Basically this is the process:

start with a basic shape, go to edit mode and edit it
you can extrude, inset, bevel, loop cut, knife..
proportional editing is also useful sometimes
looptools' relax could be also a nice tool to learn
color (with a simple palette)
done!


I suggest using the image options in the UV Editor to better unwrap your mesh first. Try the Color Grid to see how the image flows on your mesh object first before trying to go to Substance Painter to make the texture paint, as Substance won't correct a bad UV Unwrap. Look into unwrapping each part separately using 'Follow Active Quads' to get a better alignment and flow on the mesh.


Subtracting an object and then deleting the object used to subtract within python script

Can add modifiers with obj.modifiers.new(name, type).  When a primitive is added it is the context object.  Changing the order made the large_cube context object, otherwise it can be set with context.scene.objects.active = large_cube.

import bpy

context = bpy.context

#Small Cube
bpy.ops.mesh.primitive_cube_add(radius=1, location=(0, -1.5, 0))
small_cube = context.object

#Large Cube
bpy.ops.mesh.primitive_cube_add(radius=2, location=(0, 0, 0))
large_cube = context.object

mod = large_cube.modifiers.new("Boolean", type='BOOLEAN')
mod.operation = 'DIFFERENCE'
mod.object = small_cube

# large cube has context.
bpy.ops.object.modifier_apply(apply_as='DATA', modifier=mod.name)

context.scene.objects.unlink(small_cube)
bpy.data.objects.remove(small_cube)


Edge Selection - Selection highlights vertices only?

Looking at your image, you are in vertex selection mode, that doesn't explain why the edge in between the two selected vertices isn't highlighted, so most probably you have doubles. Select all by pressing A once or twice, then  W  and choose remove doubles, watch the status bar at the header of Blender to see how many vertices are removed, this should work normally, you can set selection by edges instead of vertices by pressing Ctrl +  Tab  then choose Edge.


When setting up the image source specify a capsize.

e.g.:

source.capsize = [50, 50]

Based on your code:

BGE 2.50+

setup

import bge

controller = bge.logic.getCurrentController()
owner = controller.owner

cameraName = owner['cam']
materialName = owner['material']

scene = bge.logic.getCurrentScene()
camera = scene.cameras[cameraName]

materialId = bge.texture.materialID(owner, "MA" + materialName)

renderToTexture = bge.texture.Texture(owner, materialId)
owner["RenderToTexture"] = renderToTexture

source = bge.texture.ImageRender(scene, camera)
source.capsize = [50, 50]
renderToTexture.source = source

refresh

import bge

controller = bge.logic.getCurrentController()
controller.owner["RenderToTexture"].refresh(True)

BGE 2.49

setup

import GameLogic
import VideoTexture

controller = GameLogic.getCurrentController()
owner = controller.owner

cameraName = owner['cam']
materialName = owner['material']

scene = GameLogic.getCurrentScene()
camera = scene.cameras["OB" + cameraName]

materialId = VideoTexture.materialID(owner, "MA" + materialName)

renderToTexture = VideoTexture.Texture(owner, materialId)
owner["RenderToTexture"] = renderToTexture

source = VideoTexture.ImageRender(scene, camera)
source.capsize = [50, 50]
renderToTexture.source = source

refresh

import GameLogic

controller = GameLogic.getCurrentController()
controller.owner["RenderToTexture"].refresh(True)


Perhaps you want a Track To constraint on the lamp targeting the object with To=-Z and Up=Y (although any up != Z would be good.)


Drivers breaking down after model transformation

Bad choice of WORLD space.
To test Added a simple driver #frame - 1 to the drive shaft to get it spinning.
As suspected the issues are caused by a
i) Using rotation transform driver type, with WORLD_SPACE

Parented the whole set up to an empty, rotating the world space of the parent changes the world space of the children and causes irregular results.
Recommend either. Lesser
Change all to local space.  Here is a script to select all parts and will change transform  type driver targets to local space.
import bpy
context = bpy.context

for ob in context.selected_objects:
    if not ob.animation_data:
        continue
    for d in ob.animation_data.drivers:
        for v in d.driver.variables:
            if v.type == 'TRANSFORMS':
                for t in v.targets:
                    t.transform_space = 'LOCAL_SPACE'

After which

Note The outer gear is driven by the stationary  hidden object, No idea why it worked at all.
However as mentioned in comments Eulers are prone to gimbal lock and since it's local could simply use the property.  (Also makes sure the rotation is not restricted to (-180. 180) which can be the case in constraints and can be difficult to diagnose if not aware)
Finally, would contend that all gears could be driven directly by the rotation of the drive shaft. For most cases a custom property "drive" could be added to the gear and the driver could be
self["ratio"] * drive

where drive is a single property variable pointing to the shaft Y rotation, or in the case shown (enable Use Self in the driver)
self["ratio"} * (frame - 1)

since I set that as the drive shaft Y rotation.


Python: Apply object operator to dupli objects

This uses selected_editable_objects, You can find out which attributes are used by passing in a Python context, and then check the terminal for where each requested attribute is printed.

(Yes, we know this isnt an ideal way to design the API, however this is internal C code which defines which context variables are used).

import bpy
from bpy import context

# flat or smooth
flat = True

# use a 'set' to avoid duplicates, can convert into a list after.
selected_editable_objects = set()

for obj in context.scene.objects:
    if obj.dupli_type == 'GROUP':
        group = obj.dupli_group
        if group:
            for dob in obj.dupli_group.objects:
                selected_editable_objects.add(dob)

context_py = context.copy()

context_py["selected_editable_objects"] = list(selected_editable_objects)

if flat:
    bpy.ops.object.shade_flat(context_py)
else:
    bpy.ops.object.shade_smooth(context_py)

Note: this would be more efficient to de-duplicate based on the object data, since its possible many objects reference the same data. But for the example above, its simpler to just take unique objects.


How do you copy and paste keyframes from one Rig to another?

Link the Animation Data.

Select object without the keyframes first.
Select the object with the keyframes to be copied second by holding shift and left clicking.
Press ctrl+L
Select "Animation Data"

This has in effect, copied the animation data from the second object to the first. Note that you must change the current frame of the animation for the cache to update, change to take effect!

This method works for rigs as long as the names of the bones are the same! Please note that the same animation data may not affect two different rigs the same way, if they are not identical in bone rotation, location, and scaling.

(Also, please note that this may not work for complex objects or movements, like armatures or movement that effects individual vertices, unless they are identical. Blender will do it's best, but on objects or armatures with different geometries, it does not know which vertices to effect unless the movement is simple directional and rotational movement applied to the object as a whole. Your best method would be to map the data with a modifier.)


Why do objects move around separately even after parenting?

Make sure proportional editing (hotkey O) is turned off.


How to increase frequency of a repetive animated movement?

Found a possible solution myself.
Steps to perform:

Animate one motion manually. This motion will be repeated and speed
up in later steps.
For the NLA strip created that way set the count of repeats in the
N-key panel.
In the timeline set the start and end to the first frame and to the
last frame of the NLA-strip including all repetition.
Deselect all strips in the NLA editor.
Only Select the NLA strip in question.
Now bake the animation. I choose "object" to be baked. This can take
quite some time.
The result is an additional strip, which includes the complete
animation as it had been animated by hand frame by frame.
Now it is possible to animate the flow of time of this newly created
strip easily.
Disable the the original strip (the one with the repetition modifier
set). You can use this as an backup for later modifications.
Play the animation.

This is one possible solution, which leads to what I wanted. I am sure, there will be other options to fine tune the result and especially speed up the baking time.


Here is a test script.  All strips on channel 1 are selected, sorted by frame_start,  then added to channels 2, 3, 4 etc.  and extended to the frame_final_end of each to the frame_final_end of the last strip.

import bpy

context = bpy.context
scene = context.scene
se = scene.sequence_editor

strips = [s for s in se.sequences_all if s.channel == 1]
strips.sort(key=lambda x:x.frame_start)
print(strips)
end_point_of_last_clip = strips[-1].frame_final_end
for i, s in enumerate(strips):
    s.channel += i
    s.frame_final_end = end_point_of_last_clip


It is a special version of Helvetica. You can check the below links:

https://blenderartists.org/forum/showthread.php?67062-Official-Blender-font

https://blenderartists.org/forum/showthread.php?114438-Blender-s-Font

https://blenderartists.org/forum/showthread.php?90755-Blender-Font


Tryed to install mb-lab- master to blender user preference error message invalid syntax

That version has been coded for Blender 2.80 Beta.

You want this version for Blender 2.79 - https://drive.google.com/open?id=1Wxly5xEYQwPvCvo1Gn95r7iPk02PTWD-


How to merge different coloured materials into single material?

This might serve as a kick-off. If the multiple  materials are simple enough, you could bake the diffuse color component of those materials into a vertex-color layer of your meshes, and then access those colors through an Attribute node in your universal material.

This script writes the various materials' diffuse colors into a vertex-color layer named 'dif_color' of all selected mesh-objects, as far as I've tested it, in 2.79:

import bpy

def lin2srgb(rgb_color):
    rgba=[0,0,0,1]
    a = 0.055
    for c, x in enumerate(rgb_color):
        if x <= 0.0031308:
            rgba[c] =  x * 12.92
        else:
            rgba[c] = (1 + a) * pow(x, 1 / 2.4) - a
    return rgba

context = bpy.context
layer_name = 'dif_color'

for obj in context.selected_objects:
    if obj.type == 'MESH':
        me = obj.data
        if not layer_name in me.vertex_colors:
            me.vertex_colors.new(name=layer_name)
        dif_layer =  me.vertex_colors[layer_name]

        for poly in me.polygons:
            slot = obj.material_slots[poly.material_index]
            mat = slot.material
            if mat is not None:
                # convert from  RGB to sRGB,A..
                sRGB_col = lin2srgb(mat.diffuse_color)
                for loop_idx in poly.loop_indices:
                    dif_layer.data[loop_idx].color = sRGB_col

Cut and paste this into a text-block, select the objects with multiple materials, and run the script.

Then you could extend this node tree, (which picks up the diffuse colors from the vertex color layer through the Attribute node) to do anything else you like with other attributes of your merged material.

If you've got a ton of stuff to deal with, it would be more economical to make a dictionary of materials > sRGB colors first. to avoid the calculation in the loop.. but this is just a one-shot, so that shouldn't matter too much.

I fully expect corrections to come from people who know better than me..


Use the options in the armature modifier: "Display modifier in edit mode" and "Adjust edit cage to the modifier result".

In complement, concerned bones are generally the one used for nearly connected vertices, you can see them in the properties panel:


I checked your file and the culprit is weight paint. The bones are fine for basics but for good control some constraints and extra control bones should be made.

It is hard to advise about weight paint. That is quite specific to every shape and desired deformations. It is something best learned through training or experience and observing already weighted meshes (for example from open Blender movies).

Instead I am going to give steps to rig a face with Rigify addon, which makes things easier:

Insert a new armature, delete the bone. From Armature properties add the pitchipoy.super_face face template.

Align the face template to the face mesh (scale it to size in edit-mode, not with armature scale). The bones should sit on the surface. Turn on X symmetry while editing so both sides are the same.
From pose or object modes generate the final rig from the template. You can delete the template armature, it has no purpose now:

Bind your mesh to the generated rig with automatic vertex weights. The rig has enough control bones so it should turn out fine. If there are some issues these can be fixed by refining the vertex weights further.
You should now have nice controls and a rig menu with layers in tool shelf.


How to apply a texture during an animation?

You can animate the 'Fac' property of a 'MixRGB' node to switch between two different textures, one not burnt and one burnt:

Connect your unburnt texture to the top input of a 'MixRGB' node (Shift+A Colour> MixRGB).
Connect your burnt texture to the bottom input.
Go to the frame just before where you want the burn to appear.
Set the 'Fac' value of the 'MixRGB' node to '0'.
Press I when your cursor is over the 'Fac' value of the node to insert a keyframe.
Go to the next frame, change the 'Fac' value to '1' and insert another keyframe.

For a smoother fade between the textures simply insert the second keyframe a few frames after the first, the more frames, the slower the fade between the two textures.


Can I animate a mesh using raw vertex coordinates per frame?

I would suggest writing to an Alembic file. Blender has nice support for it, and it's a quite compact file format that's fast to read. It also supports things like changes in mesh topology, vertex colours, and point clouds.


This is not something I am focused on but I would just watch / read some tutorials on Grease Pencil, especially these lessons should be useful for you:
https://vimeo.com/channels/greasepenciltuts

Also read the Blender's documentation on this topic:
https://www.blender.org/manual/interface/grease_pencil/introduction.html


How to keep the vertex normals after deleting an edge/face?

A single vertex can't have a normal vector. A normal is the vector which is perpendicular to two other vectors (edges) the normal is calculated using the cross product.

A vertex normal is the average of all surfaces normals which contain a certain vertex, this does not mean that a vertex can have a normal.

Perhaps you could move the original quads to another (invisible) layer.


After some trial and error in the Compositing tab I figured out thatdisconnecting the movie clip from the render layer removed that clip, obviously, but the background then turned white, after which I connected both the Composite and Viewer Alpha channels to the Render Layer, after which the background dissapeared, just like I wanted.

So after rendering with the above node setup my result was just a white mesh without textures or any surface an a transparent background because the render window was somehow overlaying the fore and background. I then tried some other Node conection variations, until I ended up with this one:

This one got me the result I wanted, the mesh, alone and with a transparent background. I don't know what exactly happened, but this seems to do the job for me.


How are particle emitters affected by objects behind?

The problem is caused by the transparent material of the blue 'Cylinder'.
You can fix this by going to its material and then under the Transparency tab and setting your transparency method from 'Z Transparency' to 'Raytrace'.
This should fix your problem!


Snap to closest vertext in object mode goes to bounding box

There are settings in the snap dropdown as shown, make sure you have them set to what you want to snap to


Can´t bake larger textures than 1000x1000px

Did you set the image texture in your material node setup to the new larger image file?

I did bake a cube to a 3k by 3k texture without problem.


How to make texture repeat in X but clamp in Y?

1. General solution (doesn't work in your case)
For many purposes, you can just change the texture repeat settings on the image texture node.

2. More complex solution (works perfectly in this case)
For more complex cases like yours, however, you this can be done quite easily with a mapping node:

Set the min value of, e.g., the y-axis to be whatever works best for your image. The setting 0.4 seems to work well for my simple testing setup shown below.


How to add the same texture to every face individually

Either uv map individual parts to tiles within your texture or create several materials, select your faces and then click the "assign" button under the objects material list.

Uv mapping :

or

Assign :


Hair Particle system and Fluid Simulation interaction

tl,dr
You can't, the fluid simulation system is not meant to interact with non-fluid object/forces/particles.
Keep in mind, that software such as Houdini is free for the apprentice version and allows to export geometry to Blender (as an obj sequence e.g.).

This answer assumes you are a proficient Blender user, given the complex context of the question. Adress unclear things in the comments and I'll extend the answer.
The Manual Way
Manually scatter force field in your scene. Such as Wind. Rotate them manually and keyframe their strength to mimic the flow of the water. Force fields influence hair particles.
This will probably be the fastest way in Blender internally.
The Hack

Keeping the Fluid Domain setting "Generate Speed Vector" box checked opens up a Hack.
The wrong movements in the demo gif arent limitations, but I didn't want to pursue the matter further. (My obstacle needed different geometry.)
Create the Vector Pass for the render layer. Then place an orthogonal camera directly above your scene. We will output the speed of the surface into an image sequence with the following compositing nodes. Don't forget to choose (e.g.) OpenEXR as to not loose negative or higher values.

Choose a small output Dimension (10x15 in my case) and render it.

LTR: image sequence of speed vectors; orthographic camera directly from above, left-lower corner matches (0, 0); render settings
With this method we only get the speed vectors for the surface, so it still won't come close to mimic a realistic result.
Now, we will grab the direction values of each pixel, and place a wind force field at the corresponding 3d position.
First, create some Wind Force fields, since my image is 15x10 pixels, I need 150 forcefields.
import bpy

w, h = 15, 10

for x in range(0, w):
    for y in range(0, h):
        bpy.ops.object.effector_add(type='WIND')
        pass

fields = []
for ob in bpy.data.objects:
    if ob.name[:5] == "Field":
        fields.append(ob)

i = 0
for x in range(0, w):
    for y in range(0, h):
        fields[i].name = str(x).zfill(4) + "_" + str(y).zfill(4)
        fields[i].location = (x, y, 0)
        i += 1

I saved my motion images to "//motion####.exr". Sadly, image sequences don't update on frame change from python, so we will have to load each image separately. Create a new image "motion_image", then execute the code. The comments should make the functionality clear.
import bpy
import mathutils

# method for reading a pixels values
# an image (as in bpy.data.images) has the attribute pixels, a list of values
# in pixels, rgba values come after each other (they are not grouped)
# rows aren't grouped either, they come after each other
# [0x0_r, 0x0_g, 0x0_b, 0x0_a, 0x1_r, 0x1_b ... 15x10_a]
# more info here: http://blenderscripting.blogspot.de/2012/08/adjusting-image-pixels-internally-in.html
def getPixel(pixels, x, y, width):
    idx = (x + y * width) * 4
    return pixels[idx], pixels[idx + 1], pixels[idx + 2], pixels[idx + 3]

scn = bpy.data.scenes['Scene']

# grab our prepared image and its dimensions
img = bpy.data.images['motion_image']
width, height = img.size[0], img.size[1]

for frame in range(scn.frame_start, scn.frame_end):
    # this may take a while, so here the update in the console
    print(frame)

    # load the image from disk into our Blender image
    img.filepath = "//motion/" + str(frame).zfill(4) + ".exr"
    bpy.context.scene.frame_set(frame)
    bpy.context.scene.update()
    img.reload()
    img.update()

    # see CoDEmanX's comment: https://blenderartists.org/forum/archive/index.php/t-268545.html
    pixels = list(img.pixels[:])

    # loop through all pixels
    for x in range(0, width):
        for y in range(0, height):
            r, g, b, a = getPixel(img.pixels, x, y, width)

            # access the wind force fields through our naming system
            ob = bpy.data.objects[str(x).zfill(4) + "_" + str(y).zfill(4)]

            v = mathutils.Vector((r, g, b))

            # convert the direction to a quaternion_rotation and calculate the strength
            ob.rotation_quaternion = v.normalized().to_track_quat('Z', 'X')
            ob.field.strength = v.magnitude * 200
            ob.keyframe_insert('rotation_quaternion')
            ob.field.keyframe_insert('strength')

Don't forget to set all forcefield object to quaternion rotations. ⎇ Alt LMB on a property to change it for all selected objects.
I also offseted my forcefield (0.5, 0.5) to center them in the pixels.

Now we have lots of crazy forcefields which we can use for further experimentation.


Use a hook modifier on the control point. Fortunately there is a easy helper operator for that.
Select the control point, CTRL + H > New Object, then go back into object mode, select the empty, add a "Shrinkwrap" constraint and select the target object.


How to copy the full data path of a property to the clipboard?

Place the cursor over a property and press CtrlShiftAltC to copy the full RNA data path of that property to the clipboard eg. bpy.data.objects["Cube"].location[2].
The hotkey calls bpy.ops.ui.copy_data_path_button(full_path=True) operator:

Somehow related: Add menu entry to generic right-click menu?


Rim lighting in glass sphere? light inside doesnt work?

I think what you are trying to do makes no sense (to me) from a physical point of view (Fresnel equations), so I would use a node setup to "fake it".

The texture you plug into the color input of the emssion should resemble the texture of the emission object inside (I used a noise texture for demonstration purposes).


Missing brushes for Texture painting in 2.8

The tool has changed a bit, and things are now in a different place.

Simply, this in 2.79:

has become this is 2.8:


As You could see on the picture below, the Scatter Color value (green circle) is the point of your interest. Changing this values leads to different cloud scatter colour. Please keep in mind that scatter colour settings is reversed so if You want a red clouds You have to lower the red value.

(values used on the image: R=0.55, G=0.62, B=0,65)

Hope it helps You, Buddy.


Found what cause the problem thanks to @RobertGützkow :)

I have delete somehow Render layer in Compositing tab, by accident. noe it's working perfectly ;)


I'm supposing that you parented your hair object to the head object and parented the head to an armature which include a "head" bone, weighted (automatically or manually) to the head vertices of your mesh.

When you move a bone you are moving the vertices of the mesh without affecting the origin of the object. If your hair is another object parented to the object called "head" it will not move as the Head origin is not moving.
To get the right movement you must select all of your hair objects, then Shift Select the Head Bone, then press Ctrl P and choose  "Bone" option.
In this way the bone movement will affect the head vertices and the hair origins in the same way.


How can you join objects without merging vertex groups? (2.79b)

You need to give them different names. If you have two objects with the same vertex group's names they will merge into one vertex group. If you have objects with different vertex group's names they will stay separated as before.
I hope it helps.


How to bend rigged mesh in wanted direction

I think the issue is that you don't have a pole target. Check out this video for more information:Inverse Kinematics video


Blender Import with materials (textures)

I have downloaded the files you linked to.
I extracted the zip file and (using blender 2.75) used file, import FBX and opened the FBX, hit F12 and no textures.

Closed blender.

Within the zip, there is a .RAR file 'textures.rar'. I extracted that file in the same directory as the FBX and repeated the above process. Textures where showing up when rendering.


Rendering a tracked scene without background

Unchecking Compositing in the Properties editor > Render tab > Post Processing rollout did solve the problem.
Side note: you can go to the compositing nodes in the Node editor (or choose "Compositing" screen layout) and change/remove the Source Movie to remove video from render.


Every point within a UV face describes a point on the mesh face's surface. Every point outside describes a point in the same plane, but outside the face's surface - usually not very useful.

Therefore, a particular UV face should be provided for the interpolation. If the entire UV map contained no overlaps, then any UV coordinate that lies in any of the UV faces will be mappable to a point on the mesh surface, with no ambiguity - in this case, you wouldn't have to specify which UV face to use for the calculation.

But if there are overlaps, then there will be multiple solutions (different XYZ coordinates for every overlapping UV face at the specified UV coordinate).

Every point outside any UV face will not correspond to a point on the mesh surface (but around or inside the mesh). You may want to clamp UV coordinates to [0, 1], so that the given UV coordinate falls within that range again, if texture repetition is desired.

In order to transform the UV coordinate to a 3D space coordinate based on a certain UV face, use barycentric_transform().

Below you find a script that utilized this function.

Note a couple of requirements:

the script expects one Image / UV editor to be visible
a mesh must be selected and in editmode and have a uv map
UV mesh selection sync needs to be enabled in UV editor
2D cursor needs to placed at the location you want to get the 3D coordinate for (in UV editor)
the UV face around the 2D cursor location needs to be selected (this will also select the corresponding mesh face in 3D View because of selection sync)

Then run the script. It should place the 3D cursor at the 3D coordinate. The coordinate stored in "co" is in object space, but turned into world space to place the 3D cursor correctly by multiplying with the object's matrix_world.

import bpy
import bmesh
from mathutils.geometry import barycentric_transform, intersect_point_tri_2d

# this will use the 2D cursor of the first UV editor found
for area in bpy.context.screen.areas:
    if area.type == 'IMAGE_EDITOR':
        space_data = area.spaces.active
        loc = space_data.cursor_location
        norm_coords = space_data.uv_editor.show_normalized_coords
        break
else:
    raise Exception("No UV editor found")

# mesh UVs are always normalized, but not the 2D cursor!
def uv_normalize(tex, uv):
    if tex.image is None:
        x, y = 256, 256
    else:
        x, y = tex.image.size
    return (uv[0] / x, uv[1] / y, 0) # to_3d()

ob = bpy.context.object
assert ob.type == "MESH", "Selected object not a mesh"
me = ob.data
bm = bmesh.new()
bm.from_mesh(me)

# tag selected faces, because triangulate may clear selection state
for f in bm.faces:
    if f.select:
        f.tag = True

# viewport seems to use fixed / clipping instead of beauty
bmesh.ops.triangulate(bm, faces=bm.faces, quad_method=1, ngon_method=1)

# re-select faces
for f in bm.faces:
    if f.tag:
        f.select_set(True)

uv_layer = bm.loops.layers.uv.active
tex = bm.faces.layers.tex.active

def find_coord(loc, face, uvs):
    uv1, uv2, uv3 = uvs
    x, y, z = [v.co for v in face.verts]
    co = barycentric_transform(loc, uv1, uv2, uv3, x, y, z)
    bpy.context.scene.cursor_location = ob.matrix_world * co

random_face = None
sel_faces = [f for f in bm.faces if f.select]
for face in sel_faces:
    uv1, uv2, uv3 = [l[uv_layer].uv.to_3d() for l in face.loops]
    if norm_coords:
        loc_normalized = loc.to_3d()
    else:
        loc_normalized = uv_normalize(face[tex], loc)

    # remember the first face for possible fallback
    if random_face is None:
        random_face = loc_normalized, face, (uv1, uv2, uv3)

    #print("trying", loc_normalized, "vs", uv1, uv2, uv3)
    if intersect_point_tri_2d(loc_normalized, uv1, uv2, uv3):
        print("found intersecting triangle")
        find_coord(loc_normalized, face, (uv1, uv2, uv3))
        break
else:
    print("trying random selected face for extrapolation")
    find_coord(*random_face)

The mesh does not need to be triangulated, but the script may fail especially on non-planar quads (couldn't figure out why exactly).

Due to the triangulation, we do not know which triangle is the best option to use as input for the transformation - we potentially want a point on the mesh surface, and thus we need to chose the triangle the user-defined input point lies within. Otherwise we would extrapolate a coordinate, which is an issue if the target mesh face is a non-planar polygons. We would end up with a coordinate not on the surface in that case, it should still work for planar target polygons however.

To determine that triangle, the script does triangle-point intersection testing for all triangles the triangulation generated from the input face. If the UV-space coordinate the user wants to calculate the 3d coordinate for isn't within the selected UV face, no intersection test will return true. The only option is to abort, or use a random triangle to extrapolate a (possibly unwanted) coordinate - my script does the latter.

The face selection + sync requirement could be lifted by some code to automatically find all intersecting uv faces for the chosen 2D coordinate. You should probably handle overlapping faces, e.g. return one 3D coordinate for every intersecting face.

For some more details, see http://blenderartists.org/forum/showthread.php?379027-Get-3D-location-of-mesh-surface-point-from-UV-Parameter (which was the base for this answer)


Enable the "bool tools" addon, then use its boolean Union function instead of Join. Then you can go with clay strips and smooth brush (better if dynamic topology is on).


with Light selected go to Properties editor > Data Properties > Power add keyframe
go to Graph Editor > View > View Selected (or View All)
if selected add Noise modifier


Is it possible to design a surgical (dental) implant guide in Blender 2.80?

I do not know many things in the dental field, but this should put you on the right track, the answer is yes, you can model what you are looking for, but it is necessary to see exactly what you want to be able to help you improve your model

odc_public
Addon for Blender meant to streamline dental CAD and design workflows

but it is not in 2.8, it is in 2.79 and in addition to this there is another addon especially for the design of dental bridges, as soon as I remember the name I will provide it


the armature has to be "in the mesh".

Here the left mesh and the armature are in a fitting position.
On the right, the mesh copy is offset and so the bone angles are creating distortions.


Why is the ring of vertices not complete?

I think I know what you did. You had a vert or an edge of the line selected and then added the stuff you wanted to hide with box select. The previous selected vert or edge was also still selected.

You could have hit A to deselect it before the box select.

What you just need to do now is press Alt-H to unhide everything (or Mesh -> Show/Hide -> Show hidden), do your selection again and hide it again.


Tracking markers are clustered together and too close to camera

In the orientation panel place a larger distance value and press the apply scale button


So here is a solution with the Mesh Deform modifier:

Create your object.
Create a cube that contains your object as a cage, subdivide it. In the Properties panel > Object > Display, enable Draw All Edges and Maximum Draw Type > Wire so that your cube is in wire mode.
Give your object a Mesh Deform modifier. Put it above the Subdivision Surface modifier. Choose the cube as the Object, and click Bind.
Select the cube. In the Properties panel > Data > Shape Keys, create one Shape Key (it will be called Basis by default), then a second one.
Keep this second Shape Key selected. Go in Edit mode. Sculpt your cube (with Proportional Editing activated) so that it deforms your object the way you want.
Come back in Object mode. Now you can play with the Value of each Shape Key and insert Key Frames so your object is deformed the way you want at the moment you want on the Timeline.


2.81: Where is the "Preferences option allows using the File Browser in full-screen layout."?

It's in the Preferences, first tab.

Preferences->Interface->Temporary windows

And don't forget to save the preferences :).


Is there a way to increase wall thickness after applying solidify?

There is a way in edit mode you might prefer if you select the wall faces and press Ctrl F and choose Solidify. The thickness appears in the operator on the left. The new faces are automatically highlighted so at that point, you can add the new faces to a new group. Then if you make further modifications and want the thickness different you can select the faces from the group, delete and redo.


2.82a - Can't import multiple videos to sequence editor

This has been fixed in 2.83 beta. Grab it here: https://builder.blender.org/download/


Short animated film in Blender in single room environment with several acts - single scene or multiple scene setup?

Just go and keyframe the environment how you want it then delete all keyframes before that point move those keyframes to the first frame and go from there. (this is just a suggestion.)

make sure it's in a copy of the scene btw because you wouldn't want to lose that progress


Blender Render suddenly makes everything black

I managed to solve it thanks to Richard on Blenderartits.org, basically I had to check Shadows under Shading in the Render Tab:


BGE Add object action deforms a sphere mesh

Opening up your file, your PlayerBound object has a scale of 1.28, 1.28, 3.70 on it.

Select PlayerBound, press ctrl+a, then click scale to reset the scale to 1, 1, 1 without changing the geometry.

Right now your spheres are inheriting PlayerBound's scale, making them about 3 times as long as they are wide.


There's multiple ways so let me explain them to you because things like these can really speed up your workflow

You can select any number of vertices (at least 3) and press 'F' to create a face between these vertices.

As you have probably already figured out, quads are the faces you want to go for so ideally you want to select 4 vertices to create a face.

Alternatively you can select two opposing edges to speed things up.

In your example you have like a row of unfilled faces, so you can just select the top edge of the last face before the missing face and press 'F'. Blender recognizes the pattern based on the surrounding faces and fills the next one it. This only works if you have one row of missing faces (in other words: have faces on 3 of 4 sides).

Another technique that's really handy is the grid fill. I think there's no shortcut for this out of the box so just hit F3 to open the search bar and type in "Grid fill". This is especially helpful if you need to connect multiple faces that would result in a grid. An example: a cube that doesn't have a top face and is subdivided 3 times on the sides. Select the edge loop of the top and use grid fill to create top faces based on the subdivions of the sides.

Hope that helps, happy blending!


Whatever material you currently have on your mesh is the default color that object would be.  Something like this:

Go into Edit Mode, and Unwrap your object (I used Smart UV Unwrap):

Open up your image in the UV Image editor, and align your UVs to where you would like.  Little inconsistency I accidentally put in, move the little group of squares outside of the image, this is required for the clipping:

Now go to the texture tab, and set the mapping to UV (from Generated) and select the UV Map you want to use for that image (don't forget to open that image in the texture tab).  I set it to Clip instead of Repeat for the texture mapping:

I set the diffuse color of the material (back in that tab) to be red, so now the scene has a cube with the texture used on one side of it, but the color red is used on the other parts, resulting in something like this (in the rendered view):

All of this combined shows you how to add a texture to a model already built, and maintaining the material for the other portions.  It will be affected by the specularity of the material if you have adjusted that.


How do I scale an angled bone on only two axes?

Select pivot you do not want to move, press Shift + S  Snap Cursor to Selection , press . (Period) key select 3D Cursor the bone will then scale away from the 3D Cursor. Don't forget to press . (Period) and reset to Median Point afterwards.

To see through one bone to another you can toggle Xray in the top right hand corner of the viewport
This will put the bone in the right place, but it will not connect it. To do that, you might be better off not using duplicate (Shift + D ), but rather using extrude (E ), which will branch out a new, connected, parented bone from whatever bone is selected.
I'm not sure what you want here, but if the 3D cursor way is what you need, remember to switch over to the bone tab in the properties editor and change the new bone's parent, probably also checking the box Connected.


You animated the movement of the armature in object mode, but you should always use a root or ground bone in pose mode to animate the movement: Root bone as pelvis vs ground?

What you can do if you don't want to redo the whole movement animation is parent the object armature to an empty and use it to move or rotate said armature.


When i click to do stuff with retopoflow nothing happens cursor just moves around?

Never mind I had to press control while clicking for results.


Two Different Materials in One Particles System

You can use a black and white texture mask (in this case the alpha channel of the blender logo) to mix between two shaders:

Note that you need to UV unwrap your plane in order for this to work:

With the plane selected, press Tab to enter edit mode.
Press A to select all.
Press U> Unwrap.


Is Texture Paint While In Viewport Render Possible With Cycles?

No, render view in Cycles will not update as you paint, no fix for this.
I have spent a lot of time painting in blender, and in the newer post 2.8 builds I find that either Solid View or Material Preview are the best to paint in regardless of which renderer I have set up, and for preview of the paint I swap to the Shading workspace to see it or just set up a duplicate editor in a small view and set that one to render view.


How do I export non-face edges with Blender's Python API?

I'm not familiar with a direct method to get the list of free-edges (not comprising faces), but you can find them using this script:

import bpy, bmesh

o = bpy.context.object
bm = bmesh.new()
bm.from_mesh( o.data )

faceEdges = set( [ e.index for f in bm.faces for e in f.edges ] )
allEdges  = set( range( len( bm.edges ) ) )
freeEdges = allEdges.difference( faceEdges )

print( "Indices of non face edges: ", freeEdges )


Is there a way to easily blunt a corner vertex into three vertices?

ctrlshiftb works fine. But you need to make sure, your surrounding geometry has good topology. If you bevel the vertex of a non-planar face for example, the silhouette of your object may chance dramatically.

First two bevels on planar faces, the third one is non-planar.


Select everything visible with the lasso tool ( ctrl ), then inverse the selection with ctrl i, then X to delete.


Duplicating surface of cube adds a circle to it

This is because when you duplicate the face, it is now a flat plane and the subdivision surface modifier is treating it as a separate mesh and rounding it.

To get around this, you can disable or hide the modifier while working by clicking the eye icon  on the Subsurf modifier.

If I also understand what you are trying to do, it's also worth noting that you don't need to duplicate the face to apply a material to it or to modify it specifically. Objects can have multiple materials in Blender. You can go to the material tab, select a specific face, add a new material and apply it specifically to that face by clicking Assign.


Strange shading after running python script

The "lines" are where you have duplicate vertices where you have re-joined your mesh. You can see a slight variation if you enable vertex normal display.

The solution is to remove doubles in python or manually with W->Remove Doubles.

bmesh.ops.remove_doubles(bm, verts=bm.verts, dist=0.02)


Matching blender dimensions to paper cutout

Tried with a Cube and seems to be working.
But there is one thing that could be good to discuss with developer of this addon on Blenderartists

Cube

Object Dimension set 0.2 m
Object Scale is always better to have a 1 (Apply Scale Ctrl+A)

Addon

press Unfold
or select edges press Mark as Seam and press Unfold

Export (or skip for now)

Model Scale 1
Page Size 1 m

When export window popups go to options (right up gear icon)

it seems addon does not respect export setup from 3Dview
by default addon change scale automatically to fit A4 paper format

change scale to 1
if format is not enough for unfolded object it warns you

change paper format, addon will inform you if it is enough


Feed values into Crop Node (Left, Right, Top and Bottom)

QUICK UPDATE

Found a workaround, just used an array of nodes that had x and y inputs

Going to crop manually later using another crop node


Add a Cube
Extrude its two opposite vertical side
Merge the new upper verts to the originals to create a frustum
Extrude the frustum's upper side
Select all the non horizontal edges and choose Edge>>Subdivide
Select the new edgeloop around the frustum and move it to the right position by double hit "G" and move the mouse vertically.
Extrude the appropriate faces.


How can you create detailed low poly meshes?

Yes you can do the exact same thing with blender if you know how. Usually from a game asset modeling standpoint, the steps would be...

Created the initial model in the highest resolution possible.
Retopology. Meaning recreate the model in low poly count.Using surface snaps or retopo tools.
Unwrap the low poly mesh, and bake the high poly model's normal onto the low poly model. - affectionately known as "texture baking".

Note
The step 3 above enable game artist to fake the amount of mesh details on any given low polygon model. All of todays AAA titles base model details comes from normals map.**

Create textures, eg. diffuse, specular map, height map and ambient occlusion map ... etc. ( Using photo texture or hand painted ones. )
Export to fbx and import the data into a game engine, eg. Unreal or Unity.


How to model a letter K (or any other object made out of transformed copies of itself)?

Add a cube and Z upscale it;
Copy it with Shift+D;
Move the copy +1 grid step along X axis and shear it;
Combine the two cubes;
Use mirror modifier.


How to get a Fresnel node to only affect one part of an object? Ie) The top of an object

You are currently blending the fresnel and topside(normal) masks using a mixRGB node set to "mix". This gives you a blend of both masks. Sounds like what you're actually after is the area where both masks are non-zero, so the blending option you want is "multiply". You can either change the mode on the mixRGB node to "multiply", or replace it with a math node since these are float values (grey socket) rather than vectors/colors.


Solution: The gun and body armatures were separate, so I deleted the original gun armature and created one inside the body armature. Using IK that targets the last bone of the gun and uses the gun mesh as a pole. I could achieve an almost, if not completely perfect result.
Took me way too long to find it myself, so I'll leave it here for others, who suffer from the same problem.


First render out your animation with the OpenExr Multilayer setting, into an image sequence.

Then load the image sequence into the compositor (can be on a separate blender instance), with the Input -> Image Sequence node

Do whatever composite you desire.

Then in the Output properties tab, set your frame start and end, then change the output format to ffmpeg video. Open up the encoding tab that appears, and change the container and encoding settings to what you want.

Render the animation (Ctrl + F12) (find the output video file in the folder specified under Output. It should be named something like 0001-0250.mkv or similar)


Animated FBX Export Glitch - Foot Bones Jerking

I thank God for showing me the solution! All you have to do is add a "false foot" bone that is NOT a deform bone to each leg. I named this bone FootParent.

Connect this bone to the Lower_Leg bone (which has an IK constraint).  Set FootParent's Inherit Rotation and Inherit Scale to off, and add a Copy Rotation constraint which copies your Foot_IK bone (X + Y invert, Target: Local With Parent, Owner: Local).

Now duplicate this FootParent bone (or add a new one in the exact same location and orientation) and name it Foot. This will be your deform bone, and is NOT connected to anything.

Finally add 3 constraints to your Foot bone: Copy Location of the FootParent bone (Target: Local With Parent, Owner: Local); Copy Rotation of your Foot_IK bone (X + Y invert, Target: Local With Parent, Owner: Local), and optionally Copy Scale of your Foot_IK bone (Target: Local, Owner: Local). Now all your animations will export to FBX the way you created them in Blender!


Emission material changing global lighting?

In your render settings, your Light Paths options are configured to some very low values:

Compare these to the default values:

In particular, your Clamping settings are highly unusual. The default value for Direct Light is 0.00, which disables clamping altogether, but you have it set to 0.63, which is quite small. This essentially means your entire scene will be unusually dark, since the contribution of your direct lighting is artificially clamped.
Without the Emission providing an additional light source, Blender’s color management largely masks the effect of the clamping. Since the scene is uniformly dark, the brightest point is still the background, which will be chosen as the scene’s white point, scaling everything back to what is roughly normal.
But when you add the additional light source, that stops being true. Your sphere becomes the brightest object in the scene, which shifts the white point upward, above the value reflected by your background. Consequently, the background appears darker in the final composited image.
Resetting all the Light Paths options to their default values fixes the issue, so the background is consistently exposed regardless of the strength of the emission:

(Note also that the glass sphere looks much better with these settings, a result of raising the number of transmission bounces.)


Image as Plane and Stroke Object - transparency issue

You dont need to fix curve appearance, problem lies in imported Image as Plane that is by default set with Alpha Blend type.

Select Image object
go to Material Properties > Settings panel
change Blend Mode > Alpha Clip