How to bridge edge loops with a twist of .5?

It just so happens I modeled a Mobius strip a little while back, and I'm sure the technique I used can address your case as well.

Model a plane, or some variation of a plane. Best to keep it simple at first.
Place an Empty at the end of your object. Actually, it should be a little further from the end of your object, but we'll adjust it later.
Select the Empty, then the mesh object.
In Edit Mode, with the end vertices selected, Hook those verts to the Empty Ctrl + H (Hook to Selected Object).
Add an Array Modifier to your plane/mesh object. Choose Object Offset and point it to the Empty. Set the Count to 3 or 4 iterations so you can see the effect.
Now in Object Mode rotate that Empty and you'll see that mesh twist like a DNA double-helix.
This will probably need some fine-tuning, so in Edit Mode with those same end verts selected you can un-hook the verts (also Ctrl + H]). Then move the Empty and re-hook the verts. You can play with it until the positioning is right. It's hard to describe this part, but if you try it you'll get it.
Finally, you should have a strip that you can twist and stretch using the Empty.
Once you've twisted the strip to the degree suitable for your design, save your file, then apply the modifiers.
Place your 3D cursor where the center of your ring will be and align your view accordingly, then use the classic warp tool - Mesh > Transform > Warp to wrap your mesh into a ring shape. Remove Doubles.

Another way to to this would be to use the Curve Modifier, but it won't give you an evenly incremented twist like this technique does.

For anyone creating a (Mobius strip like) twist where the normals oppose each other where they meet, there is the additional challenge of how to merge these, which I will briefly address. Here, the vertices at the edge where the normals are opposite have been ripped with pressing V.

Halving the Solidify Modifier's Thickness value, then duplicating the object and making the value negative on the duplicate is one way to fix this. Then you can apply the Modifiers, join the two objects, and merge the vertices at the seam. After that, additional clean-up of of the mesh, such as the deletion of internal faces may also be necessary.

Once the two objects have been joined, and vertices welded, here is the final result:

Two .blend files for reference:

http://www.pasteall.org/blend/36552

http://www.pasteall.org/blend/36553


Here is a node tree to create a spiral from a Wave texture. It takes generated texture coordinates, splits them, and converts them to polar coordinates with the atan2 node and the Pythagorean theorem. It then adds the coordinates together so that the texture rotates as you get away from the center.

The Greater Than node acts as a threshold, to have a clear separation between black and white.

To change the direction and rotation speed, you can tweak the light grey Multiply node in the center. Value is the rotation speed; sign is the direction.


In your case, I would keep just the top and bottom edge loops and delete everything in the middle. To select the edge loops ShiftAltRMB on the top and bottom, then Invert I and Delete X.

Then use Bridge Edge Loops (which can be found in the Specials menu W).

You can adjust the parameters until you get edge spacing that is much closer to squares.

As Duarte Farrajota Ramos pointed out, you cannot get each face to be a perfect square, or you end up with a cylinder. But you can get even mesh density this way, which I'm guessing is what you are after.


If you're talking about the mesh visibility, it's normal you can't see some vertices as you've given your object a Subdivision Surface modifier. This modifier slightly deforms your surface, but the vertices are still displayed at their original position, so they might be hidden by the surface deformations. If you want the vertices to stick to the position that they will have once the modifier is applied, enable the modifier's On Cage option:

The other problem you're probably talking about is the fact that your vertices stick to the surface as soon as you're moving them, and that's because you've enabled the Snapping option:


Properties with min and max range looking at other property

The following example should point you in the right direction:
Any time the my_prop_range_min is changed in the UI the update function upd_min is called. The function then compares the UI setting to the current value of the my_prop_range_max. If the value of my_prop_range_min >= my_prop_range_max you just force it to be less than the value of my_prop_range_max. Similar when comparing max to min.
import bpy

def upd_min(self, context):
    if self.my_prop_range_min >= self.my_prop_range_max:
        self.my_prop_range_min = self.my_prop_range_max - 1

def upd_max(self, context):
    if self.my_prop_range_max <= self.my_prop_range_min:
        self.my_prop_range_max = self.my_prop_range_min + 1

class TEST_PG_props(bpy.types.PropertyGroup):
    my_prop_range_min: bpy.props.FloatProperty(
        name="My_Prop_range_min",
        default=1,
        min=0,
        max=99,
        update=upd_min,
        )

    my_prop_range_max: bpy.props.FloatProperty(
        name="My_Prop_range_max",
        default=4,
        min=1,
        max=100,
        update=upd_max,
        )

class TEST_PT_test_panel(bpy.types.Panel):
    bl_idname = "TEST_PT_test_panel"
    bl_label = "Test Panel"
    bl_space_type = "VIEW_3D"
    bl_region_type = "UI"
    bl_category = "Test Tab"

    def draw(self, context):
        my_props = context.scene.my_props
        layout = self.layout
        row = layout.row()
        row.prop(my_props, "my_prop_range_min", text="min")
        row.prop(my_props, "my_prop_range_max", text="max")

classes = [
    TEST_PG_props,
    TEST_PT_test_panel,
    ]

def register():
    for cls in classes:
        bpy.utils.register_class(cls)
    bpy.types.Scene.my_props = bpy.props.PointerProperty(
            type=TEST_PG_props)

def unregister():
    for cls in classes:
        bpy.utils.unregister_class(cls)
    del bpy.types.Scene.my_props

if __name__ == "__main__":
    register()


Is losing my settings upon updating a problem with the steam version of blender?

While the steam version automatically updates, it still stores the add-ons and config files in the same place. Blender separates every version and stores it in a folder named based on the version.

Those folders can be found under:

C:\Users\"Accountname"\AppData\Roaming\Blender Foundation\Blender\

Should look like this, instead of the red bar, well you know your accountname better then me.

and you should find one or more folders with the different version numbers.
Most likely 2.81 and 2.82 now, you can then rename the 2.82 to 2.82-bak for example and rename the 2.81 to 2.82.

That way you should have all the settings from the 2.81 taken over. Otherwise you can go through the files and manually pick which files you may want to keep.

As long as you do not use files from 2.79 and before, you should be fine.


How to smoothly combine objects at a right angle?

I personally think the imperfections in your joined planks look good.

However for a precise approach consider the following. The Knife Tool has the option to cut in steps of 45°.

Go into edit mode. ↹ Tab
Use the Knife Tool K to cut a 45 degree angle by pressing C once to activate snapping duration the operation.
Remove the vertices which are not needed. X
Snap the cursor to the outer corner where the planks join. ⇧ ShiftS > Cursor to selected
Select all A and duplicate the geometry ⇧ ShiftD. Let it rest in the same place.  RMB
Activate Cursor as Pivot NumpadPeriod, then rotate the duplicated geometry 90 degree around the cursor pivot. R90⏎ Enter.
Mirror it in Y. SY-1 or ⎈ CtrlMY
Remove the double vertices. W>R


How to apply same keyframes properties on mupltiple strips in VSE?

https://docs.blender.org/manual/en/dev/animation/keyframes/keying_sets.html

Keying sets might have what you are looking for, although I do not know how to apply them to vse strips as its not stated how or if you can. Sorry if that's not helpful.


Composite image sequence only using one image in the sequence

EDIT: The settings in the Image Sequence node are a bit different then I epxlained before - my answer only worked because I tested it with an image sequence starting at frame #1 - while yours beings with #884. So here's how it all works together:
Your mistake is, you have set an Offset of 883 in the Image Sequence node and set your animation to render from frame 884 to 1271 (my month and year of birth :D ), while at the same time you have set Start Frame set to 1 in the Image Sequence node - but your animation starts at frame 884.
What the three values Frames, Start Frame and Offset do is the following:

Frames tells Blender how many images are in that sequence
Start Frame tells Blender on which frame the sequence should begin to run
Offset tells Blender what to add to 1, to get the image number on the specified Start Frame

So, in order to make this work you must either render the animation from frame 884 to 1271 and make Blender believe you have 1271 images starting at frame 1, set
Frames = 1271, Start Frame = 1, Offset = 0
in the Image Sequence node. This will render on each frame the image with the same number as the frame. So image#0001 on frame  1, image#0002 on frame 2 etc. Since your image sequence starts at #0884, the frames 1-883 will stay empty and the frames will start getting rendered at frame 884. If you would have set Frames to 388, then Blender will stay at image#0388 until the end of the animation which is not what you want (because there is no image#0388).
Or the better and more correct way would be, you render your animation from 884 to 1271 and set the following values in the Image Sequence node:
Frames = 388, Start Frame = 884, Offset = 883.
This way you can set the actual number of images your sequence has, and Start Frame tells Blender on which frame you want to render the first image of your sequence. Since the first image is usually #0001, you have to enter the Offset to tell Blender you don't want to begin with image #0001, but with 1+883 i.e. image#0884.
Whatever the range of your animation might be, let's say you want an animation starting at frame 1 and ending at frame 3000 - that's not really relevant for the Image Sequence node. You can render frames 1-3000, and if you want your image sequence to begin at frame 100, then set Start Frame = 100. Blender assumes you want image#0001 on frame 100, so you need the Offset = 883 to correct that.


Yes, there are

Possibilies:
- Make sure you are in Blender internal
- Shading panel may be collapsed, or dragged below.


I had a similar problem where I was using a screen-capturing device that output some strangely encoded mp4 files. Whenever I tried to edit these in Blender, I had the same troubles you describe.

I fixed the issue by converting these strange mp4 files to a standardized format that blender can easily recognize. Here is the python script that I used, but you must have ffmpeg installed for it to work. To use it, save the text into a file that ends with .py and place it in the folder where your video files are stored (and no other files) and run the script:

import os
import subprocess

for file in os.listdir(os.getcwd()):
    if not file.endswith('.py'):
        filepath = os.path.join(os.getcwd(), file)
        outpath = os.path.splitext(filepath)[0] + '.mp4'

        if filepath == outpath:
            outpath = os.path.splitext(filepath)[0] + '_converted.mp4'

        subprocess.call(['ffmpeg', '-i', file, outpath])

If this doesn't work, perhaps you can provide a sample video that I can play with so I can find a better solution and edit this answer.

One problem with this method is that you lose quality everytime you convert and compress a video. If you have the hard drive space, I recommend altering the script so it converts the files to RAW avi files instead, like this:

import os
import subprocess

for file in os.listdir(os.getcwd()):
    if not file.endswith('.py'):
        filepath = os.path.join(os.getcwd(), file)
        outpath = os.path.splitext(filepath)[0] + '.avi'

        if filepath == outpath:
            outpath = os.path.splitext(filepath)[0] + '_converted.avi'

        subprocess.call(['ffmpeg', '-i', file, '-c:v', 'rawvideo', outpath])

The added benefit would be that you would no longer need to make proxy files.


I need to add finger rig to a model that is already rigged

I Googled further > found that I can select the main rig/metarig > go to Edit Mode > Go to Object Data > scroll to Rigify Buttons > Add two palms bones and the 10 fingers (by selecting each and clicking Add Sample) > scale them and link the joints respectively after. Doing this now and expect it will be all I needed. Just wished I could mirror and thus cut the work in half :)


The 'Clamp Overlap' option is enabled on the modifier. Un-check this to have a bigger bevel.

I would then suggest immediately setting the bevel back to 0 as the current value will be very large.

Use Shift while dragging on the bevel width value to increase the value slowly.


blender cycle glass issue(2.8); It looks thicker than the actual thickness of an object

reduce the roughness on the glass material


Where to place origin when exporting to UE4?

In my experience I have found prefered origin placement. Dependant on desired result and/or alignment on a per-piece basis. However as a basic default it's best to place the origin centered at the bottom. It's also good practice to keep the bottom aligned to 0 on your vertical axis.

I am unsure about the Unreal Engine. But in Unity the Y axis is used for vertical instead of Z. As such in order to import properly I have found the mesh needs to be oriented with -Y as bottom & +Y as top.

Also, likely most importantly, be sure to apply Rotation & Scale. ( Ctrl + A )


Bottom Status Bar Doesn't Show Verts, Faces, Tris Information In v2.9a

As of Blender 2.9+ scene statistics are now part of the 3D view and integrated into each viewport.
That is where they always belonged, since each specific view could have different visibility and selection states, resulting in different statistics. This now allows showing more relevant information for each independent viewport, reflecting individual variations.
They can be activated from the Overlays Popover in the 3D View Header.

To mitigate the lack of an unobtrusive way to display global scene statistics without a permanent overlay over the 3D View, and still be able to show system stats like available memory, customizable statistics to the status bar was reintroduced in 2.90.1.


This can be done by building the torus from 8 different vertex objects, each with 2 Screw modifiers.
One Screw modifier for making a circular section of the torus, and another one to rotate or loop this circle around a center (with an offset) thus creating a torus. The torus turning into 2 rings, and the 4 corners of the hole, warrants the total number of vertex objects and modifiers.

Linking the Screw modifier Angle values with drivers allows a single Angle value to deform the torus.
Making the inverse of this was my starting point so all the drivers are linked to a modifier on the initial vertex I used to make this. In hindsight a bit of a weird place but it works just the same. (So changing the Angle value of the top modifier on the "Vert" object makes it all move.)
I intent to elaborate on this solution a bit when i have more time (especially if you are new to Blender, drivers might take some explaining), but in the meantime...
...Here is the file:

And here is another file utilizing Mirror modifiers on only (and reducing the number to) 2 vertex objects:


Why does my render have a gamma value different from the viewport?

I opened your file, made a render, too much exposure.
I went to the compositor, turned on the  "backdrop" functions, everything went OK, even the animation rendering!

Looks like a little bug.


Any way to "thicken" my model without scaling it?

Well, it turns out I should have kept trying for another half hour before posting.
For anyone else with this problem, select all in edit mode, hit Alt+S to scale along normals, and then, while scaling, hold Alt or S to use something called Even Thickness to keep it from "bubbling" out.
I'll wait a while to mark this as my answer, in case someone else has another option that works better


How to dynamically paint cycle materials?

You can use an image texture that you paint on as a stencil between shaders, and this acts like a layer mask in Photoshop. You can also set up an attribute node and use vertex paint, but the effect there is limited to your geometry.


Seeing an outdoor scene in the reflections of my objects while in "material preview" mode but not in "rendered" mode?

Material preview uses a hidden HDRI to provide lighting and reflections. If you want your own lighting in Material Preview, click the little down arrow next to the preview mode "circles" to open the Viewport Shading options menu, and check "scene lights" and "scene world".
Material preview also uses a renderer much the same as EEVEE to allow for fast previews of your materials, however you are using Cycles for your main render. Things such as transparency are handled differently in this mode, hence why your glass looks "strange".


There exists a workaround (at least it works 100% in my setup)!

I have enabled Export Animated Mesh option for all moving fluid obstacle objects and it works!

The only downside is that it enforces No Slip and is slower according to the documentation inside Blender.


Blender 2.8: units of scale, grid, and default size of objects

Scene > Units > Units Scale $0.001$, Length > Millimeters

Viewport Overlays > Grid Scale $0.001$

File > Defaults > Save Startup File

Restart Blender, then
Add > Mesh > Cube, Torus, open the sidebar to check


Since 2.8 is changing every day there is no point for add-on creators to make their add-ons compatible with it, because the next update could make it incompatible again, which means many of them most likely won't be available until after 2.8 is officially released. For now though you could follow the tutorial in 2.79 and append it over to your 2.8 file.


Cycles

I don't know of any way to render edges like this natively in cycles, however the screw modifier can add geometry to edges:

It's a bit of hack, but I don't know of any faster way to add faces to edges using modifiers (it's not actually that bad, in most other cases using the screw modifier you would probably use only edges anyway).

Blender Internal

You can render edges using a Wire material:

Opengl

Of course, the viewport can render edges, however you are pretty limited in terms of controlling the color..

This patch may help though.


How do you scale the diameter of a cylinder and torus?

Than you want to scale radius of torus-like objects, the simplest way is using Alt+S Shrink-Fatten:


Understanding automatic key frames insertion

The red button in the timeline enables the Auto Keyframe function.

By default, autokeyframe will create a LocRotScale keyset. So even if you changed only one thing and left the rest untouched, it will create 9 keyframes, one for each axis of the Location, Rotation and Scale.

If you only want to record a specific channel with autokeyframe (for example rotation, but not Location or Scale) you can create a different keyset by left clicking here:

And enabling "use Active Keying Set Only"

Your changes will only be recorded for the current Keying set.

You can temporarily disable the use of "Active Keying Set Only" and make changes in other channels (like location for example) and the autokeyframe will revert to the default behavior of recording LocRotScale.


Is it possible to join all objects into one and their animations into one?

If I understand your question you have several animations to put in one.

It would use a null object (empty) and link your animations + mesh top.


How do I get imported objects to show in view? (.wrl files)

Select all objects in the outliner or other means. Press the home key ... the one NOT on the numeric keypad. (there are two home keys on many full size keyboards)
After that is successful. Consider press numeric keypad 0 a couple of times to switch bebtween

User View and Camera View.
Press Control Alt (Numpad) 0 to align the camera view with the user view.


Shrink Wrap Modifier producing unexpected results

You need a high-resolution plane for the shrinkwrap. Subdived it multiple times with "W"&"S" buttons in edit mode.


'Tris to Quads' on narrow faces does nothing

Try increase the maximum angle threshold, this will give you quads, but they won't be very square.

For better results, run: Mesh -> Faces -> Beautify Faces first.


I think it is just a marker. You can add it by pressing M and delete by selecting it and pressing X

If you can't select it, uncheck Lock Markers option in the Marker menu.

You can find more info about the markers in Blender Manual:
https://docs.blender.org/manual/ko/dev/animation/markers.html


2.83: assign same materials for objects created by array modifier

If your house base model is a continuous mesh (no loose parts), once the modifier is applied, go into edit mode, select everything and press P > By Loose Parts.
Go back into object mode with TAB.
With everything still selected, Right click > Set Origin > To geometry.
Press CTRL+ L > Object Data. Now when you modify one object's materials, they will all update.
In the end, while everything is still selected, go to Object > Relations > Make Single User > Object & Data and then you will be able to tweak each individual house separately.
Obviously it is better to do it before applying the modifier to avoid any of this.
PS, next time please take more time to write your question so there is less back and forth in the comments :)


Chest Bone Moves Unwantedly With the Hip Bone

You appear to be using the initial metarig which rigify provides for you to scale and position to suit your character. After positioning this rig to your model you should then generate the animation friendly rig.

The initial metarig -

The generate button is available in the armature properties

The animation rig that gets generated -

Notice that when the final rig is active it displays a rig layers panel in the properties sidebar (press N) and while in pose mode a rig properties panel is available showing properties of the selected bones.

CGCookie has a tutorial on using the rigify addon that demonstrates the steps needed to use rigify.


How to open .blend files with the Steam version of Blender on Windows?

I know this is not exactly what you want, but I can't see any reason why download Blender from Steam and make trouble by myself, when I can download it from blender.org without any trouble and without running unnecessary steam client on background.


How to create a 3D presentations using Blender?

I've seen this done before (yes, Blender as a power-point replacement).

Using Camera Switching

Blender can use timeline markers to switch cameras.

This means you can jump between markers to switch slides.

You can have 3d text in each view, and animate the visibility if you rather they don't display in every slide.

This also has the advantage that you can press Play and watch the full presentation.

See: How do I cycle through the camera views?

Using Scenes & Screens

You can configure each screen in blender to be a slide in a presentation.
Then use Ctrl + Left/Right to switch.

Each screen can point to a different scene (or the same scene with different cameras in each viewport).

You can also make use of background sets (the ability for many scenes to share one common scene as a background). - see scene buttons.

Using background sets means you can have a common scene for the detail, and other scenes can overlay text or any elements you don't want to enable all the time.

Using Scenes & Outliner

This just means adding one scene per slide, and using the outliner to change between them, The small disadvantage here is you need to have the outliner open, so you can't switch slides fullscreen.

With this method you can still use background set-scenes, and its rather quick to setup. If you wanted to you could always add a key binding or addon to switch scenes without using the outliner.

Hints

Enable 3D View -> Display (Panel) -> Only RenderThis stops cursor, manipulator and other info widgets from drawing, so you can focus on the content
You may find 3D View Full screen useful to play the presentation,its setup to minimize distractions.

If you want to get rid of the header too - this can be toggled with Alt+F10.

This Python command will cycle to the next scene:

Code:

from bpy import context
context.screen.scene = bpy.data.scenes[(bpy.data.scenes[:].index(context.screen.scene) + 1) % len(bpy.data.scenes)]


I don't see any path for the character to run along so I'll include this link as to how to create a path and have avatars objects  move along them.  here
Instead of forcing the character to follow the path, place an empty there instead, have it follow the path, then parent your character to the empty, much as is done in this answer - here
This will give you more flexibility to steer the character's facing direction, rotation etc so it does as we do in real life, 'anticipate' the turns.
The running animation can run independently while the character is 'pulled' along the path by the Empty.


Align vertex into a straight line non paralel to an axis

I have realized what can be done. Scale it on the z axis to 0, and then rotate the whole selection.


What's the easiest way to make consistent simple walls?

Solidify modifier.

For recent builds (2.82) with the complex mode

Consider using the solidify modifier. Model your walls as simple edges on the plan.. When done extrude to wall height to. Add a solidify modifier to give walls thickness.

Fiddle with settings, for example making offset negative half thickness will keep original edge mid wall.


How do i get rid of these black shadows?

By increasing the Transparency Max from 4 to 24 (with some trial and error), I was able to successfully eliminate the all of the shadows from my animation. I originally tried increasing the Bounces Max to 48 with no success, so I dropped it back to 4, then increased the Transparency Max amount and everything worked.

Thanks to everyone for their help and suggestions.


Baking Glass and Glossy materials Cycles

Baking for RT Render Engines explained

One of the common misconceptions about baking is that people think they can use a render engine to "bake" materials for game assets.

In reality you can bake only certain aspects of a material into a texture. These are obviously diffuse maps, normal maps, displacement maps,  ambient occlusion maps and certain hybrid forms of them ("albedo" as a new term for "diffuse + light/shadow values", for example). Furthermore you can bake certain "helper maps" to help a RT render engine to generate physically based or dynamic aspects, like specularity and lightmaps.

Specularity maps are black and white or greyscale images that are are processed by any real-time render engine where black is interpreted as non-specular while white represents the opposite on that scale. They work, similar to normal and displacement maps, as non-color maps.

Lightmaps are similar to ao maps a static representation of light and shadow and their primary use is to reduce the GPU load on shadow calculation.

Other material aspects like transparency, translucency, reflection and refraction of glass-like materials cannot be "pre-baked", since they depend on the render engine's capabilities and techniques to generate them. If your game render engine is capable to recreate these effects, they have to be created in the game engine's material editor.

If this explanation answers your question, please mark it as accepted.


Background goes transparent when png UV map is applied

You want the alpha channel to control how the colors of the diffuse shader mix with your image. Use a RGB mix node.


Using Blender as a video editor can I only add an audio track without recoding a video track?

No, it can't.

Blender only sends its render output to ffmpeg internally which means it's being encoded (again when using decoded footage in the VSE). You can use Blender as a Frameserver as well, but that won't help you out either.

Instead you should use Avidemux or mkvtoolnix to accomplish your goal.

Edit: As pointed out by Troy James Sobotka in the comment below, using FFMPEG directly would be a solution:

ffmpeg -i video.avi -i audio.mp3 -codec copy -shortest output.avi


Is there any way to save my screen layouts across projects?

In User Prefrences > File:
Uncheck Load UI

Then, your window layout will be preserved regardless of what file you open.


In the Animation layout there is a "Dope Sheet" and summary. I resolved this problem by unchecking the lock icon.

This was my error:

  RuntimeError: Error: F-Curve with path 'scale[2]' cannot be keyframed, ensure that it is not locked or sampled, and try removing F-Modifiers

After turning the lock icon off it works!


How to duplicate and move a selected edge in normal direction?

There are several normal directions, not sure what you actually desire. In your figure, it looks as if you want to translate to the average vertex normal direction, but only in 2D.

Here's a 3D example using the bmesh module:

import bpy
import bmesh

me = bpy.context.object.data
bm = bmesh.from_edit_mesh(me)

active_edge = None
for elem in reversed(bm.select_history):
    if isinstance(elem, bmesh.types.BMEdge):
        active_edge = elem
        break
else:
    raise Exception("No active edge!")

v1, v2 = active_edge.verts
#co1 = v1.co + v1.normal
#co2 = v2.co + v2.normal
n = (v1.normal + v2.normal) * 0.5
co1 = v1.co + n
co2 = v2.co + n

ret = bmesh.ops.duplicate(bm, geom=[active_edge])
new_verts = [elem for elem in ret['geom'] if isinstance(elem, bmesh.types.BMVert)]

# Order???
new_verts[0].co = co1
new_verts[1].co = co2

bmesh.update_edit_mesh(me)


For quick results you could setup an environment texture in the world properties.  For this examples I used a free example from hdri-hub. Note that this only works for stills an animation would look weird.

You can also create your own panorama pictures (with limited quality) with a smartphone or tablet.


Lattice deformation (bending) - not having any luck

Add lattice modifier and subdivide if needed. Select the mesh on which lattice modifier you need to apply. Go to modifier tab in the lattice modifier in the object mode select lattice or with dropper select the lattice. Now select the lattice in the 3d view. Go to edit mode and with the verts selected move it where your satisfied.


Copying a meshes intersecting outline from the top down view

Via a script.
A "conic section script".
Define a plane via its global location and normal.  For example add a plane named "Plane" aligned to cut
>>> C.object
bpy.data.objects['Plane']

plane_co  Global coordinate.
>>> C.object.matrix_world.translation
Vector((0.0, 0.0, 0.0))

plane_no  Global normal. (its rotation x z axis)
>>> C.object.matrix_world.to_3x3() @ Vector((0, 0, 1))
Vector((0.8242384195327759, -0.06781885027885437, 0.5621669292449951))

Running this script will bisect the context object (with modifiers and shapekeys applied) using the plane coordinates supplied and create a new segment object.
import bpy
import bmesh
from mathutils import Matrix
from bpy import context

# cutting plane coords and normal (global)

plane_co = (0, 0, 0)
plane_no = (1, 1, 1)
project_to_ground = True

ob = context.object
# object with modifiers shapekeys applied.
bm = bmesh.new()
bm.from_object(
        ob,
        context.evaluated_depsgraph_get()
        )

bm.transform(ob.matrix_world)

bmesh.ops.bisect_plane(
        bm,
        geom=sum((bm.verts[:], bm.edges[:], bm.faces[:]), []),
        plane_no=plane_no,
        plane_co=plane_co,
        clear_inner=True,
        clear_outer=True,
        )

me = bpy.data.meshes.new(f"{ob.name}_Section")
bm.to_mesh(me)
if project_to_ground:
    me.transform(Matrix.Scale(0, 4, (0, 0, 1)))
new_ob = bpy.data.objects.new(f"{ob.data.name}_Section", me)

context.collection.objects.link(new_ob)

Related
Planetary system simulation with real orbital datas
How to extract side-view outline (e.g. top view) of a 3D object to 2D surface?


Adjust random seed of displacement textures

To get the equivalent of translating and scaling the texture space, you will need to use Object coordinates for the displace modifier.

This allows for displacement independent of the location of the object being displaced.

For example, using Global coordinates, let's say you want a rock to be in a certain location, but it is not being displaced in the way you want.
using global coordinates the rock can only be displaced in one way per location.

Using Object coordinates, you can adjust the displacement by moving the object being used as Texture coordinates without moving the actual rock.

If you then decide to move the rock but want to keep the way it is displaced, all you have to do is move both the rock and the Texture coordinate object.


Here is the title and ID for a youtube video that explains step by step how to render an animation.  He is excellent at explaining things and would do it better than I.  Hope it helps.
Title:  How to Render Animations in Blender
ID: dd5RT8rEPqU
Here's the link:  RenderingVideo


What is the difference between duplicating and instancing an object, in regards to the materials they point to?

By default materials are linked to the object data. Hence when you instance the object data you are not duplicating the material, or the users of the material.

When you AltD an object, you are keeping the same object data.
If you look at the Data tab of the properties window for any linked duplicate object, you will see that the Mesh Data has the number of users.

The material still only has one user because part of the object data is the materials.

However if the material link is set to "Object" then AltD duplicating an object will increase the user count for the material.


How to move 3D cursor to point in bezier circle?

This is probably more general than you need:

To establish a point on the circumference of a curve circle at a known angle from its local X axis.

Shortcuts for 2.79

Assuming a circle at an arbitrary location and rotation:

Select the circle. ShiftNumpad 7 align the view to it, and ShiftS put the 3D cursor to its center.
CtrlAltSpace create a custom orientation from the circle; Check 'Use After Creation'. ShiftA create a Mesh: Single Vertex. EXX the vertex outward in X of the circle's space, with snap set to 'Vertex','Active'.  There should be a control point to snap to.
RZZ the extruded vertex through the known angle, with '3D Cursor' as pivot.(Illustrated with a duplicate edge)
With the vertex selected, ShiftS snap the 3D cursor to it.

Your circle is probably already aligned to the world, so you may be able to skip the Custom Orientation steps.

In an even worse situation, though, where the circle's own control points are not aligned with its local axes (with Custom Orientation and Snap set as before):

Extrude a vertex to any available control point on the circle to establish a radius
Extrude another vertex from the circle's center, in the X of the circle's space (EXX) to any point outside the circle
Rotate RZZ the radius vertex about the center of the circle, with snap on, until the rotation snaps to the other vertex  you sent out in local X.


The zoom setting you find listed under View2D refer to flat layouts such as dopesheet, graph editor, VSE...

To adjust the UV/Image Editor zoom settings you need to alter the zoom settings found under Image.


Why is a PNG appearing transparent in solid view but not in rendered view?

You don't need the color as transparency,
and you don't need the last set of nodes.
Why would you have black transparency? It will make it opaque.

The  mix with a transparent shader should be at the end of the node chain.
Or you can just use the alpha input on the principled shader, as noted on the other answer.


Grainy rendering in Cycles even with Render Samples at a high number

To sum up what everyone said, you are only looking in the viewport. The viewport has the 32 samples, but the render has 20000.

To see the render, hit the render button, but be warned that 20000 is a TON of samples (if you need that many samples, you're doing something wrong). A few hundred will do just fine.


How to morph / merge / blend from one mesh to another?

I assume you want these two meshes to become one mesh, with a connection of some kind between them. If your meshes have the same number of vertices around their respective outer edges, it's as simple as follows:

First, if you want to keep those edges looking the same when you join them, you need to add a loopcut very close to them, then two more between those two. If you've already done this, or have applied holding edges in another way, feel free to skip this step.

Second, you need to remove the faces at the end of both objects that you wish to join, leaving only that outer edge. This will keep little dimples and grooves from showing up in your final work.

Third, make sure both edges have the same number of vertices. While this isn't strictly necessary for the next operation, it tends to make the mesh look bad, which is what you want to avoid. If they don't match, add loopcuts along either object until the vertex count for the outer edges are the same. (You can check this number without counting in the upper right of blender next to the menu bar. The first number is the number of vertices you have selected, and the second is the number of vertices in your object).

Fourth, hit the space bar and type in 'bridge', then select 'bridge edgeloops'. DON'T CLICK ANYTHING ELSE YET. Hit the 'F6' button on your keyboard. (If you're using a laptop, you may have to hit the 'fn' key simultaneously.) Adjust these settings until you get something you like, hit enter to confirm any typing, and move your mouse out of the menu. You may now move it around as you like and continue with your modeling.


m.ardito suggestion have worked for me. Ive had the same issue where there was no audio in rendered file. Than I realised that I can not hear audio also while scrubbing in Video Sequence Editor. Simple ALT+A have returned everything to normal.


How can I resize a displacement map in cycles?

If you are using the UV (also default) texture coordinates mode (with Point or Vector mapping), you can use the Crop Maximum XY values to scale the Displacement Texture up and down with the same values you used for Scale on the colour texture.


How can I make a more realistic glass shader?

This has been answered before with a very clear explanation here.

Using the Shadow Ray and Reflection Ray trough a Math/Maximum node to combine the glass and transparent shaders.

I'll just post the node setup here, maybe someone will find it useful.


How to make two armature actions into one action?

Armatures can be joined together using Ctrl-J. You can also copy keyframes between actions using Key > Copy Keyframes. So you could copy the keyframes from one arm, join it to the other, and paste the keyframes to the other's action.


why do i have a black and white mesh on solid view mode?

Maybe you are using the black and white matcap you can uncheck or change it on the right panel (press n to get access to the panel)


Why does F3 return nothing searching for dyntopo?

Dyntopo isn't displayed in the F3 Menu Search, since it's not a menu item.
However, you can find it through the Operator search.

Switch to Sculpt Mode
Check Developer Extras in Preferences > Interface (to enable Operator search)
Go Edit > Operator Search > Dynamic Topology Toggle


Check your texture setting in the material panel.  Try being in render mode rather than texture mode.  The render mode and texture mode can show different results.

On the texture panel. Select type Image. Open the image. Select Mapping UV Map.


Is there a way to have a mesh extrude or retract itself during an animation while rigging with bones?

Add a stretch to constraint to the bone that deforms the connecting rod. In the constraint settings you will also want to set volume variation to 0.0 so that the connector doesn't shrink as it gets stretched.


Scale Interior While Retaining Objects Scale

If you specifically want to use the scale command you can only do it using modifiers to add thickness, otherwise the scale command will also affect the thickness of the blocks.

Otherwise use the move command instead and move the vertex 2 units in X or Y.


Can I constrain an object size to Camera angle of view?

Actually, it can be done with both perspective and orthographic cameras. I would like to suggest the universal way, which needn't any reset on the current camera transformation:

For Perspective camera:

Enable Import Image as Planes and Simple Align in Addon list.
Import the target image as plane. When importing, Choose Dots/BU as Plane dimensions, and set the longest side of the image as Definition value. For example, if the image resolution is 1920 px x 1080 px, then you should type in 1920.
Set the render resolution the same as image, to set the correct perspective for camera.
With the plane selected, hold Shift to further select the camera, then find Simple Align tool in the Tool Shelf, click XYZ button to align both rotation and location of the plane to the camera.
Select the plane only, then input like this: GZZ=-focal_length/sensor_size. For example, if the focal length of camera is 35, and sensor size is 32, then press GZZ=-35/32. Then you'll get what you want.

For Orthographic camera:

As above.
As above.
As above.
As above.
Select the plane only, then input like this:
GZZ=-ortho_scale/2. For example, if ortho_scale=8, you should input GZZ=-8/2. Then Tab into Edit Mode, S8.

P.S.: Doing math while transforming is only available in Blender 2.70+. However, you can do the math elsewhere out of Blender, and paste the result in.


How to replace / swap frames in Blender VSE?

I did this only a day ago.  I'd changed the path where the videos were stored, and the strip after that went blank.  I pressed "N" from the VSE window, went to the right where the strip's properties showed up and clicked on the source folder, browsed for the new path, and bingo, that video came back with fading settings, keyframes etc, intact!

Hope this is all you need to do.  Just re-browse to the desired video.  If they all have the same number of frames you might get away with this.

An alternative might be to produce just the best quality video and convert/copy that to lower settings for preview etc.


The object is non-manifold and the main reason why are these edges holding the top part because technically they aren't holding it:

For now printer won't be able to decide where is the inner part of that, where is outer, just as Blender can't calculate normals for the object correctly.

If you really want to print this object the easiest way to work precisely is to duplicate and separate to another object the outline for those curved extruded parts in order to cut them with Knife project / Boolean once they are part of another object.

First copy the top part of the object with which is the profile of the curved part extruded from the bottom. Then either hide those vertices with Mask modifier or delete them. Then dissolve the vertices corresponding to the ones removed from the top, - they are just going through the bottom part faces and are creating intersecting geometry.

In the end you want to get the bottom part only without any additional loopcuts:

From here on get duplicated curved profile of the deleted geometry, extrude it to get a line of faces in the top and line of faces going down:

Add Boolean modifier to the original object shown above, set it to Difference and use this profile as cutter. Below the cutter is hidden and new geometry create with difference is shown:

Do the same for the other part. Then either extrude top part once more or (as is done in the file below) copy the one from the original mesh, clean it up from doubles and unnecessary edges to get even quads and join meshes (Boolean has to be applied first). Then select both lines of faces and run Bridge Edge Loops.

Here you can convert tris to quads or not - it's not quite important for printer, the geometry here is more or less clean.
What matters for printer here are quads / ngons which might not be flat (in your model this is the case), as well as overhanging faces which might or might not require fixing though this is more printing related question than Blender.

Download the file


How to connect mix RGB with Noise Texture nodes

If you just want to cover the texture in noise, just combine it with another MixRGB node:

If you want the noise to also affect the surface, just connect it to the Bump Node. I mixed it with white first so the effect is not too strong:


How do you allow an object to rotate around an axis?

I believe it would be easier to animate it, use shift + axis.

add a key-frame where it should start with the desired rotation, and then add other key frames where you want the 'fan' to turn and the angle of choice. (i chosen 359 because im not sure if i set it to 360 it would just not move, but go ahead and experiment! )

blender will automatically interpolate the key frames you set.

but if you really want accurate physics then im afraid i also don't know :(

but maybe this post will help.


Alt-click is not selecting edge loops in lInux

Alt key in most Linux window managers doesn't work properly with blender. You can configure it in various window managers, but the easiest solution for me is to shift+alt click. It will select an edge loop, but its in a "additive mode" so it works for selecting 1 edge loop, and continues selecting edge loops as if you are shift selecting multiple items.

Sorry if this text description is confusing, but try shift+alt click on the edge loop and it should achieve what you want.


In short, there is no way to override internal limits.

However blender has 2 limits per setting:

soft-limits: which is for number button mouse motion
hard-limits: allow you to type in more extreme values, but there still is a limit.

These let you enter lamp energy of 10000000.0 for eg.


2D stabilization causes stretching artifacts

Change the filter used for stabilization from bilinear to nearest or bicubic:


If all your trackers are the floor use the "set X axis" and "set Y axis" and redo "setup tracking scene".

It would be better if you had a few trackers on the wall or fence and you'd set those as "wall" in the orientation tab.

You can manually re-orient your solved scene in the 3D viewport by rotating  the camera. Just select the camera rotate it about 90 degrees on X. The trackers are parented to the camera, so they will follow all movement.

If you have a good camera solve (with errors under 0.3) it shouldn't be difficult to line all of your tracker marks at 0 on the z axis on a side or front view as they should be in one plane.

In this example the camera is solved but nor oriented correctly:

Manually rotating the camera to bring the right orientation (note the tracking points at the side view at the bottom, those are trackers placed on the ground):

Bringing the camera down to make the trackers on the ground be roughly at 0 on the Z axis:


How to make the Grid floor Axes (X and Y) visible with plane on Z height 0?

So if you want to work with even numbers and later transfer that to more complex scenes that are supposed to lie on a plane, I don't find that a very elegant solution. My main concern is that these colored axes (X and Y) should always be visible when several objects in a scene lie on a plane, which is simply more helpful for orientation and faster when working in three-dimensional space.
I remember when I first started this tutorial series a few months ago (the 2.8 version at the time), I didn't have this problem, I found it clear when I was in the viewport and could see very quickly in the camera view exactly where I was in space (solid mode). Maybe this has been changed in the latest version (probably for UI reasons).


You could select one vertex, ShiftS, 'cursor to selected', then . (to transform with respect to 3d cursor), select all vertices, S to scale, then X,Y or Z and then 0


delete your plane.
Shift A -> Mesh -> Circle -> Tab (edit mode) -> F -> Circular plane


how to keep sharp turns on model while sub surf modifier is active? (image inside)

Depending on what your mesh is like, there are several ways to do this.

3D Objects:
You can accomplish this with the shortcut Shift+E while in edit mode. Select the edge you would like to crease (the "seam") first, and then press 1 or move the cursor until the crease is maxed out.

2D Objects:
For two-dimensional objects (planes) you can use Loopcuts to simulate this effect. One of the main drawbacks to this method is your vertex count will be increased. Sadly the Edge Crease option does not work on 2D objects.

In edit mode, hover over the adjacent edges and press Ctrl+R, then click once and drag towards the seam. Now click again to finish the operation. Repeat for the other side.


hair simulation too slow and cache inaccessible

You should enable Hair Dynamics in order Particle System set to Hair mode to have cache, because

  When set to hair mode, particle system creates only static particles, which may be used for hair, fur...

wiki page.

This type of Particle System may be animated using the cloth solver.

Baking particle system may be neccessary if something happens in the scene, i.e. animation is involved. If dynamic hair is disabled, it seems like hair won't change, so nothing to bake.

After you enable Hair Dynamics, Particle System will be accessible for baking results and previewing animation when it's played (and so on):


Your bezier version has its Fill Mode set to Both, it looks like when you convert it to mesh it creates inner faces that are connected to your outer faces (edges must not be connected to more than 2 faces) and that mess up your geometry, so switch it to None, convert, and it works fine. Also don't forget to recalculate the normals (ShiftN).


It seems as checking Global Undo, in User Preferences --> Editing is solving that problem.


One Click is Detected as Multiple Clicks

Make sure that your sensor (whoever clicks)is set to tap mode


You can change the editor type in the dropdown icon in the header:

The one you want is the Properties editor.


Possible to put XBOX 360 Controller inputs with logic bricks?

I think you can use the Joystick sensor; However, you do have to configure it accordingly, using the button and axis numbers.


What happens when you zoom in ...

view >>>> clip start Reduce the size ....


Dust on image, using alpha node on a mask

Alpha over and Math nodes

When you want to overlay an image with transparency to another, the Alpha over node is perhaps a better coiche than any other node.

From the manual's page:

  Use this node to layer images on top of one another.

Example of usage:

Note that you don't even need to set the overlayed image's alpha, it is already taken into account.

One of the possible way to control the strenght of the mix could be lowering the incoming overlaying factor with a Math node:

While before the range of the factor was from 0 to 1, now are linearly remapped from 0 to 0.4, resulting in a softer effect.


Is there an Evaluation time/Speed graph for regular xyz location /rotation properties inside the graph editor?

The overall speed between keyframes can be only changed in the dopesheet or graph editor moving them, there is no built-in function to use a curve to control the timing.
To get this behaviour, you can use the action constraint: a single channel of a "controller" (like X loc of an empty or a bone) can be used to trigger the action of one or more objects or bones (like moving X loc 10 units means perform the action from frame 20 to 80).
Once the constraint is created, it can be easily copied to others objects or bones involved in the action to be retimed (i.e. select all objects involved, shift select the constrained one - last selected is active - and use the "copy selected contraint" function.
If the action is based on bones, the constraint has to be copied to all involved bones.

Another method is to load a rendered image sequence and retime it using  a curve to control.
To do this, add an image sequence as plane, create a custom property, edit its name and its limits (in my example "timing", and 1 - 80, the number of images on the sequence).
Then hover over its value and right click "copy as new driver".
Paste the driver on the "offset" value of the image sequence node in the shader editor.
Then edit the driver changing its result form "Average value" to "Scripted expression", tyiping in "var - frame# + 1" (in my example, as the name of the custom property is set to "timing", the expression becomes "timing - frame# +1).
Now you can animate the custom property value and edit its curves in the graph editor.


How to animate splines using animation node

ok, let's see how familiar you are: here is my guide for you:
Create a text, convert to curve.
Create animation node tree, get curve from object node -> loop over splines -> animate it with trim spline node and use curve object output to show them.
UPDATE:
The "trick" is to use a spline list:


How do I get my GPU to start running in blender?

Go to Edit>Preferences>System The at the top of the window you should see cycles render devices. Select CUDA and then check the devices you would like blender to use.


What's the purpose of Node Wrangler's Viewer Node?

It's a technical detail but using the Emission Shader as some kind of bridge is technically correct.

The color of each socket represents a specific data type. Quoting from What is the meaning of the color of the node sockets in the node editor?:

  Grey is a single value
  Yellow is a tuple containing 3 values; the red, green, and blue channels of a color.
  Purple is a tuple containing 3 values. Used for vector/coordinate information.
  Green is a shader closure, representing a description of how light will interact with a surface or volume. This one can only be connected into other green sockets.

As you can see the Surface socket from the Output node is green so it expects an incoming shader (closure) and no other kind of data. However, that you're allowed to plug any other node type into the Surface Socket is actually a great feature...

For the sake of completeness: In case a float socket (grey) is connected to rgb (yellow) the resulting g and b channels are just a copy of r to fill it up.


How to add an origin point without adding anything else?

This function is already delivered with Blender, just not enabled. Go to File > User Preferences > Add-ons > Add Mesh and enable Add Mesh: Extra Objects. Now if you press ShiftA in 3D View and go to Mesh > Single Vert you'll have an option called Object Origin Only. This will add an object origin in edit mode and you can start editing.


How to set glow in text object, with python?

The way you setup the scene, the glow is only noticeable if you have another object. It will not cause the 'air' around the text to glow.

Below is my test render when I run your script with a plane. I this what you want?

If you want the air around the text to glow, approximate ambient occlusion cannot give you that. You'll need to use the compositor.


Additional bindings for existing operations can be added in the Keymap Preferences.

Open up Edit > Preferences, and on the left column select 'Keymap'.

You can search for operators by name, although that doesn't help if we don't know the name, of course. It appears the one you're looking for is under:

> 3D View > Mesh > 3D View Tool: Move >

Under a plethora of options for this tool, there's a section further down that says 'Transform Modal Map', which lists all the bindings for all the sub-parts of the move tool. And at the very bottom of that binding list, there's a button 'Add new' which allows adding extra keybindings.

Set your new binding to the desired keys, performing the same actio that the existing G, X, Y and Z keys are set to already.


For anyone else with this problem the detailing of this is actually outlined in the blender docs here
The docs say:

Vertices:
Selects vertices that belong to wire and multiple face edges, isolated vertices, and vertices that belong to non-adjoining faces.

In the attempt not to repeat the good descriptions that exist elsewhere on this stack:

Wire edges: What are wire edges?
Multiple face edges:

Isolated vertices: https://en.wikipedia.org/wiki/Vertex_(graph_theory)#Types_of_vertices
Vertices which share non-adjoining faces:

N.B: if you hover over each option in the Select all by Trait menu you get a tooltip about each option:

This is all my best answer as to each scenario, if edits are required please go ahead


I've tried it this way:

Create bezier curves with bevel, convert to mesh, you have pipes.
Create a cube, Boolean it with the pipes.
Sculpt with Dyntopo to give it smoothness and bumps.
Decimate the mesh to reduce the amount of vertices. Give your object a Shading > Smooth.
Give it its surface bumps with a Noise Texture.


Depth information from pair of stereo images

Depth estimation from images is a well established field and Blender is not the software to go for. Look for keywords like 3D reconstruction, structure-from-motion, multiview stereo, stereo reconstruction, stereo depth estimation.
Typical approach will be to detect SIFT (or some other) features, match them, compute relative orientation of the cameras and then use something like semi-global global matching. The code you can find, for example, in OpenCV.
Look at this tutorial, which creates a disparity map. There is also stereo_match.py in OpenCV-Python samples. For feature matching look here.


How to use Blender object rotation style using Maya Navigation?

I don't know how it work in Maya, but in Blender you have this options:

1: Turn ON "Transformation manipulate"

2: Use this shortcuts: (I recommend)

"R" and after "X" = rotation arround X axis in global coordinates
"R" and after two times "X" = rotation around X axis - in local coordinates
"R" and after "SHIFT+X" - for rotate around Y and Z axes (no X)

This work for all axes obliviously and for "G" - grab, "S" - scale and "R" - rotation.


Making the "ruler" go along a perfectly straight line?

The work around would be to :

Press Tab
to Edit go into mode
Hit  N  to open the navigation panel in the 3d viewport
Go to "Mesh Display" section
Turn on Edge info : "Length"

What I usually do is to quickly duplicate a vertex and extrude it to make
an edge. Move the vertex while holding on to CTRL  will move your vertex while
using snap. Make sure your snap tool is set to snap to vertex, closest and also
turn on snap to self. The edge would have the distance displayed between the 2 vertex with the above options turned on.

This way it makes the ruler tool quite obsolete for measuring straight / linear
distances.


Realtime auto keying framing on the timeline don't work as expected on blender 2.81

If you need to record an animation on the fly, you have to start the playback first. So that time goes on in Blender's point of view and it can record what you each frame passing by:

Without that, time isn't involved, only the frame under your playhead can be keyed, and it will only do so when a transform is validated (like when you move your object somewhere and release your mouse button to confirm).

Hopefully this is just what you need.


Removing internal geometry before 3D printing

All internal faces can be selected by using Select > Internal Faces in the bar on the bottom of the 3D View in Edit Mode.

Since internal faces are Non-manifold geometry, you can also use the shortcut CtrlShiftAltM to select them, along with all other non-manifold geometry.

Once you have the offending faces selected, you can use Del>Faces to remove them without affecting the rest of your geometry.


I'm not entirely sure I understand how you cylinders are aligned towards each other, but it doesn't matter to much. I'm going to use the "bridge two edgeloops" operation.

Here is my starting position:

I edit both of them and remove the end caps.

Then I select them both and join them Ctrl + J. Now I again go into edit mode and select both edgeloops at the end of the cylinders. Hold down Alt to select and edge loop. Hold down Shift + Alt to select the other without deselecting the first.

Then hit space and type "bri" in the menu. It should look like this. Hit Enter

Now the two edge loops should be bridged with faces:


It's more reliable to tell Blender which mode to switch to instead of relying on editmode_toggle(), because there's an enter editmode option, so you can't be sure what mode an object is in after creation:

bpy.ops.object.mode_set(mode='EDIT')

BTW: this is better than your current code:

try:
    armature = bpy.data.objects[armature_name]
except KeyError:
    # create armature


When creating a new image in the UV Image Editor, change the Alpha channel of the Color to be 0. Then be sure that the Alpha check box is checked.


How can I run blender from command line or a python script without opening a GUI?

Command-line / subprocess

You can use subprocess to run blender (like any other application) from python.
Use the -b / --background switch to run blender in the backgroud (GUI-less).
Use the -P <filename> / --python <filename> switch to load desired python script.

Or use --python-console to run python from stdin.

Example: blender --background --python myscript.py
See: https://docs.blender.org/manual/en/latest/advanced/command_line/arguments.html
As module
This is an experimental feature and not enabled by default, but Blender can be compiled as a python module.

This allows 'bpy' to be imported from python or other applications/IDE's which embed python


How can I use Cycles to render in Google Cloud?

I am not good in programming so I did it this way...

I install VM whit 8 cores Hight cpu 2,6ghz xeon whit 8gb ram... 50 gb HDD and Windows server 2012 .... Its exatly 274 dollars... On your free trial you have free 300 dollars... What is amazing...

After install VM , you can log in using Remote Desktom Connection... Open Internet Explorer, download Blender Zip file from blender.org...

And you can render under blender GUI..

Noob way whit using mouse and 0 commands...

:)


Is it possible to bake fluid simulation into blend file?

No, this is not possible currently.
I'm not sure how practical this would be, given the massive size of fluid caches.

As mentioned by stacker, ResPower supports fluid simulations to some extent.


Symmetrize Along Custom Transform Orientation

It works fine for me. I guess it's the matter of the proper placing of the object's origin point.

You may also try mirroring with Empty. In Edit Mode select the face you want to add a custom transformation to, press Shift+Alt+Spacebar to set it. Then press Shift+Num 7 to allign the face to view. Enter Object Mode, add an Empty and check the Align to View checkbox. Add a Mirror Modifier and set the Empty as a mirror object's target. Now translate the Empty or the object along your custom transformation.


How coould I scale a bone to fit inside the models body?

You cannot scale the default armature but if you change the bone display type to B-Bone, you can use CtrlAltS to scale it and make it thicker or thinner. It's also fairly easy to have the default armature display type fit inside any model by scaling it down in Edit mode and making it longer and thinner.


The flickering effect can be achieved by adding an effect strip on top of the movie clip.

Shift+A > Effect Strip > Color
Go to the Properties Panel of the video sequence editor (N)
Set the blendtype to Alpha Over
Set a keyframe on the opacity (also in Properties Panel) by clicking on I
Go to the graph editor and add a Noise Modifier (in the Properties Panel of the graph editor)
Tweak the different options in the Noise Editor like scaling, strength, phase the frame range etc.


Can't Keep Loop Cut & Slide Where I Want With Measurements

The loop cut tool or Loop Subdivide as it may be called, is a two step tool that subdivides the chosen edge loop and then starts an Edge Slide.

In the first stage you can use the  MW or numpad-/+ to increase/decrease the number of cuts being made. You can also press E to keep a single loop parallel to the next edge loop and F will flip that to the other side.

In the second stage you are sliding the new edge loop/s along the edge that you are subdividing, the value you enter is a factor relative to the edge being cut with 0.0 being in the centre and 1.0/-1.0 moving the new edge loop to either end of the edge being cut.

For more precise placement of vertices you want to use other tools that allow movement based on global position. The snapping tools make it easy to align items to each other.

When moving vertices and objects you can restrict movement to an axis and enter a distance to move. eg GX0.5 will move the selection 0.5 units on the x axis.

In the mesh display panel which can be found in the properties region N of the 3DView you can display the length of selected edges while editing.

The scene settings allow all sizes to be shown using metric or imperial units rather than an arbitrary unit.

As you are modelling buildings you might be interested in the Archimesh addon which you can download here - this addon has recently been added to the standard addons and will be included in the 2.78 release.


Force Blender to Select rig instead of geometry

For cases like this, I just switch to wireframe shading with Z, select the armature (which is now visable) then switch back to solid shading, again with Z.

Or you can turn off viewport selection, then you will not be able to select the mesh in the 3D view (you can still select it from the outliner).

Another option is to select the armature differently. AltRMB  on your armature, that will bring up a list of objects that is below the mouse. You can pick your armature from that list.


Overlay PNG image as overlay in camera view in BGE

If I got it, you could parent a plane that uses the image as texture (textured using alpha), like this:

start enabling the "import images as planes" addon (bundled by default), and import your overlay image

then enable alpha for the texture if needed, and transparency for the material

then look at the camera rotation transforms

and copy those values to the plane, and then move it towards the camera (translating on its local Z), to get:

in the end, here is an example of the camera rotating around a target object, and the view looking through the camera:


Why does this mesh deform while weightpainting?

if you switch your armature to rest pose in the armature tab, properties editor, you can be sure that all bones are in their default orientation and location, even with constraints on them. thats easier and faster than manually trying to find them and resetting values.


Edit all the parts of a cell fractured object at the same time

When joining objects, one object must be chosen to join all the other selected objects too.
In this case it doesn't really make a difference which object that is, but if you had different modifiers or materials on the objects, blender needs to know which object's modifiers should be used on the resulting combined object.

Normally this is done with the Active object, which is outlined in yellow and in most cases is the last selected object. Note that an object can be active without being selected.

Right after running the cellfracture operator is a rare case where there is no active object. You need to define one by selecting an object, but after you have done that, that object is active until you select another object and it becomes the new active object.

In the tutorial he uses ⇧ Shift RMB on a already selected object (orange outline) to make it active (yellow outline) without affecting the rest of the objects. I'm not sure why this didn't work for you (are you sure the object's outline didn't change color?), but you can just as easily select all the objects after one is active, e.g. with box select (B) or if you really want to select all the visible objects, A.
Once you have your active object and selection, you can join them with ⎈ CtrlJ or the join button in the toolshelf.


This delves into the concept of normals, and mathematical planes. My short answer is to extrude the plane a bit, then recalculate all the normals in the Mesh menu (make sure to select everything first). This will turn the plane from a two dimensional area into a three-dimensional object, and will allow it to emit hair from both sides.
If you don’t want the plane to be solid at all, I recommend changing how the hair is emitted to not use normals.


What is causing splotching on rendered image?

This kind of noise is usually caused by denoising. Lighting scenes with HDRI requires more computing and renders tend to be noisier for longer. What we see here is likely denoiser failing to cope with increased amount of noise. You should increase sample count and use light portals to combat this issue.


You can access it at shape_keys.animation_data.drivers.
import bpy

shape_key = bpy.context.object.active_shape_key
if shape_key is None:
    raise()

shape_keys = shape_key.id_data
if shape_keys.animation_data is None:
    raise()

for fc in shape_keys.animation_data.drivers:
    print(fc.data_path)
    print(fc.driver.type)

Hierarchy

Direct access
>>>
>>> def fn(name):
...     if name == "":
...         print(False)
...     else:
...         print(name)
...
>>> fn(bpy.data.shape_keys['Key'].animation_data.drivers[0].driver.variables[0].targets[0].bone_target)
False

>>> bpy.data.shape_keys['Key'].animation_data.drivers[0].driver.variables[0].targets[0].bone_target = "Bone.001"
>>>
>>> fn(bpy.data.shape_keys['Key'].animation_data.drivers[0].driver.variables[0].targets[0].bone_target)
Bone.001


This is not possible in official blender at the moment, however this feature was written as part of the 2013 GSOC.
I haven't seen word of it since, so if someone knows why it hasn't been integrated with master yet, please tell me :P

The closest you can get is the Mesh collision shape:


Everything is working just fine.

Try to Remove Doubles, and double check your mesh for any errors. Also Apply Scale to it.

Here is whole process.

Select All - A.
Press I for Inset.
Move mouse to get wanted offset.
Move created geometry along Z axis - G>Z.

Edit for incremental height:

First of all you will want to use different topology for this case to prevent faces becoming non-planar after couple of insets.

Than you should follow simple procedure: Inset I > Extrude E and repeat as much as you want/will be able to.

Edit 2:

No, there is no easy or efficient way to do this by outseting whole shape or extruding outwards.

You can make the biggest step, than inset to the smallest and after that start outseting from the smallest (bigger loops first), like so:

As you can see this method is quite strange and after this you will need to select each loop and extrude it individually.


How do I change the value of the "To:" text field on the Message actuator?

You need logic set up like in the image below on each of your markers.

It is just an Always sensor, set to True level triggering; and a Near sensor. Those two are plugged in to the python controller, which will activate the message actuator. The property in the Near sensor is not needed, that is only to limit what objects get the message.

The script will send a message to every object that is near (3 units or closer) the marker.

import bge

cont = bge.logic.getCurrentController()

list = cont.sensors['Near'].hitObjectList

if cont.sensors['Near'].triggered:
    message = cont.actuators['Message']
    for obj in list:
        message.propName = obj.name
        cont.activate(message)

The script gets all the objects that are near the marker and stores it as the list variable (line 5).
The if statement works like this, when anything is near the marker, the near sensor is triggered, thus it is True.
It then loops through the list of objects that are near, and sets the message actuator's "To:" field to one of the objects. (message.propName = obj.name)
The last line still part of the loop, activates the actuator - sends the message.


Simply click the Apply button of the decimate modifier. You must be in Object Mode for that to work.


howto create glass test tubes with semi-transparent fluid content

I've tried to composite three layers:

Glass material:

Fluid material:

Not ideal, but the best output I achieved for now:

I don't know how to make glass material brighter.


While I think there has been some work done to get blender running on an android device, I wouldn't recommend trying at this stage.

You can export your 3D models and open them in an Android application, though using Android studio would mean programming the game yourself.

I would recommend using an external game engine, such as godot or unity to create an android game, both of these can use the models you create in blender.


Removing objects from collection with script works but gives an error

I have enhanced and modified your code and, it works perfectly :

bl_info = {
    "name" : "Clear Collection",
    "author" : "CédricF",
    "description" : "",
    "blender" : (2, 80, 0),
    "version" : (0, 0, 1),
    "location" : "Sidebar(N)>Clean Up",
    "category" : "Clean Up"
}

import bpy

from bpy.props import PointerProperty

#----------------------------------------
#MAIN PANEL
#----------------------------------------

class CLEARCOLLECTION_Property(bpy.types.PropertyGroup):

    ClrByNameEnd : bpy.props.StringProperty(name= "All Objects Ending By", default="")
    ClrByCOLNameEnd : bpy.props.StringProperty(name= "Collection", default="")

class CLEARCOLLECTION_PT_MAINPANEL(bpy.types.Panel):
    bl_idname = "CLEARCOLLECTION_PT_CLEARBYNAMEEND"
    bl_label = "Clear By Name End"
    bl_space_type = "VIEW_3D"
    bl_region_type = "UI"
    bl_category = "Clean Up"

    def draw(self, context):
        layout = self.layout

        scene = context.scene

        CLRCTool = scene.CLRTool

        row = layout.row()
        row.prop(CLRCTool, "ClrByNameEnd", icon= "TRASH")

        row = layout.row()
        row.prop(CLRCTool, "ClrByCOLNameEnd", icon= "TRASH")

        layout.operator("clearcollection.clearbyend", icon= "TRASH")
        layout.operator("clearcollection.slecbyend", icon= "RESTRICT_SELECT_OFF")

#----------------------------------------
#CLEAR OBJECTS
#----------------------------------------

class CLEARCOLLECTION_OT_CLEAR(bpy.types.Operator):
    bl_idname = "clearcollection.clearbyend"
    bl_label = "Clear Objects"
    bl_description = "Clears objects which end with the given input"
    bl_options = {"REGISTER"}

    def execute(self, context):

        scene = context.scene

        CLRCTool = scene.CLRTool

        for obj in bpy.context.scene.objects:
            if CLRCTool.ClrByNameEnd != "":
                if obj.name.endswith(CLRCTool.ClrByNameEnd):
                    bpy.data.objects.remove(obj)

        for obj in bpy.context.scene.objects:
            if CLRCTool.ClrByCOLNameEnd != "":
                for objc in bpy.data.collections[CLRCTool.ClrByCOLNameEnd].all_objects:
                    if CLRCTool.ClrByNameEnd != "":
                        if obj.name.endswith(CLRCTool.ClrByNameEnd):
                            bpy.data.objects.remove(obj)

        return {"FINISHED"}

#----------------------------------------
#SELECT OBJECTS
#----------------------------------------

class CLEARCOLLECTION_OT_SELEC(bpy.types.Operator):
    bl_idname = "clearcollection.slecbyend"
    bl_label = "Select"
    bl_description = "Selects objects which end with the given input"
    bl_options = {"REGISTER"}

    def execute(self, context):

        scene = context.scene

        CLRCTool = scene.CLRTool

        for obj in bpy.context.scene.objects:
            if CLRCTool.ClrByNameEnd != "":
                if obj.name.endswith(CLRCTool.ClrByNameEnd):
                    obj.select_set(True)

        for obj in bpy.context.scene.objects:
            if CLRCTool.ClrByCOLNameEnd != "":
                for objc in bpy.data.collections[CLRCTool.ClrByCOLNameEnd].all_objects:
                    if CLRCTool.ClrByNameEnd != "":
                        if obj.name.endswith(CLRCTool.ClrByNameEnd):
                            obj.select_set(True)

        return {"FINISHED"}

classes = [CLEARCOLLECTION_Property, CLEARCOLLECTION_OT_CLEAR, CLEARCOLLECTION_OT_SELEC, CLEARCOLLECTION_PT_MAINPANEL]

def register():

    for cls in classes :
        bpy.utils.register_class(cls)
        bpy.types.Scene.CLRTool = PointerProperty(type= CLEARCOLLECTION_Property)

def unregister():

    for cls in classes :
        bpy.utils.unregister_class(cls)
        #del bpy.types.Scene.CLRTool

if __name__ == "__main__":
    register()


Move your empty closer to the camera and lower the aperture value, real world cameras also have approximately one third of DOF close and two third far from lenses.


Corrected by user "HG1" in blenderartists.
In the BA thread you can see the answer and a .blend file shared.
In short:

  Your expression is wrong "if ((cor_exhibit_door == stol_exhibit_door), True, False)" or "cor_exhibit_door == stol_exhibit_door".
  If you only want to activate the expression if are bot sensors active then you can add the names of the sensors to the expression. "if (Near AND E AND (cor_exhibit_door == stol_exhibit_door), True, False)" or "Near AND E AND (cor_exhibit_door == stol_exhibit_door)


From your screenshots, I see that the only light source that is present in the scene is the default point lamp.

It looks like this is not enough to light up your robot. Maybe try changing that to a sun lap, or boost the power of the overall lighting in the World settings.


How to show to the user a progression in a script?

Progress of script can also be printed and updated with sys module to the console:

import sys
from time import sleep

sys.stdout.write("Some job description: ")
sys.stdout.flush()
some_list = [0] * 100
for idx, item in enumerate(some_list):
    msg = "item %i of %i" % (idx, len(some_list)-1)
    sys.stdout.write(msg + chr(8) * len(msg))
    sys.stdout.flush()
    sleep(0.02)

sys.stdout.write("DONE" + " "*len(msg)+"\n")
sys.stdout.flush()

This can look like this:

You can also copy paste this next function to display a progress bar:

import time, sys

def update_progress(job_title, progress):
    length = 20 # modify this to change the length
    block = int(round(length*progress))
    msg = "\r{0}: [{1}] {2}%".format(job_title, "#"*block + "-"*(length-block), round(progress*100, 2))
    if progress >= 1: msg += " DONE\r\n"
    sys.stdout.write(msg)
    sys.stdout.flush()

# Test
for i in range(100):
    time.sleep(0.1)
    update_progress("Some job", i/100.0)
update_progress("Some job", 1)

This results in:


How to flatten the curve of a complicated STL

Select the parts of the object you don't want to affect and hide them with H.
Use projected proportional editing to adjust the model smoothly
Unhide the hidden parts of the mesh (AltH)


How to composite an image sequence rendered in PNG?

If your redered correctly, you should have an image sequece for each of the passes (image Sequence Emision, Image Sequence Diffuse, Image sequence Shadows and so on) if you only turn it on but did not save the passes, you need to start again. https://www.youtube.com/results?search_query=blender+how+to+output+passes


Is it possible to have a property sensor detect a value higher or lower than a specific number?

You mean like "Less than"?

A value less than 1 is either equal to or less than zero.

EDIT: the options for evaluating properties "Less Than" and "Greater Than" was added in blender 2.71. Previous versions don't have these options.

The easy solution would be to upgrade to 2.71, another option would be to use a python controller to do the test of the property value.


Error: Object has no mesh data to be used for ray casting

You need bpy.context.scene.update() just after execute() for it to work. It seems it needs to update some internal relationships.

Full code (modified to work on 2.78):

import bpy
import bmesh
from bpy.props import *
from mathutils import *

class SomeOperator(bpy.types.Operator):
    bl_idname = "object.some_operator"
    bl_label = "Some operator"
    bl_options = {'REGISTER', 'UNDO', 'PRESET'}

    prop = IntProperty(name="Prop",
        description="Prop",
        min=10,
        max=50,
        default=10)

    def execute(self, context):
        bpy.context.scene.update()
        obj = context.active_object

        if bpy.context.mode != 'OBJECT':
            raise Exception("Please switch to object mode")

        cover = [Vector((0,0,1)), Vector((0,0,-1)), Vector((1,0,0)), Vector((-1,0,0))]

        for pt in cover:
            dummy0, dummy1, dummy2, faceInd = obj.ray_cast(Vector((0.0, 0.0, 0.0)), pt)

            obj.data.polygons[faceInd].select = True

        return {'FINISHED'}

def register():
    bpy.utils.register_class(SomeOperator)

def unregister():
    bpy.utils.unregister_class(SomeOperator)

if __name__ == "__main__":
    register()

# test call
#bpy.ops.object.some_operator()


Automate save as shapekey for multiple animation actions

i wasn't able to find a way to fully automate the task but was able to streamline and reduce the time it takes to complete it using this sequence in the command recorder addon Nascent Space suggested, from about 15 minutes to less than 2, so i'm satisfied
bpy.context.view_layer.objects.active = bpy.data.objects['M_Head']
bpy.ops.object.modifier_apply_as_shapekey(keep_modifier=True, modifier="md_chr0305_2064_hq")
bpy.context.view_layer.objects.active = bpy.data.objects['md_chr0305_2064_hq']
bpy.ops.object.posemode_toggle()
bpy.ops.pose.select_all(action='SELECT')
bpy.ops.pose.transforms_clear()
bpy.ops.object.posemode_toggle()


How do you import images onto planes using nodes

There is an add-on that allows you to automatically import an image as a plane:

when you use it to import an image it creates a plane of the right aspect ratio and a shader that displays the image:

If you want to change the image, so long as it has the same aspect ratio, all you have to do is click on the file folder and select a new image.

It can't get any easier than that


how to make a rotating hypercube with texts attached to each face? (gif attached)

I Think you can do it with bones:

Create a cube, give it this inner geometry (I've hidden the 6 outer faces):

Create an armature with one bone by horizontal face. Parent the cube With Empty Groups to the armature, it automatically create as many vertex groups as bones, assign each face to the vertex group that has the name of the bone that is supposed to move it:

Move and scale the bones so that they follow what happens in your video:

and so on... which gives:

For the image texture, you need to create an image with 20 squares, each with its text, then select your object in Edit mode, unwrap with the Smart UV Project option, in the UV Editor, select all and UV > Pack Islands, then rearrange all the UV islands so that they match the squares.


Revert to default scale when seed changed?

Your approach doesn't explicitly set the scale of all objects, some of which might have been scaled to zero at some point, so their scale never reset.

To fix that, generate a list that define the state of each object, then use that list to control the scale of objects in whichever way you want. It is clear to me that you want to control how many objects gets scaled to zero, so to implement that, we are going to generate a list that has a certain number of zeros, with ones for the rest of the list, such list can be generated using the Fill List node. To make sure it is randomized, we can shuffle it or shuffle the object list itself as follows:


how to animate camera zooming and FOV keyframes

Inside the properties for the camera is a value for Focal Length

If you hover over the value and hit 'I' on your keyboard, you will create a keyframe for that value - at that frame.


How to append bones to a list in a branching manner

Use recursion

import bpy

def walk_bones(bone):
    yield(bone)
    for b in bone.children:
        yield from walk_bones(b)

ob = bpy.context.object
arm = ob.data
rootbones = [b for b in arm.bones if not b.parent]

for rb in rootbones:
    for b in walk_bones(rb):
        print(b.name)

Adjusting slightly to

def walk_bones(bone, level=0, sp="  "):
    yield(f"{sp * level}{bone.name}")
    for b in bone.children:
        yield from walk_bones(b, level + 1)

Can print out the hierarchy, as an example the rigify shark meta-rig

spine
  spine.001
    spine.002
      spine.003
        spine.008
          spine.004
            spine.005
              spine.006
                spine.007
                  eye.L
                  eye.R
                  jaw.master
                    jaw
                      jaw.001
                    jaw.002.L
                      jaw.003.L
                    jaw.002.R
                      jaw.003.R
              shoulder.L
                side_fin.L
                  side_fin.L.001
              shoulder.R
                side_fin.R
                  side_fin.R.001
            top_fin
              top_fin.001
          chest_fin.Bot.L
          chest_fin.Bot.R
    mid_fin.Top
    mid_fin.Bot
  back_fin.T.Bk
    back_fin.T.001.Bk
      back_fin.T.002.Bk
  back_fin.B.Bk
    back_fin.B.001.Bk


I can't seem to sync the audio and video!

A video strip is a sequence of still images, the time it takes to play them is determined by the number of frames played per second. The closest an audio clip has to fps is samples per second, so is always played based on a time measurement.

By changing the frame rate setting in the render settings, you vary the length of time the video strip takes to playback but not the audio, to keep the video and audio in sync you need to have the frame rate match the original video settings.

The easiest way to know that the frame rate is wrong is in the sequencer, the video and audio strips will only be the same length if the frame rate is correct.

To get the audio in sync with the video, set the correct frame rate. If the video stops early that means you need to increase the end frame to match the length of the video.

When you add a video strip to the sequencer there is a Use Movie Framerate option that will set the frame rate to match the video for you but you will still need to set the desired end frame.


It appears that you have enabled show weights under mesh display.

You can disable this in the properties panel while in edit mode by pressing N to open the properties panel, and locating Mesh Display and then unchecking the option.

Other blue lines can also be caused by having the sharp box ticked. Uncheck this if necessary too.


Pinning cloth to animated model is making cloth go crazy

There are few things that seem to be causing this.

The main thing was that the legs had a largish outer collision margin which was causing the robe to collide constantly.

Try changing this to something like .004 on both legs:

Also try making the skirt bigger initially. There has to be room for the legs to move ;)

Result:

I also pinned the entire top edge loop instead of just the corner vertices, reduced the collision quality to about 3 and disabled self collision. These massively decreased the bake time without a lot of visual impact once the collision issue was fixed.


Why is Blend4web's 'pick_object' giving a 'null' value?

the object must have Selectable option enabled in its Blender settings.


Unwrapping sphere in order to fit this image

We can unwrap the sphere same as a cube, if the geometry of sphere is just subdivided and displaced cube:

Create a cube and give it these modifiers:

Proceed same as with unwrapping a cube. The texture can look like this:

Notice the bleeding over the unwrapped mesh. That is to not pollute the surface with green (or black in my example). You can also pack those faces much more efficiently if you like, to not waste any texture space:


It strikes me as a two point lighting setup, where both lights are slightly behind the model giving the front a heavy shadow.  This is a top-down view of my sample scene.

I couldn't get anywhere close with a material until I started messing around with some very strange SSS values.

My world lighting doesn't match the reference, and it may have been taken into the compositor for some color correction.


bmesh script.

Add sphere, remove only faces with bmesh in object mode

import bpy
import bmesh

context = bpy.context

bpy.ops.mesh.primitive_uv_sphere_add()
ob = context.object
me = ob.data
bm = bmesh.new()
bm.from_mesh(me)
bmesh.ops.delete(bm, geom=bm.faces, context='FACES_ONLY')
bm.to_mesh(me)
me.update()


Option 1 (Transfer UVs)
Use the Data Transfer modifier, and select "UVs" under "Face Corner Data". Make sure you click "Generate Data Layers" so it has somewhere to put the transferred coordinates, and play around with the mapping type to find the best result.
Pro:

Allows re-using the same texture map(s).

Con:

Cannot automatically handle seams.

Option 2 (New UVs, Transfer Texture)
Unwrap the re-meshed model separately, and use Render Baking in Cycles, for "Diffuse" colour and with "Selected to Active", to transfer your original model's textures to the remeshed geometry's new UVs.
Pro:

Allows precision down to pixel scale.

Con:

Requires texture duplication, inefficient and lossy.


Why can't I see my object when I start the game engine?

Make sure it's not invisible in physics.

Make sure the normals are facing the correct direction.


Radius is different even though mean radius is the same on beveled curve

For a single vertex, you can edit it inside the Menu>Item>Transform>Radius;
but for several at once, it seems impossible at the moment.


get worldOrientation as the target of other objects

It's unclear if you mean the object's position (worldPosition) or orientation (worldOrientation).

Either way you can get smooth change of orientation by using bge game object function alignAxisToVector(vect, axis, factor). As vector, input the other gameobject's corresponding vector (like positive X-axis) and as the factor using a small number like 0.1 to make the transition smooth. https://www.blender.org/api/blender_python_api_2_77_0/bge.types.KX_GameObject.html?highlight=alignaxis#bge.types.KX_GameObject.alignAxisToVect

You can get smooth change of position by first getting the delta vector between the objects and then adding only a small factor like 0.05 of it to your objects position every frame.


Is there a way to rotate the axes themselves?

Yes, if one fits your needs you can use a different transform orientation. If not, you can create a custom one.
Other transform orientation systems can be selected in 3D view > Header > Transform orientation:

Note that to transform a selection along the orientation set in 3D view > Header, you need to press the axis key twice, e.g. RYY. Otherwise Global coordinates will be used)
View
The orientation for the View setting is controlled by the angle of the view. See the wiki:

The manipulator will match the 3D view, Y → Up/Down, X → Left/Right, Z → Towards/Away from you.
This way you can constrain movement to one View axis with GXX.

You could use two 3D views, one to define the transform orientation, and another to actually view and interact with the scene.
Local
You could also try using local coordinates, which is defined by the rotation of the selected object(s). See the wiki:

The manipulator matches the object axis. Notice that, here, the
Manipulator is at a slight tilt (it is most visible on the object's
y-axis, the green arrow). This is due to our 15º rotation of the
object. This demonstrates the difference between local coordinates and
global coordinates. If we had rotated the object 90º along its x-axis,
we would see that the object's "Up" is the world's "Forward" -- or the
object's z-axis would now be the world's y-axis. This orientation has
an effect on many parts of the interface, so it is important to
understand the distinction.

Custom
You can also define arbitrary custom orientations based on the orientation of existing geometry, see my answer here.


Render slows down in the last couple minutes

Everything is just simple.

i5-4670k heve 8 logical cores wich one by one render slower that one GPU.

Can see, how GPU overtaking CPU cores. And then they remain, but the GPU is not involved in process. There is also an inaccuracy in the calculation of time.

It would be better if the CPU represented only one tile. I have posted about it on developer.blender.org.

You need to render only by GPU and it will become faster then with CPU.


I had accidentally applied the glass material to the inner eye as well as the outer eye. It was dark because there was nothing for the light to bounce off. It looks much better now.


The problem can stem from applying scale to the lattice. You shouldn't do it. Apply scale to a chair, create new lattice for the leg and don't apply scale to it. Then this setup should work perfectly, but I would suggest to subdivide the leg little more to get the effect, you need.
Also in my opinion it would be easier to just use proportional editing directly on the leg vertices to get desired curvature. Lattice doesn't give more control in this particular example.
I would also suggest you to split the chair on 2 and use mirror modifier to ensure, that bending will be exactly the same for both legs.


It looks like all four of your faces have more than four vertices, perhaps because of duplicate vertices. Do eliminate these, in edit mode, press "W > remove doubles". If this is not it, then it's likely that the four faces marked for unwrapping are n-gons. The likelihood is that the faces with the off center face selection dots are the offenders.


Need an practical method to model this bike wheel

The principle can be around this:

We are in top view here, there is a mirror modifier along Z and a subdivision surface:

From left to right:

Add a circle with 6 edges. Shift it a bit along Z (for the mirror and rim thickness).

Extrude all and scale down ES.

Rotate the center part.

Select all the faces and inset I.

Extrude along Z E to the mirror center.

Delete the faces X, faces only.

This is only an approach. Of course you need to work a bit more to make it accurate to the picture.


You can basically dismiss all, except modeling riging/animation and UV mapping.
You won't transfer to unity nothing except that (no camera, no lights). If for material you are using only diffuse with textures (color, normal) it'll transfer well. Only thing to remember is to import to the project textures first and then import .blend or exported .fbx.


How can a path animation be used as an action in the game engine?

You can convert actions such as constraints to keyframes with Object > Animation > Bake action. (see this)

You may want to enable Clear parents to replace parent/child with keyframes:

Also note that without Clear Constraints enabled, constraints will not be removed, possibly giving unexpected results.


Failing to chisel (boolean difference) text on a cube side

Try adding a remesh modifier to the text:

Then the boolean modifier will work as expected:


Mirroring to start Symmetry - object doesnt flip

There are a couple of ways to mirror an object in Blender:

Mirror Mofifier

This is an undestructive method to mirror your object with the most control. Go to the object's modifier panel and add a mirror modifier:

(Blender doc: https://docs.blender.org/manual/en/latest/modeling/modifiers/generate/mirror.html)

Edit Mode Mirror

Go into Edit Mode, and press 'CTRL+M' or in the menu go Mesh>Mirror>Desired Axis

This is a destructive but direct solution to mirror your object.

(Blender doc: https://docs.blender.org/manual/en/latest/modeling/meshes/editing/transform/mirror.html#mirror)


You need to connect your Normal Map image texture through a Normal Map Node before connecting it to the Principled BSDF. Also, change the color space of your Normal Map image texture from sRGB to Non-Color:


Smooth shading averages the normals on the model. It approximates the smoothness of the surface on any geometry that is actually not smooth so it is indeed possible to have geometry that looks completely wrong with smooth shading because there is just not enough of it to look smooth.

You should expect smooth shading not to look OK on any sharp corners/edges. If you want the model to look smooth, you should not smooth those corners and edges for example using Auto Smooth and it's Angle parameter:

Or you could bevel the edges as well to provide adequate amount of geometry for the smooth shading.

You might also want the Normals to be averaged in a way that would take face areas into account so flat parts of your model look correctly and in 2.80 you can now use the Weighted Normal modifier with Weighting Mode set to Face Area:

In previous versions Blender did not have such a functionality natively and an add-on such as Yet Another Vertex Normal Editor (Y.A.V.N.E.) had to be used for this.

Messy and untidy geometry with overlaping elements or non-manifold geometry will cause issues like that as well, this is why it's called untidy or messy. You should avoid concave polygons, n-gons, overlaping geometry, non-manifold geometry, double vertices and things like that to avoid theese problems with shading as well.


Is it possible to save the Euler rotations as Quaternions without loss of data?

In 2.79 there's an addon that works very well, called Quat/Euler rotation mode converter.


how to Unstretch Material on Object on 2.8?

If you like to control the texture using the UV's you should change the 'Texture Coordinate' node to UV instead of GENERATED.


Is it possible to set the Output name based on the current Timeline marker?

Following script renders every frame in the timeline if it is a marker assigned to it. It uses the existing output file path and and the current marker name as output file name.

import bpy
import os

# get the scene
scn = bpy.context.scene

# get the output path
output_path = scn.render.filepath

# iterate through markers and render
for k, m in scn.timeline_markers.items():
    frame = m.frame
    marker_name = m.name
    scn.frame_set(frame)
    scn.render.filepath = os.path.join(output_path, marker_name + ".jpg")
    bpy.ops.render.render( write_still=True )

bpy.context.scene.render.filepath = output_path

.blend