Difference between using VSE and direct output as video?

Difference is huge!

Imagine you have animation of 2000+ frames long and you outputing it straight as HD video. Let's say at frame 1900 electricity went down or another PC problem occured - it will ruin all rendering! Output file will be corrupted and useless.

Now think about Image sequence + VSE combination, if everything went wrong during rendering - you still have 1900 frames ready, so nothing to worry about. This is very simple case, but there are much more advantages of image sequence output (like distributed rendering on several PC's, re-rendering minor oversights and others).

Straight to video might be usefull for quick OpenGL viewport preview or low-res renders, where actual rendering process takes about 1-10 seconds for a frame.


Workaround for 'Inherit Rotation' in armature?

I can't tell you how to solve your problem but I think I can tell you about the helper bone.

Long time ago I implemented a bvh importer for another software (not blender), to get it working with the rotations given in the bvh file I had to add an helper bone for each existing bone.

A zero length bone (no influence to the mesh) placed at the origin of the original bone, and obviously the original bone must be parented with the helper (original child, helper parent), all the rotations are applied to the helper only.


Does anyone know how to make scripts appear on the left?

You have to split the area and change the window type to the Scripts Window or Text Editor, depending whether you want to execute a script/add-on shipped with Blender or open the actual source code.

Place the cursor on the border between two windows, e.g. the 3D View and the User Preferences.
Right click and select Split Area.

Change the window type to Scripts Window for executing a script/add-on or Text Editor to load the source code of a script or write your own.

Scripts can also be executed from the text editor through Text > Run Python Script.


Don't use SLI (Scalable Link Interface)

SLI works by linking two or more video cards together to produce a single output, which works to speed up the display in games.

Cycles works better if the load is split using each GPU independently.

Using the Nvidia Control panel you can disable the use of SLI.


How do i display the Lengths of an object in 2.8

In Edit Mode, press the little arrow at the top of the window to show the Viewport Overlays.

Under Measurement in the menu that opens, enable "edge length.


You need to find the right path to the data you are looking for, using the python tooltips in blender can help here, they are enabled by default but if they have been turned off you can enable them in preferences. Searching through blenders python api online can also help.

First let's clarify your use case, you are setting plane.game.physics_type so you may want to set the matching plane.game.mass both of which are only relevant for the game engine physics.

If you are using the interactive physics available in the 3Dviewport then you will want to use plane.rigid_body.type and plane.rigid_body.mass


Some ideas:

Frame X-1: set the object position outside the screen, Frame X: move the object into the screen
Use an emitter to emit the parts (with the number of emissions you can control the frequency of emission) (see image 1)
You can have all the objects invisible and animate the visibility in the timeline using the shader

image 1:


How to make smooth edge of box with materials?

Why not do this with textures?

Simply make a black-and-white image texture, and use it to switch between two different material node layouts. It'll be better for performance as well, because there's fewer faces.


Not exactly realtime but hitting Tab twice (goes into edit and back) after a stroke of texture painting will update the geometry right away.


Is there a way to make a ball bounce endlesly? (using soft body and physics)

Basically prepare your physics simulation as you like, bake the frames, and apply cycles modifier in the graph editor


As far as I can deduce, Blender is just about following Pixar's creasing rules, so there's one more to add to moonboots' magnificent collection:

keep your original topology, but crease the diagonals as well.


In version 2.8x Alt+Click is gone.

The way to select a loop is by double clicking.


enable-autoexec option not working in ubuntu blender

As explained here, the --python cli option will bypass the settings, allowing a script to alter the setting. You can set it in python with

bpy.context.user_preferences.system.use_scripts_auto_execute = True

Another way of setting preferences is the userpref.blend file. You can save one on your machine then copy it to your remote server. There are several places blender looks for the userpref.blend - LOCAL, USER, SYSTEM - in that order. If you manually install a pre-built copy then you can add your userpref.blend into the local folder which would be 2.76/config/userpref.blend next to blender itself. More likely you will want to add it to your home folder ~/.config/blender/2.76/config/userpref.blend If that fails you can also set environment variables with the paths to look for certain files.


Procedural chain links not working with blender curves

Curve Modifier
With origins of both objects at the same place it seems to be working properly.


Why does my normal map have grey squares on it

I figured the problem out. For some reason, removing the translucency map from the grip tape texture solved the problem.


This doesn't help you analyze your texture, but it'll at least get you projecting it on the sphere.

Add a UV-Sphere to your scene

Switch to front-view (1) and set camera view Ctrl+Alt+0

In edit mode, use box-select (B) to select the vertices visible from the front, then UV-Unwrap, selecting "Project From View"

In the UV/Image Editor window with your vertices still selected, open one of your images and scale the UV-unwrapped mesh to fit

Add a material to your sphere, using your image sequence

Switch to rendered view, and see your image projected onto the sphere


Cropping two perpendicular curves at their intersections

You can achieve this result by using the Boolean modifier.

Select your large curved mesh, and add a Boolean modifier set to Difference.

This will make the curved wall follow the contours of the arch in the direction of the Normals. You may need to re-calculate them (Ctrl+N) to get the desired result.

Now if you apply the modifier, you can remove the arch mesh and you should end up with a completed single mesh with the desired arch shape in it.


Can Blender show edges of lo-res mesh on hi-res mesh when editing subdiv surface?

Press the fourth icon next to the subdivision surface name (Triangular Polygon).

The tooltip is Adjust edit cage to modifier result.

Note that while you will be seeing a displaced vertice, the editing operation still act on the original vertices with their respective locations.


Why can't I make a vertical loop cut on this object?

To answer my own question. There were hidden doubles in the object. Even though the original post says that this was already checked, I removed doubles again and that time it worked.

In edit mode I deselected, then reselected all and used the remove doubles tool.
A, W, Remove Doubles.

Making sure to set my Merge Distance greater than 0. After that, I was able to add a vertical loop cut.

The other SE questions I used to help fix this were:

why does loop-cut-and-slide ignore some faces but not others?
Loop-cut won't go all the way around
Loop cut interrupted


Python API: Transformation from `Bone` bind pose to `PoseBone` using SQT

using quaternion for rotation does prevent gimbal lock, see Why are quaternions used for rotations?

Use it to set the rotation part of your final matrix at time t. See mathutils for conversion


Wrangler plugin not working (Known bug with the 2.83 build)

Most likely issue is that you don't have node wrangler enabled.

How to enable it is by going to

Preferences

Then to addons

Then search for node wrangler and press the check box beside it.


Blender how to periodically reload file (python)

Quote from the api documentation

  Python threading with Blender only works properly when the threads finish up before the script does

There are two ways i know of to periodically run python code:

Register a handler for scene_update_post:

import bpy
import time

t = [0.0] * 3
t[0] = time.time()
handles = bpy.app.handlers.scene_update_post

@persistent
def on_scene_update(scene):
    t[1] = time.time()
    t[2]+= t[1] - t[0]
    t[0] = t[1]
    print("Time elapsed %f" % t[2])

    if t[2] > 20.0:
        handles.remove(on_scene_update)

handles.append(on_scene_update)

Use a modal operator (in this case the code only runs when the user interacts with blender):

import bpy
import time

class OT_INFO_time_elapsed(bpy.types.Operator):
    bl_idname = "info.time_elapsed"
    bl_label = "Print elapsed time to the console"
    bl_options = set()

    def invoke(self, context, event):
        self.current = time.time()
        self.prev = self.current
        self.elapsed = 0.0
        context.window_manager.modal_handler_add(self)
        return {'RUNNING_MODAL'}

    def modal(self, context, event):
        self.current = time.time()
        self.elapsed += self.current - self.prev
        self.prev = self.current
        print("Time elapsed: %f" % self.elapsed)
        return {'PASS_THROUGH'}

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

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

if __name__ == "__main__":
    register()

Since you intend to reload the file only the handler using the @persistent decorator will work.


First, make sure Blender is using the same resolution as your input video in the timeline.

If you're still slow, then it's probably time to generate proxy files. You're probably trying to edit a compressed video type instead of a RAW video type. By making proxy files, you get around this issue.

Here's a video tutorial on how to generate proxy files.


This is the overview. I am breaking up the parts into individual answers that we can link to from other questions. This is a community wiki, so feel free to add ones that need to be addressed completely in another answer. If you decide to add another answer, please follow the pattern that I used with the first individual answer. This will make it easy to send people to this question or a particular answer while knowing that their question will be answered completely.
Invisible to the render

Camera icon is disabled in the outliner

Render layer not showing in the compositor

Render layer does not include scene layer or the objects are in a layer that is not renderable.

Scene layer not selected

Cycles camera visibility disabled in object settings

Cycles material disables visibility to the camera

Objects are not within the range set by the camera clipping

Using the wrong scene

Strips present in the VSE, and the sequencer box is enabled in the post process section

Cycles: Exposure setting in the film section set to 0

Depth of field not set properly making the whole scene blurry

Object blocking the camera view

An object has been set as the active camera.

There are no lights on the scene or they are on a different layer.

Objects have no faces

The Solidify modifier takes over the object and is disabled in Viewport

Duplication type set to 'Group' and no group is selected.

Duplication issues (under the Object tab in the properties panel), e.g., duplication type is not 'None', and object has no childen, or set to 'Group' and no group is selected.

Render layer In Node editor is muted (disabled)

Cycles materials don't have a shader node

Camera is not pointed at object

Save your data to .blend before rendering with Cycles/Eevee (Blender 2.8)

Object has a particle system with emitter visibility disabled and/or no particles

Cycles Filter is active

Invisible in the viewport

Object is hidden
3D view clipping distance set too high/low
Scene layer not selected
Using the wrong scene
Object is moved far away
Using local view
View Border is active (Alt+B)
Cycles Filter is active (same as #24 for the "render" list above)

Note: I will be adding reference images, details, and links as time allows. Hopefully this will be helpful to someone. If you think of something that I missed, feel free to suggest an edit.

Questions about problems that have not yet been addressed
Why Does My Object Not Show in Rendered Shading Mode?
Why do some objects not show up in the camera view?


How to enable ambient occlusion with python?

To turn Ambient Occlusion on you must set its value to True. What you are doing wrong is that you are trying to execute the function use_ambient_occlusion() which does not exist because it's variable not a function.

import bpy
bpy.context.scene.world.light_settings.use_ambient_occlusion = True  # turn AO on
bpy.context.scene.world.light_settings.ao_factor = 0.5  # set it to 0.5


Bezier freehand draw curve is very coarse with larger errors

Looks like this is a small bug perhaps, I closed blender and restarted and it is no longer a problem.


You should either define a vertex group on your sphere and change the particle settings (also for your fire and smoke) to limit emission to that vertex group or, seeing that you seem to be using this sphere for nothing else, simply delete the parts of the mesh that should not emit particles or smoke.

Quick explanation of vertex group approach:

Select your mesh,
go into Edit mode,
then select the vertices/faces that you want to emit particles/smoke,
then go to the object data tab and create a new vertex group by clicking the "+"-button in that area. You should give the  group a meaningful name.
Then click the "Assign"-button beneath the list of vertex groups while your new group is selected and the selected vertices will be assigned to that group with a weight of 1.0.
Next, go to the particle settings under Vertex Groups and select your new group for the Density setting.
For smoke, look at the Smoke Flow Advanced section of the emitter object's smoke settings. You can select the vertex group there.


Dramatic changes in performance depending on selection

Blender selection drawing method is notoriously slow. This well known among the devs and a known limitation of the current system.

Basically highlighting the selection outline doubles the required processing power of regular viewport drawing, yielding almost half the FPS.

Unless you plan on rewritting a whole viewport rendering engine code youself, or a new OpenGL realtime renderer there is not much one can do at the moment, as far as I know, other than await the 2.8 release and its modernized real time rendering based on EEVEE engine.

One possible workaround for the time being is turning off selection highlighting in the * 3D View Properties Region > Display > Outline Selected*, though it is not without its downsides. You won't really know what is currently selected or which is the active object while turned off.


How can I get the music file to play in the final animated version?

Try enabling the audio codec located under the render tab:


How to show Blender thumbnails in Linux (Ubuntu)

Save this file to: $HOME/.local/share/thumbnailers/blender.thumbnailer

[Thumbnailer Entry]
TryExec=blender-thumbnailer.py
Exec=blender-thumbnailer.py %u %o
MimeType=application/x-blender;

If you install Blender via Ubuntu's package manager, blender-thumbnailer.py will be in your PATH, otherwise you'll need to add it.

From what I can tell, you need to have blender-thumbnailer.py in your PATH for this to work.

See: How can I edit the $PATH on linux?

Note, it would be good to see if this could be simplified or even done automatically.


Why are some items not showing up in my rendered animation?

When I open your file and play back the animation (by pressing [Alt+A]) the Ts do not move at all. They hang above the camera and never come into the picture, thus they never show up in your render.
I am not sure why the animation behaves like this, but I have found a way to resolve the problem: Set the Start frame of your animation to 1 and let it play once. The rigid bodies will fall down from their starting position. When you set it back to 250 afterwards, the Ts will behave correctly and fall down.

Edit: It looks like Blender is caching the animation. See the orange line at the bottom of the Timeline:

The part that is cached is colored in a strong orange, the uncached part is only slightly orange. I think this cache is temporary and is lost when you close blender. If you start your animation again from a point that is not the beginning, Blender does not know the current velocities / angular velocities of the rigid bodies and could not solve the rigid body motion correctly, so it shows no motion at all instead.


The reason this happens is because you have animation information on the armature that you are painting to, the mesh updates to that information once it is painted to a certain bone.

This can be desirable if you have a certain pose that you do not know how it will deform the mesh, and you can weight paint until the mesh looks fine in the tricky position. However, this isn't the case, and we'll need to solve it.

Switch into pose mode. (Ctrl+Tab) now, hit A once or twice (depending) to select all of the bones. Alt+R will clear all rotation data, and likewise, Alt+G will clear translation data.

You may now weight paint without any mesh deformation.


Where is the "average" setting in the vector math node?

Blender automatically converts old nodes when copied into newer versions.
So Average becomes Add + Normalize


How do I change material render preview?

Had the same question found your then just worked it out by pick things.
Top right hand corner of the 3D viewport there is a drop down arrow.
In viewport shading you can select scene lights and scene world.
I didn't try to see if this would give you the result your looking for but it has worked for me.
Regards


How would I texture this lamp, especially the lamp shade?

It's Surprisingly simple. Just an image texture, for the pattern (like this one) and a Translucent BSDF node.  The trick is to put a lamp inside the shade (where the light bulb would go in real life.)

The layer weight node is how I made the darker edges. The RGB Curves node, inverts and changes the slope of the fresnel. Then the ColorRamp node is just to tone down the black (I'm using 0.05, instead of pure black).
The bottom three nodes are just the standard image texture nodes. The shade texture (a black and white image) get multiplied with the fresnel, and all that is plugged into the Translucent node. Next trick is the Mix Shader node with an empty socket. That is just making the whole material darker.


How to set edge bevel weights from a python script

There is no custom data layer for edge bevel weights by default. You need to explicitly enable it (this is done automatically if you use the Edge Bevel Weight modal operator in the UI):

ob = bpy.context.object
me = ob.data
me.use_customdata_edge_bevel = True

Furthermore, the mesh needs to be in Object Mode when you apply a bevel weight:

if ob.is_editmode:
    bpy.ops.object.mode_set(mode='OBJECT')
me.edges[0].bevel_weight = 0.7

If you want to avoid mode switching, you may use the bmesh module instead (bm.edges.layers.bevel_weight).


How to make this cube texture node programmatically

If you mean a procedural texture, here goes...
This tree is based on 2 node-groups:
A 'Hexagonal Grid', as discussed here:

Which produces a hexagonal grid of cells, each with their own UV coordinates, on the left, below:

And a 'Distance to Hexagon' group:

which takes the maximum of the shading-point's local X and its projection onto a diagonal edge, all reflected in X and Y. When put through a threshold, it produces the edges in the middle image, above. If you use the whole set-up twice, once offset by sqrt(3)/3 in Y, then you get the cube-illusion on the right.
For the hatching, the same cell-UV coordinates are used to place a Gradient > Radial texture in each cell of one of the overlapping hex grids, and it is stepped off into thirds with a Snap node, into sections valued 0, 1/3, and 2/3. (Left, below).

The values in those regions can be used to rotate a thresholded Wave > Bands texture, to produce the directional hatching (middle, above), and combined with the outlines to give the result (above right):
The whole tree is a bit big to show conveniently, sorry:

The result:


If you use video as reference, best way to do this - using image empty.

Image empty always shows current frame; over methods, that i'm tried gives +-1 frame offset. To add image empty press Shift+A -> Empty -> Image


Set the Z translation to 0 instead of -0.5 in the mapping node. What you are seeing here is a cross-section along the bottom of the sphere gradient, instead of the middle cross-section.

Illustration :


Can you auto-pack a selected group of islands in UV view?

Use Pack Islands command to automatically organize all your islands so that they fill the UV space:

  The Pack Islands tool will uniformly scale, then individually transform each Island so that they fill up the UV space as much as possible.


Export an animated 3D model to Power Point

Take a look at here for a quick overview and at the 3D Content Guidelines for Microsoft powerpoint for details.  As the 3D engine in Powerpoint is now based off Babylon.js GLTF format is your best bet to get content to import correctly.


Simulated hair isn't affected by force fields?

I noticed two issues with the wind forces, they are quite weak and they are facing the wrong direction.

The affected axis (under Falloff, next to Power) was set to -Z (in local coordinates), but the force fields have their positive Z arrows pointing towards the object.

Increase the strength and set the axis to +Z:


Use graph editor for simulate neons flickering, curves don't match perfectly and negatives values of light absorbe light from the ambient

You can add a Limits modifier to clamp the output to any range you want.
The limits modifier can be added from the N panel in the graph editor.


Blue sharp lines didn't just appear-- you did something to make them appear.  But, they were probably always there.  Probably, because you imported this mesh using a function that marked edges containing custom, per-face normals as sharp edges.
The solution?  If you were happy with your normals before you cleared sharp edges, but not after?  Roll back to just before you cleared sharp edges.  Or else, remark those edges as sharp, if you remember which edges they were.


Mapping node animation does not work in Blender Internal!

Well, I found a workaround:

Instead of animating the mapping node I animate a blue value in a combine RGB node. It is possible because Blender converts RGB colors to XYZ coordinates automatically.


What is the fastest and easiest way to add a vignette in the compositer for Cycles?

I usually do something like this:

It doesn't take too long to setup (three nodes), and it's provides a high degree of control:

The aspect (or even rotation) can be controlled via the settings of the Ellipse Mask* node.
The softness can be controlled with the Blur node
The amount of influence can be controlled via the mix node factor.

For a more automated solution
You could try something like this (click for full size):

This can be grouped into a single node (and included in your startup file) with very simple controls:


Although the expression is one line you can call a complex function in that line, you have to define and add this function to the driver's namespace before using it.

here's an example function and how it's added to the Driver's namespace ( from the DOC ) :

import bpy

def driverFunc(val):

    return val * val    # return val squared

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

To see the already availabe functions and properties type bpy.app.driver_namespace[' in the python console and hit Ctrl+space

DOC link for more info


How do I model from a side view with a reference image?

You need to use background images either in orthographic view, or using stationary camera views rather than planes. Background images is in the properties window on the right hand side when you're in 3D view (you can toggle its view with the "n" key). from there you can load up images, and choose which views they are visible from. all views except for camera view are only visible in orthographic mode which is the view when you press 5 on the num pad and then press 1, 3, or 7 to see front, side, or top views. since things are not orthographic in real life you can also use a camera view background image to keep the reference image stationary against the  model.


Changing Materials On Multiple Copies Of Same Object (within cycles)

You can use the Random output of the object info node to get random values between 1 and 0 that are unique to each object with the material. You can use this to change the color of an object using a color ramp node:

However, this only works for objects (you convert your particle system to objects with CtrlA> Make Duplicates Real, but they will no longer be animated).

You can kind of do the same thing for particles with the index output of the Particle info node (dividing it by the number of particles), however the output will not be random; the first particle will have a value of 0 and the last will have a value of 1.

If your particles move around and get mixed up enough, it may not be noticeable, especially if you chop up the color ramp node:


You need to activate another add-on: Add-ons->Edit Mesh Tools.
How I understand Relax add-on include in Edit Mesh Tools add-on. This problem was discussed at the bug tracker.
Though the official manual tells us another information:
https://docs.blender.org/manual/en/latest/addons/mesh/edit_mesh_tools.html#
https://docs.blender.org/manual/en/latest/addons/mesh/relax.html
Maybe the developers didn't correct information in the manual.


Add uv_layer to mesh, add uv-coords, with python

As Dragonseel mentioned: the bmesh is important.  http://web.purplefrog.com/~thoth/blender/python-cookbook/barber-pole.html contains a spiralUVs function which assigns UV coordinates to the faces of a cylinder.  It demonstrates the mesh.uv_textures.new(name) function for creating a new UV layer.

Here is the function from that page:

def spiralUVs(mesh, xPlus):
    # add a UV layer called "spiral" and make it slanted.
    mesh.uv_textures.new("spiral")
    bm = bmesh.new()
    bm.from_mesh(mesh)

    uv_layer = bm.loops.layers.uv[0]

    nFaces = len(bm.faces)
    for fi in range(nFaces):
        x0 = fi*2/nFaces
        x1 = (fi+1)*2/nFaces
        bm.faces[fi].loops[0][uv_layer].uv = (x0, 0)
        bm.faces[fi].loops[1][uv_layer].uv = (x1, 0)
        bm.faces[fi].loops[2][uv_layer].uv = (xPlus+x1, 1)
        bm.faces[fi].loops[3][uv_layer].uv = (xPlus+x0, 1)
    bm.to_mesh(mesh)


How can I print the string of a parameter from a property?

Yes. Once registered you can use bl_rna.properties to access the name, its type, the items, the description etc... I'd suggest use the python console to test:
>>> test_items = [
...     ("RED", "Red", "", 1),
...     ("GREEN", "Green", "", 2),
...     ("BLUE", "Blue", "", 3),
...     ("YELLOW", "Yellow", "", 4),
... ]

>>> bpy.types.Scene.my_enum = bpy.props.EnumProperty(name="Foo", items=test_items)
>>> bpy.types.Scene.bl_rna.properties['my_enum'].name
'Foo'
>>> bpy.types.Scene.bl_rna.properties['my_enum'].enum_items[0]
<bpy_struct, EnumPropertyItem("RED")>
>>> bpy.types.Scene.bl_rna.properties['my_enum'].enum_items[0].name
'Red'

In case of an operator property, I'd suggest read the values from the operators annotation dict:
class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"

    my_prop: bpy.props.StringProperty(name="foo")

    def execute(self, context):

        # via bl_rna
        print (self.properties.bl_rna.properties['my_prop'].name)

        # using annotations
        print (self.__annotations__.items())
        print (self.__annotations__['my_prop'][1]['name'])

        return {'FINISHED'}


Where are the many tris located in this model?

I have found out that there's a subsurface modifier attached to the model.

When I delete it, the tris go down to what I see.


Create a new shapekey for your plane.  Enter edit mode on that shapekey.

Use transform->randomize operation.

Use a triangulate faces operation.  In operator panel, specify "shortest diagonal."

Leave edit mode and delete your shapekey.


So i found the problem. make sure your delta transforms are normal


Repurposing vector (speed) render layer for optical flow

Found the solution.
The trick is to enable the desired render layer (ie "vector") and then save the render output as OpenEXR file. That format will save all the desired render layers (in this case, motion information in 4 channels) in a single file, which could then be accessed through various interfaces like Python and Matlab.


EEVEE:

This is as soft as you could possibly get with EEVEE.
Unfortunately softness is "hard coded" so you can't change lamp distance to have more/less softness.
I have used the same method as you - Spot Lamp enclosed in a Cube. I've also parented Lamp to the Cube just to make ability to move/rotate them nicely.
Lamp settings:
Basically this are the only settings that have influence over the lamp softness. Not much to play with:

Softness to the max - 100, Bias to the minimum - 0.001 and Exponent is a matter of taste.
There is not much to explain here, but if you have more questions feel free to ask in comments.


Old question. I'm using Blender 2.79, but I had the same issue. I also didn't realize IvyGen comes pre-installed with blender; and after installing it I got this issue.

Blender doesn't overwrite plugins (at least this version - I can't vouch for 2.77, but I'd doubt it). Instead, it stores plugins in the AppData directory. I got this error, which clarifies:

After deleting the copy of the plugin from my AppData, then restarting Blender, I'm able to enable the correct copy of the plugin, and it now runs fine.

Note that, adding an ivy curve to a Blender default startup file with a cube may not appear to work immediately. This happened to me because my cursor was inside the cube, since the ivy (as when any other objects are added via Shift+A) grows from the 3D cursor's location.


I believe it's a problem on normals. Visualizing the Normals at the [Properties Region] -> [Mesh Displays] revealed some peculiar normals.

At the same time, recalculation didn't work properly showing that you have topologically wrong faces. (Actually I found some but it's too tedious to name them. Add comment if you cannot find any)

Hope it helps.


Reflection on an semi-transparent object

As I understand it you are trying to illustrate a spherical camera using reflection on a sphere. But your main problem is that the reflection is relative to the position of your (the viewer) perspective.

As you rotate around your sphere, to eventually seeing the backside of it, the reflection of the square gets distorted. For example, in the image below (fig 1) I have positioned a NURBS path to go from the center of the cube to the center of the reflection on the sphere.
Yet as we move around the workspace, we see that the distortion causes the reflection to change its position on the sphere (fig 2):

If you wish for the "reflections" (if we can even call it that at this point) to be mapped to the sphere regardless of camera position, then you need baking. (animated gif):

How I accomplished this:

First I set up my scene: added a background, the sphere, some props from the archimesh addon and a cube with black lines around it.
I selected the sphere and went into edit mode, turned on orthographic mode, and snapped to front view via numpad-1.
I unwrapped the sphere using "sphere projection" (u key) and opened the node editor and the uv/image editor.
I created a new "blank image" in the image viewer, and set up the material for the sphere, like so: Note how the Image node is not connected. It is also important that the image node uses the new blank image, and that the image node is the selected node.
With the sphere selected I go to the render panel, under "bake", select "glossy" and click the bake button:

As you can see in the image editor, the "blank new image" is no longer blank:

Then I reconfigured the sphere material to use the baked image, taking into account the transparency you asked for, etc

After this, it works! However, there are some caveats:

Because it's a baked image, it doesn't work well when the environment around it is changing. To get by this you would have to bake an image sequence of it per frame or take advantage of the equirectangular uv mapping and somehow pipe a camera into its texture (not sure if that's even possible).
It's annoying to have to rebake every time you change something.

Good luck and happy blending!


Use these settings:

Render → Screen Space Reflections - On
Render → Screen Space Reflections → Refraction - On
Material → Surface → Principled BSDF → Transmission - $1.000$
Material → Surface → Principled BSDF → Roughness - Adjust to your needs
Material → Settings → Blend Mode - Opaque
Material → Settings → Screen Space Refraction - ON
Material → Settings → Refraction Depth - Adjust to your needs, I generally suggest $0.8$ but depends on the thickness of the object.

Result:

(It's quite similar to Albert's answer but different)


He is stating that he was inaccurate by mirroring the octave of the sphere in all three axis as on the Y is not symmetrical. This kind of ball, as in tennis and baseball is traditionally made by joining two complementary pieces

This is what you have at the moment:

Notice that the model is symmetrical on all the three axis while in the real traditional basketball (usually) isn't.

What you should see from one side is different from what you have on the other. Here's a pic of the different flows of the leather patches in the front and rear view:

As you can see each patch embrace the other, so one of them must be rotated by 90° from the other to join correctly.

The difference is only in which patch stop at their intersection. One time should be one and vice-versa.

About the tutorial:

What you probably missed is that the Mirror modifier should be applied before following the textual instructions, or you'll not able to edit the geometry.

At the end of the gif it looks as if nothing wasn't changed at all but is just an illusion caused by overlapping geometry: I showed how to perform the instruction only on one of them.


How to move multiple objects in a concentric motion?

One way is to use vertex based instancing of the moving parts on a dodecagon (12-segment mesh circle). Then animate the scale of the circle.

First set a scale limit constraint on your object:


You could emit objects from a vertex group of a ico sphere. Let the emitter follow a curve a force field could follow the emitter and attract all particles. The distance of the force field can be controlled by offset.

The fade out of the trail can be controlled by the particles age e.g.

(Note that the particle count has been lowered in the .blend) The age is not correctly calculated when using child particles.


I am on Blender Version 2.81.11 and everything worked as expected
Groundplane is passive, the sphere active with mass is 1kg and Cube is active with 150kg. everyting else is set to Default.
I keyframed the first 10 frames to make an initial Velocity for the sphere as stated here
How can I add motion to a rigid body?

the sphere hits the cube but the cube does not move.
from around 30 kg for the cube a got some slightly motion after the hit.


Viewport ambient occlusion quality after upgrading to Windows 10

Well after playing around, I have updated all drivers and reinstalled Blender. It looks like if I just turn off ambient occlusion in viewport the problem dissapears.


What numerical CRF values do the assorted output qualities correspond to in the ffmpeg video encoding options

A suggestion from a person on IRC led me to examine the encoded streams which conveniently contain a SEI NAL with the encoding options.  Based on encoding streams with varying output qualities it seems

CRF
32   lowest
29   very low
26   low
23   medium
20   high
17   perceptually lossless

and the lossless option is a different mode with qp=0 which activates the lossless mode of H.264 (which probably uses a PCM mode according to what little I have read).  I did not bother to study the CBR mode.


Blender command line - Change input image when rendering?

You can use a script for this.

You can read command line arguments with the sys module's argv property.
Access the image filepath through the image texture node (lines 9-14).

Code:

import bpy
import sys
from os.path import isfile

# Take image path as the last command line argument
imgPath = sys.argv[-1]

o  = bpy.data.objects['Cube'] # Replace with your actual object's name
t  = o.active_material.node_tree
im = t.nodes['Image Texture'].image

#For the world texture, use something like this:

w  = bpy.data.worlds['World'] # Replace with your actual world's name
w.use_nodes = True
t  = w.node_tree
im = t.nodes['Texture'].image

# If provided image exists set is as the image texture node's image
if isfile( imgPath ): im.filepath = imgPath

Run blender with the script and provided image path thus:

blender.exe pathToBlend\scene.blend -b -P pathToScript\script.py --render-output renderPath --engine CYCLES --render-format PNG --use-extension 1 --render-frame 1 -- pathToImage\image.jpg


Python controle Constrain to Image Bounds

Look in info area

In this case if we open an info window and toggle the setting in the image editor

We see the property is lock_bounds of the uv_editor settings of the image editor space.
Python console code to get there, in same screen. Beware: currently trying to auto complete an image editor  space from another (other than context) screen core dumps my 2.8 build

>>> for i, a in enumerate(C.screen.areas):
...     i, a.type
...
(0, 'PROPERTIES')
(1, 'CONSOLE')
(2, 'OUTLINER')
(3, 'VIEW_3D')
(4, 'IMAGE_EDITOR')
(5, 'INFO')

>>> a  = C.screen.areas[4]
>>> s = a.spaces.active
>>> s
bpy.data.screens['Scripting.001']...SpaceImageEditor

>>> s.uv_editor.lock_bounds = True
>>>

Although can set without, for the menu to show, mesh object needs a UV map and be in edit mode.


Can i know why this happen during animating and how to solve it?

That part of the mesh isn't affected by bone movement coz it might have been missed in the vertex painting. select the bone which caused it and edit the weight paint. add some to weight to the mesh. It should get back together.


How can I see texture on my model besides in shading?

You need to switch render modes. Pick either lookdev, also known as material preview (second from right), or rendered preview (farthest right). See below (highlighted red):


UV Unwrap at seams gives unexpected result

I unwrapped your model again and the other side also gave the same result. Then I tried Smart UV Project and all your shapes came out nicely. In conclusion I think you are better off doing the Smart UV Project instead of the standard Unwrap and as far as why the standard unwrap does this, I think it's because of the way Blender's default unwrap algorithm works.

Hope this helps


How to render with sky texture but get transparent background?

On the render properties under Film check the Transparent box (for Cycles render engine)


Include Other Objects in Sun Lens Flare Compositing Project

In the node editor, you just have to plug the input of Composite node into the Add node output :


I cant use dyntopo because it reacts very slow

The default setting of Dyntopo for the option 'Detailing' is Relative Detail. This means the closer you are to the object the more "high poly" to the mesh becomes when you draw on it with a brush. On the other hand, the further away you are from the object, the more "low poly" it becomes when you draw on it. A setting of 1 or 2px for Relative Detail is way too high in my opinion. You should be fine with 12px, try 6px for more details, 30px for less details.
Alternatively, you can switch the Detailing to Constant Detail. This will make the underlying mesh to have always the same density. Try a value of 150, increase the value if you need more fine details.
In the Overlays (the icon with the 2 circles in the top right corner of the viewport) you can activate the Wireframe overlay that shows the mesh. So you see better what's going on with the density of the mesh.


Blender 2.8: How to output renderings in real time just like what is shown in the viewport?

What you might want to try is to render it using Eevee. You select Eevee as render engine and then you can render your sequence as you would in cycles, just in real-time (or close to it).


What do the parameters of the Cycles Noise Texture do?

I don't think having a math formula will help much in getting the visual effect you want. But if you are really into understanding the math implemented in blender, I think your best chance is looking into the code. The relevant files are /intern/cycles/kernel/shaders/node_noise_texture.osl and /intern/cycles/kernel/shaders/node_texture.h.

I am not familiar with Perlin noise, but looking into the code, "detail" seems to refer to the number of octaves. It is hard for me to understand what "distortion" does, but noise is generated not at original point, but at a point shifted by random (and strange) amount proportional to the distortion.

Since you are more familiar with the stuff I think you'll be able to get more out of it (and maybe post it as an answer).


IK refusing to follow target around Z axis

I deactivated the x-axis limits for the three end bones and the odd error clears up as shown below.

I re-enabled the limits but changed the range from -90 to 90 for all 3 bones and tested it with some fairly exaggerated movements of the curve and the animation seems to behave sensibly.


How do I import a soft body bake into another project?

I solved it.  Turn off disk cache. Turn off Use Library Path.


Blender 2.8 - why can't I see my objects in 3D viewport?

May be it is because of clipping. Set your clip start to something small like 0.0001m
Press 'N' in your keyboard while hovering your mouse in 3D viewport. Then under 'View' adjust clip start.


3D print tools: how can "too thin" warning be only on 1 face?

The thickness measurement uses ray-casting to find faces which are close together.

One thing to consider is the thickness is measured along the direction the face is pointing, so in some cases you could have shapes which give different results with wrinkled vs smooth surfaces).

In general, increase the number of samples for a higher quality result.


You can render (Viewport > Viewport Render Animation) just as particle's   Halo (default particle Point) ... the only one thing that differs is perspective (far particles are smaller than front ones).
Since it isn't geometry, just visual representation, could be memory intensive as representation of vertices.
Under Overlay Properties in 3D view editor enable Statistics to see from how many vertices your "foam" consists. Add Particle system with the same amount of particles as vertices. Frame Start 0 End 1 (or go to Render > Extra > Unborn). Source > Vertices (disable Random Order). Physics Type > None.
Default size 0.1

Size 0.01


Error saying mesh has no vertices when it has vertices

A vertex has no vertex group.
Given the error is complaining that a collection does not have a single member (index 0) and the distances list is made from the vertices
floor.data.vertices[i].groups[0].weight = ( d - minDist ) / ( maxDist - minDist ) #Line 16

implies the error is that a vertex is assigned to no vertex group. Test for this.
if not floor.data.vertices[i].groups:
    continue

or ensure in some other way that all the vertices are assigned at least one group.
See second script in this answer re getting all the vertices in a group.  Example below edited somewhat to match above
import bpy
from collections import defaultdict

scene = bpy.context.scene

vgs = defaultdict(list)
ob = scene.objects.get("GridGrass")
assert(ob is not None) # make sure it exists
me = ob.data
for v in me.vertices:
    for g in v.groups:
        vgs[ob.vertex_groups[g.group].name].append(v)

# print all verts in GrassGrowth vg

print(vgs["GrassGrowth"])


It looks like overlapping UVs. But I am not entirely sure if that is correct. You might want to check your UV wunrapping and see if there are some parts that overlap. If they do: Remove the overlapping side of the UV and bake it again.


If your action contain some keyframes on the "root" bone's channel, all items you assign this action will be mandatorily aligned.

You should remove the root bone's keyframes from the action, and then animate the roots separately. If needed, you can create separate actions, one per character, and mix them with the first action.


UV unwrapping of complex possibly concave polygons

The normal for the plane seems to be the problem. If you recalculate the normal using Ctrl+Shift+N on your mesh, it seems to unwrap correctly.

You can also use Project from View in the UV unwrap options, that seems to work without doing any modification on the mesh.


How to paint a mesh using materials instead of textures

A simple solution is to use masks.
Create an image to use as a mask between your shaders, and paint on that image.

Better if you can see for your self.. here is a simple file ready to
 paint drive.google.com/open?id=0BxfJ7ZIHabcZNXFfdTdiaGd0TGM

If you cannot download the file, this is a very basic idea of the node setup:


Use a Edit Object actuator > Track to instead of Steering actutator.

KX_TrackToActuator Change the time to meet your requeriments of rotation speed time = 0 = instant track to. Between 10 and 30 feels ok.

I made a demo:

Script:

from bge import logic
from random import choice

def change_objective():
    try:
        return choice([obj for obj in logic.getCurrentScene().objects if 'enemy' in obj.getPropertyNames()])
    except Exception as e:
        add_enemies()

def add_enemies():
    for obj in logic.spawn_list:
        logic.getCurrentScene().addObject('enemy',choice(logic.spawn_list))

if not hasattr(logic, 'spawn_list'):
    logic.spawn_list = [obj for obj in logic.getCurrentScene().objects if 'spawn_point' in obj.getPropertyNames()]
    add_enemies()

if logic.getCurrentController().actuators['track'].object is None:
    logic.getCurrentController().actuators['track'].object = change_objective()
    logic.getCurrentController().activate(logic.getCurrentController().actuators['track'])

if logic.getCurrentController().sensors['Ray'].hitObject:
    logic.getCurrentController().sensors['Ray'].hitObject.endObject()
    logic.getCurrentController().actuators['track'].object = None


You have an edge split modifier which is causing the faces to look like they are not smooth shaded, but they are.

The edge split modifier is splitting the surface into individual faces so it is no longer a single surface that can be smoothed.

Increase the edge split angle on the modifier to reduce this effect.


I am using Pillow successfully on MacOSX but maybe not in the cleanest way.

In a nutshell, I'm using Blender's own python34 and I add a path to the proper version of Pillow in my script

Download Pillow for python34 and extract it in a folder – on MacOS, macport & pip automatically take care of that for me
Take the path to Pillow within that folder
In your python script before you import Pillow, add the code below

Python

import sys
path_to_pillow = 'C:/somewhere_on_your_disk/pillow/'
sys.path.append(path_to_pillow)
from PIL import Image

I'll try to run your code and see if it works on my side.

Could you copy the error you're getting when using PIL with Blender ?


Transparent PNGs don't cast shadows (in BI)

Select the "jpg" object and uncheck the "cast" option in the shadow tab.

If you want your object to cast a ray traced shadow you must add a ray tracing light (i.e. a sun lamp) and enable her ray trace option.
In your animation you will also have to move the object toward the camera to separate the plane of the object from the plane of the cast shadow.


Your models exceeded the max polygon limit for 3ds files, which is currently 65536. I've decimated the models for you to go below that number. You can download the zip here:

https://www.dropbox.com/s/mwxzr447792digb/Dragons.zip?dl=0

If you would like a more detailed explanation regarding 3ds exporting please visit this thread:

Export object to a 3ds file error

Have a nice day!


GRLESS stands for "Greater than/Less" and refers to the comparison symbols < and > which mean "smaller than" or "less then", and "greater than".
In most a standard QWERTY keyboards for English speaking countries (like United States, Canada our Great Britain) these symbols are typically in the period . and comma , keys, to the right of the M key.
Elsewhere however, in other international QWERTY layouts it is common to find a dedicated key with both greater than > and less then < keys bundled together, toggled by Shift modifier key.
For Portuguese, Spanish, Greek, Italian, Danish, among  and others layout for example they are located towards the bottom left corner of the keyboard, next to the Z key.


Parenting Object Instancer into Matrix of Flipping Polygon Faces

I found out that I made a mistake up there where I am using the SOURCE Mesh Data to place and rotate the Instance copy where in fact I can easily use the TARGET Mesh Data and Polygon Info node to have the effect I need.

Case Closed.


What you're trying seems hard to do with the Array modifier, you could try with the Mirror modifier, and use an empty as Object:


Apply "backface culling" if the surface is not visible from the given point

At the end I implemented simple check, where I:

1) Calculate the center of triangle, and its normal

2) Calculate direction vector from view point to center of triangle

3) Calculate angle between triangle normal and direction vector

4) If angle is bigger than 90 degrees, the triangle is not visible.


BMesh Approach

I've rejigged your script to use an edit mode bmesh.  Adds a plane on press of "axis key"  X, Y or Z at the cursor location. Rotates the mesh locally about given axis.

It will keep rotating mesh 90 degrees on given axis. (4 times will return to starting point.  Test event type vs previously set axis to remove this behaviour.

bl_info = {
    "name": "test_modal",
    "author": "test",
    "version": (1, 0),
    "blender": (2, 79, 0),
    "description": "test",
    "category": "3D View"}

import bpy
import blf
import bgl
import bmesh
from mathutils import Matrix
from math import radians
axes = "XYZ"
def draw_callback_px(self, context):
    screen_x = context.region.width / 2
    font_id = 0
    blf.size(font_id, 32, 72)
    col = [0, 0, 0, 1]
    if self.axis in axes:
        col[axes.index(self.axis)] = 1
        bgl.glColor4f(*col)
        blf.position(font_id, screen_x, 7, 0)
        blf.draw(font_id, "Axis: %s" % self.axis)

class TestModal(bpy.types.Operator):
    bl_idname = "test.test_modal"
    bl_label = "test"
    bl_options = {'REGISTER', 'GRAB_CURSOR', 'BLOCKING'}
    bm = None
    verts = None
    mwi = None
    def execute(self, context):
        loc = self.mwi * context.scene.cursor_location
        if self.verts is None:
            self.bm = bmesh.from_edit_mesh(context.object.data)
            ret = bmesh.ops.create_grid(self.bm, size=10)
            self.verts = ret["verts"]

            bmesh.ops.translate(
                    self.bm,
                    verts=self.verts,
                    vec=loc)

        bmesh.ops.rotate(
                self.bm,
                verts=self.verts,
                cent=loc,
                matrix=Matrix.Rotation(radians(90.0),
                        3, self.axis))
        bmesh.update_edit_mesh(context.object.data)

    def modal(self, context, event):
        if event.type in axes and event.value == 'PRESS':
            self.axis = event.type
            self.execute(context)

        elif event.type == 'LEFTMOUSE':
            bpy.types.SpaceView3D.draw_handler_remove(self._handle, 'WINDOW')
            self.report({'INFO'}, 'Completed')
            context.area.tag_redraw()
            return {'FINISHED'}

        elif event.type in ('RIGHTMOUSE', 'ESC'):
            bpy.types.SpaceView3D.draw_handler_remove(self._handle, 'WINDOW')
            context.area.tag_redraw()
            if self.bm:
                for v in self.verts:
                    self.bm.verts.remove(v)
                # bmesh.ops.delete(self.bm, geom=self.verts) # ??
                bmesh.update_edit_mesh(context.object.data)
            self.report({'INFO'}, 'Cancelled')

            return {'CANCELLED'}

        return {'RUNNING_MODAL'}

    def invoke(self, context, event):
        args = (self, context)
        self._handle = bpy.types.SpaceView3D.draw_handler_add(draw_callback_px, args, 'WINDOW', 'POST_PIXEL')
        # store vars
        self.axis = "V"
        self.mwi = context.object.matrix_world.inverted()
        context.window_manager.modal_handler_add(self)

        return {'RUNNING_MODAL'}

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

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

if __name__ == "__main__":
    register()


ActiveX controls exist for Powerpoint allowing you to put 3D objects into powerpoint -- see http://www.3dcompress.com/web/download.asp as example.  Using Adobe Illustrator and some back-and-forth, you could handle shapes as SVG thru AI-- Why can't I import a SVG file from Adobe Illustrator or Inkscape? -- which can be edited, and you can export SVG from Blender and import into Powerpoint after converting it to an .emf, which I believe is the only cross-compatible way to do so... But I have only recently started using AI '16.

You can certainly create effects within Blender that can be inserted into PPT as video files, too. A lot of neat visual stuff can be accomplished with embedded AVIs.

You can also create a hyperlink within PPT to a 3D model on a service like Sketchfab if your goal is to show the model itself... but not in an editable way that can be shown containerized within PPT, and this requires an Internet connection to Sketchfab.

Finally, I believe you were able at least in the past to make a Blender game and insert it as a browser object in PPT -- see http://geta3d.com/index.php?option=com_content&view=article&id=15&Itemid=20. I have not done this... and the file is not actually "in" the PPT.... it is linked.

But as I understand your intent, I think the answer is mostly "no"... or "not seamlessly."

EDIT: VRML might offer some compatibility, too, for shapes: VRML 2.0 import/export is an add-on in user preferences.


I seems that your light source is just your world. It wont give you much shadow. Try to set your world in darker and add some lamps. Or you can also change your world to an HDRI.


The Short Answer

I'll post a new answer here because it seems that there is a good deal of confusion, and editing the existing accepted answer isn't the most optimal way to deal with this.

The answer is that Blender is already scene-referred enabled by default. In fact, the entire Blender architecture leans this way, it is just that many learning artists are unaware of the division between a scene referred and display referred working model.

TL; DR If you select Cycles as the default renderer, and save as an EXR, your saved file will already be high dynamic range.

The Longer Answer

So what is High Dynamic Range imaging?

If we explode what we think we know about imaging, we can probably get a good handle on what HDR is, it becomes clear why Cycles renders its data in accordance with scene referred models.

In the physical world, light is a strictly linear phenomenon. If you use a spot meter and measure a point in your frame at 100 units, something in the frame that is twice as illuminated will read 200 units. There is no white. There is no black. Just ratios of light from zero to infinity.

That's right... our values go from 0 all the way up to whatever our highest and brightest value is. This is a scene referred model.

Blender and Cycles and Scene Referred Models

The same holds true in Blender. If you take a default cube and render it in Cycles with 30 point lights in close, the rendered output window might look odd and show the cube as blown out white. But in the internal model, nothing is further from the truth.

If we use the swatch to measure the values on the cube, we can see that the values in the information bar that show up extend well off into the crazy zone. The values to the left of the CM information show the internal model, and the values to the right show the values after the CM transformation. On the left then, are the internal scene referred values, and on the right we see the display referred transformation. So when we flip the various output transforms listed in the color management panel, we are changing the display output transform, and not, in fact, changing the underlying scene referred data at all. Raw, sRGB, or otherwise.

By default, Blender uses a blind and ignorant clip cut that shaves off all of the excess values above the display referred value of 1.0. This means that if you save to an inappropriate file type such as JPEG, PNG, etc., the values on the right side of the CM information bar will be plopped into the file.

If however you save into a data-preserving file format such as EXR, the scene referred data values will be preserved in the file format.

In Closing

So the short answer to how to get HDR values out of Blender is... don't do anything, it already is! No need for Luminance. No need for software magic. Just render via Cycles.

The slightly longer answer involves understanding the differences between a scene referred linear model and a low dynamic range display referred non-linear model, and why the two are vastly different. It also involves understanding why each model is different, and what important things each bring to the table regarding needs.

Phew... a longer explanation than likely wanted, but one that only barely does justice to the complexities of these two models and the science of pixels and light. If anyone reading this finds it at all interesting and want to further their craft, I would strongly suggest you go read the Visual Effects Society Handbook available at CinematicColor.com.


Move both the ends of the helix toward their common centre using proportional editing, then remove doubles and adjust with proportional editing.


Rendering a specific set of frames in one job

It's possible loop over a list of the desired frames, set the correct frame and render it within a Python script.

I didn't manage to automatically enumerate frames according to the Blender Output Panel documentation, so I set the filename manually for each frame and restore the original value afterwards.

The following script should render all even frames as well as all frames that end in a five.

import bpy

scene = bpy.context.scene
tmp_filename = scene.render.filepath

all_frames = range(scene.frame_start, scene.frame_end + 1)

for f in [f for f in all_frames if f%2 == 0 or f%10 == 5]:
    scene.frame_set(f)
    scene.render.filepath = '//frame_{:04d}'.format(f)  # frame_0000 etc.
    bpy.ops.render.render(write_still=True)

scene.render.filepath = tmp_filename

You can select the desired frames by list comprehension like above or use Python's filter function.

The “render with script” approach will make Blender unresponsive during the job, but I think the operating system won't shut the process down unless you tell it to do so, i.e. click on the “Blender is not responding” dialog box.


Is my performance affected by invisible items?

Like is it still running in the background while invisible?
-> if an object is in the renderlayer, whatever the color (even invisibility) blender will still compute it ( so it will decrease performance).
If you don't need this object you can put in in another renderlayer that you don't use.

but control it's invisibility somehow
-> you can use a keyframe on the color of the material to make visible/invisble at the moment you want


Conditional else/if operator to perform different functions

You can check this in the context.

mode = bpy.context.active_object.mode
if mode == 'EDIT':
    ...

elif mode == 'OBJECT':
    ...


How to use select_circle in a modal operator to select faces in edit mode?

Ok I figured it out..
from:
(Is there a way to set the radius of the new circle select tool by python script)
def get_3d_area_and_region(self):
    self.view_3d_area = None
    self.view_3d_region = None
    for area in bpy.context.screen.areas:  # Cycle through all the avaliable areas
        if area.type == "VIEW_3D":  # if area is called VIEW_3D
            for region in area.regions:  # Cycle through all the regions in that area
                if region.type == "WINDOW":  # if the region is WINDOW
                    self.view_3d_area = area  # save the area and region in variables
                    self.view_3d_region = region
                    return
    print ("Could not find area/region")

and then
override = context.copy()
            override['area'] = self.view_3d_area
            override['region'] = self.view_3d_region
            bpy.ops.view3d.select_circle(override, x=event.mouse_region_x, y=event.mouse_region_y, radius=100)

I still don't really understand why the context area information of my own operator is not enough and I still have to query all the areas extra. Oh well, some day I will know more..:)


How to assign a specific color scale to all specific objects in the scene

You only want to iterate thru mesh (or meta i suppose) objects that can have a material.  Here is a sample, changing scene.bool removes material if False, or adds a new material to each object with a differing shade of green.

import bpy
from bpy.props import BoolProperty

def toggle_bool(self, context):

    val = 0.0
    for o in self.objects:
        if o.type not in {'MESH', 'META'}:
            continue

        if self.bool:
            print(o, val)
            mat = bpy.data.materials.new("BSDF")
            mat.diffuse_color = (val, 1, val)

            o.active_material = mat
            val += 0.1
        else:
            o.active_material = None

bpy.types.Scene.bool = BoolProperty(update=toggle_bool)


Besides what is stated in the linked question about the differences between Blender Internal and Cycles what I can add is the following

Historically speaking Cycles is a relatively new addition to Blender. It is a completely external and standalone rendering Engine that interacts with Blender through a built in plugin and python API.
Cycles can even be used with other applications as a standalone rendering solution

Blender Internal on the other hand is integral part of Blender. It is very old, as old as Blender itself, it has been deeply improved throughout the years, but is still deeply integrated and a fundamental part of Blender, without which Blender would not work.

Its material system is also deeply tied to the OpenGL viewport preview system, that is why it's material settings and node setup are very similar to the Game Engine which uses the same OpenGL render engine.

It's also why it has a better more complete material preview system in the viewport. Where Cycles material preview is very basic and limited to image based textures without any kind of shading.

That is bound to change in the future though, Blender 2.78 already has a better preview for procedural textures, and a substantial upgrade is being made for the Blender 2.8 project.

First decoupling and removing dependencies of the Internal Render, modernizing the OpenGL real time preview, and then creating a modern substitute of Blender Internal

I know of no plugins that work with Blender rendering engines, but you can use the built in Compositor for post processing, or any external compositing software that you desire.


Textures are only appearing on Texture Paint tab

Inside the viewport press Ctrl + Tab and select texture paint or press 9 and you will see the same view as in texture paint Work space.


Appling a material to selected faces only

As-salamu alaikum !
You have to create a separate material by clicking on the + button. And then select the faces which you want to have the new material, select the new material and click assign. You're done.


Bump Map Acts differently on two different Meshes

-The texture mapping is done by texture painting with ''alpha'' brushes.

-The scale is applied 1,1,1

Very interesting observation here done by Nathan and some troubling outcomes.

I tried, as shown on the picture, to cut a part of the mesh on which I had the problematic bump mapping, scaled it 1/25... Now the bump works as expected. The more I scale it, the smoother the texture.

So YES it seems to work once I scale but the thing is, the model as real life measurements therefore it's not an option for the application.

So what happens probably is the UV texture is too Hi rez for the mesh (2048x2048) when I thought the problem was the opposite. Blender, by resolving the texture, is squishing the pixels down losing the gradient of the texture.

Is this theory right? I always thought you cannot have too many pixels on your uv map but I never thought there was a pixel scale factor to avoid?

Edit: Finally found the solution in an inelegant way. Found out this is a 'not so well' known bug with bump maps and that's why I was so much trying to find out what I was doing wrong...

Simply using a Divide Node seems to reduce the dynamic range that suffers from being map through ''too small'' polygons.

I can now finally continue to create, sorry blender, hope this will never happen again.


How to I add rotation to my roller coaster track in blender?

Select your curve, go into Edit mode. Select a control point, then press CTRL T to pivot the curve perpendicular to the curve path.


Volumetric light causes lights to flicker in eevee

Seems like Eevee sometimes really has some troubles with volumetric lighting. As they say here: https://developer.blender.org/T71208

I think this was a side effect of a previous bug (in 2.80). basically, the volumes were all shifted 1 voxel further from the camera. This was fixed but now this light leaking is just a side effect of the volume texture being low res.
There is little we can do to fix it. The workaround is to give more precision to the volume (increase samples in volumetric settings) and the shadow maps.

this is a sort of precision error.
This probably won't be fixed anytime soon.
Unless a new groundbreaking volumetric lighting approach is discovered, which is... quite unlikely? You can attempt to alleviate this by making the volumetric lighting texture more fine. This will however use more VRAM so be careful

I hope it will help.
These few quite similar cases may be helpful too:

https://developer.blender.org/T61654
https://blenderartists.org/t/why-spot-light-coming-throught-the-mesh/1227943
EEVEE 2.8 : the light goes through the egdes of a simple cube?


Video editing, encodeing, rendering. Video Always Flickers

You can try to render a mp4 instead of avi. In the Render Tab scroll to Output and choose mpeg-4 or the h.264 Preset and set your desired values, which are similar to ffmpeg settings.


How can I show the vertex positions in viewport?

Well, you are passing no context
(None, None)

but then using some context in draw_callback_px
that is None
you should use POST_PIXEL because it isn't 3d
bpy.types.SpaceView3D.draw_handler_add(draw_callback_px, (bpy.context, None), 'WINDOW', 'POST_PIXEL')

you forgot to import location_3d_to_region_2d libraries
import bpy
from bpy_extras.view3d_utils import location_3d_to_region_2d

Go to Window > Open System Console and you will see all the errors
so you can have something to debug what is happening there

convert coordinates from vertex to world-space
Multiply the world matrix by the object-space vector for world space coordinate:
import bpy

ob = bpy.data.objects['Cube']

v = ob.data.vertices[0].co
mat = ob.matrix_world

# Multiply matrix by vertex
loc = mat @ v

import blf
import bpy
from bpy_extras.view3d_utils import location_3d_to_region_2d

def draw_callback_px(context, dummy):
    ob = bpy.data.objects['Cube']

    v = ob.data.vertices[0].co
    mat = ob.matrix_world

    # Multiply matrix by vertex
    pos = mat @ v

    v3d = context.space_data
    rv3d = v3d.region_3d
    pos_text = location_3d_to_region_2d(context.region, rv3d, pos)

    blf.position(0, pos_text[0], pos_text[1], 0)
    blf.size(0, 1,1)
    blf.draw(0, str(pos))

bpy.types.SpaceView3D.draw_handler_add(draw_callback_px, (bpy.context, None), 'WINDOW', 'POST_PIXEL')

special thanks for @jfranmatheu and @batFINGER


So as I said you have inner faces, but there are hidden so you need to unhide and delete. You can't create edge loops if the edge separates more than 2 faces, and by the way those inner faces are not good for your topology, it may create artifacts.


How can you change the rotation of a mirror modifier?

This is not a direct solution to your problem (that really sounds like an "Apply rotation" problem), but it is a work-around that might allow you to achieve what you want.

Remove the Mirror modifier and instead add an Array modifier.
Add an Empty at the location of the original object.
Set the Empty as Object Offset in the Array modifier.
Rotate the Empty until you get a desired rotation.


There are several things you could try, here are a few:

Try increasing the Drag force in Particle Settings > Physics > Forces to make particles affected by air resistance:

Decrease the influence of the scene Gravity in Particle settings > Field Weights to make particles fall more slowly:

Add a Turbulence force field (ShiftA> Force Field > Turbulence) to make particles drift in random directions, simulating eddies and air currents:

Result:


No distortions with Strokes in a Fisheye render (Cycles)?

Thanks Susu for answering, I found the answer here :
https://developer.blender.org/T70235

"This task can be closed explaining that it's not a supported feature currently.
T68991: Fisheye / panorama in EEVEE is the task to add this in the future."


Alt+M to merge vertices is not working anymore

The new shortcut to merge is M.
No Alt is needed no more.
You can use the right mouse button to bring up the Context Menu, and the shortcuts should be visible there.


How to fix wrong normals after subdivide/poke on a mesh containing a custom split normals layer?

Just a wild guess (we could help more if we had the .blend file to look at): Have you tried removing doubles? Looks like you could have doubles.

Additionally, try going into wireframe to make sure that there isn't an edge connecting the outer 3 vertices underneath the new geometry.


I think your node setup might be reversed, you probably want the glossy shader in the upper slot of the mix shader.

Anyway it may not work that way, if I understand correctly you may need a reflective 'lid' on your box so there's something else for the ground to reflect. Also since 'inside' your box it's dark so there is no light to reflect. Even though it's backfacing is transparent seen from inside it is all mirror so no light is getting in. If you add a light to the inside of your box it might work.

One side note if you are aiming for a 'infinity mirror' effect you may want to bump up the number of reflective bounces for cycles under the Properties Window > Render Tab> Light Paths > Bounces Glossy otherwise after that number of bounces cycles will return black instead of the actual reflection.


Can't select vertices + Loop cut doesn't work

Lazy_traveller, you omitted a crucial bit of information when you asked your question. That crucial bit is the word, "notebook", which you didn't mention until your reply to Hexbob6. There are settings in the user preferences to make use of a laptop possible, but personally, I don't find them very satisfactory. Based upon my own experience, I would most emphatically suggest getting an external full sized keyboard—the kind with a separate numeric keypad—and a 3 button mouse. You should be able to get both for about USD 25.00 (or up, if you're so inclined) in the US. I have both a USB keyboard, and a USB mouse, but I don't know of any reason, if you wanted, that you could not use a bluetooth keyboard or mouse. It works like a charm. If your keyboard and mouse come with separate drivers, I would be sure to make sure they are the latest versons.

As to CTRL-R on your computer not activating loop-cut in Blender, I suspect (don't know for certain, as I don't have a Lenovo Laptop) that the culprit here is that on your laptop, the key combination CTRL-R is being used to control some aspect of the hardware, so the keystroke is being filtered out, and never sent on to Blender.

If you really want to (or must, for whatever reasons) use your notebook with Blender, do a Google search for "using Blender on a laptop", find the most recent tutorial, and adjust the user preferences as indicated in the tutorial. It is even possible to bind loop-cuts to a different key combination than CTRL-R, if necessary.


Based on the file that you uploaded and your question (which I have now edited accordingly), you are actually asking about material settings.

The model does have materials. The problem was that the World color, specifically the Ambient color was set to full white and was overriding everything and making the entire scene look as such.

Here is your render with your current settings.

Here is the same render with the Ambient color set to full white and the others changed to show the contrast.

Here is your render with only the world settings changed (to the default settings) and a hemi lamp instead of the point lamp that you had to make it a bit brighter.


You can try doing this:

Add the curve
Switch to edit mode and  subdivide the curve 4-5 times (press w to subdivide)
Add shrinkwrap modifier to the curve. Accept the default setting and as target set the sphere. Apply the modifier.
Now add the small sphere, with the array modifier and then the curve modifier with the settings you want (as done in the other blend file).

I am attaching the example blend.


Can visibility states of collections be saved on a view layer?

You can use the "Local Collections" in blender 2.81. They can work per ui window and not per view layer.
Go to the "N" Panel>View>Collections, check "Local Collections", and toggle visibility with the eye icon.

You then uncheck "Local Collections" to get back to the previous state.

Alternatively you could duplicate the view layer in the initial state, and then go back to it once you are finished tweaking your scene in the other view layer. The duplicate icon is in the top right corner next to the "remove" icon.


How can I call the active brush within my script?

The value you get with brush = bpy.context.tool_settings.sculpt.brush is a Brush object:

>>> type(bpy.context.tool_settings.sculpt.brush)
<class 'bpy.types.Brush'>

When you access bpy.data.brushes[brush] it expects a name string (i.e. brush.name). Instead you can simply use the brush itself:

def execute(self, context):

    setting = self.setting
    brush = bpy.context.tool_settings.sculpt.brush
    print(brush)

    if setting == 'use_accumulate':
        value = brush.use_accumulate
        print(value)
        brush.use_accumulate = not value
    return {"FINISHED"}

One more suggestion:

Use the supplied context of the operator, this is better than using bpy.context:

brush = context.tool_settings.sculpt.brush


Creating a material similar to the art style of Gareth Davies @spudonkey

Firstly, you can try Edge nodes. http://blendernpr.org/edge-node-v1-2-4-july-2015/
I haven't tried it  myself but I think you can get the result you want.
If that seems too much of a hassle (which it probably is), I've managed to get the colors to be passable as an imitation. Of course you would have to improve this greatly. Here is the setup:

Play around with the noise and the mapping nodes to get diffirent color splashes. Also, it might be necessary for you to play with the Light path node in case the emmision shader's light is shown in other elements in your scene.
Hope this helps a little


Animation Nodes Crashing and not loading properly again

I have seen your question and this is totally a bug that happened while rendering. This is probably not supposed to happen. Try closing blender and restarting your computer. If you are still facing this issue, try recreating the setup. I know it's hard to set it up again, but It is possible. I had to try 7 times just to simulate fire using materials and animating it, but the end result was great. So don't give up and do what I have said. If it doesn't work, try at least 10 times. If it still doesn't work, I think you are using a version of blender that can't support this kind of stuff. (Which is highly unlikely). And a tip for using this sight, don't put stuff or questions regarding the answer as an answer. You can comment on he question instead.
Cheerios,
Aster17


Driver: How to I create a driver for door lock that is opens and closes base on the door handle angle(+/- degrees)?

First you need to remove the Limit Location Constraint from your "Bar" object. This prevents it from moving along the Y axis.
Next select your handle, right click into the X rotation and select Copy As New Driver
Right click into the Y location of the "Bar" object and choose Paste Driver. Right click again and choose Edit Driver. Set the Evaluation to Scripted Expression and change it to (abs(degrees(rot))-45)*0.0002-8.626. (Might need to change it if you want exact values). It should look like this :

No need to tweak the F-curve properties unless you want a special interpolation.
Result :


It looks like you are trying to use Pick image output as is. This answer explains why you are not supposed to use Pick image output. In short, it is intended only for picking the values, and it is not Cryptomatte mask.
Cryptomatte masks are antialiased and have clean edges but you need the software capable of using them. You can export them from Render Layers with File Output node, or connect to Viewer Node and export each Cryptomatte image manually from Image Editor. In simplest case just exporting Crypto*00 mask will be sufficient (it allows up to 2 object or materials per pixel). If you use real Cryptomatte masks and still get imperfect edges it may help to either render with more samples or to enable Accurate Mode for Cryptomatte in View Layer Properties (only available with Cycles CPU rendering). Fortunately, in most cases Accurate Mode is not necessary.
If you want colored and antialiased mask (so using Matte output alone is not sufficient) but do not want to use real Cryptomatte masks directly, there is a simple solution too.
Create this simple emission material:

You can use Object or Material Index instead of Random. Just use Math node to divide by total number of IDs and the result can be connected to the H input. This way for each ID you will get predictable color if you know total number of IDs.
Then assign the Material in View Layer Properties > Override > Material Override (you may also want to override number of samples, it will control AA quality):

The result is perfectly antialiased mask. You can either use Render Result directly (if you want the mask to include all objects), or use Cryptomatte to limit the mask to specific objects you decided to pick:


Use smooth shading: Thoose monkeys have the same amount of vertices, one is shaded "smooth" and one "flat".

About hair sculpting: yuo can use the Snake hook tool in combination with Dynamic topology: thoose horns are maden with a Suzanne SubSurfed level 2, then applied, then a single stroke with Dyntopo 6 pixels.


Yes it possible, but in your case you should do this.

Instead exporting scene, you should open blend4web projects manager

Here you can create a new project

In projects, blend files are assets, they will be used by script files.

In projects manager you will find blend files, exported scenes as json files and JavaScript files to work with:

You can edit Script files using any text editor or from project manager:

here you can find more information about it:
https://www.blend4web.com/en/community/article/341/


How can i change backgrounds between frames in '2D animation' workspace?

A quick and dirty way would be to do this:

Create your second background as another plane anywhere out of camera, then create a keyframe with i > Location for both planes on the last frame before you change shot.
Go forward one frame (so to the first frame of your new shot), move the first background out of the way and put the second background in place, then create another location keyframe for both background planes.
Note that you should be in object mode to do these steps.

But, a much better way would be to use two separate scenes and cut between them using the VSE as explained in this tutorial at around 1h11m. It's worth watching the whole thing if you're just starting with grease pencil.


Chroma key, translate forground, retrieve video from sequence editor

Part 1: The Mask node is (usually) see below rendered at Project dimensions. If your image is not the same size as the Blender project then the mask will not fit. Even if you have drawn it to match in the MCE or UV Image editor.

In this image notice that the mask was drawn to fit around the cube but the rendered version is to small.

Use Scale node with Render Size selected, and choose Fit if the aspect ratio of the image is different to the render dimensions.

Notice that the Mask node can be in Scene Size...

*...or you could make it a predetermined size (to match your source media)

To move the keyed image around, first use the Set Alpha node then the Transform node. You can choose to filter these transformations with Bicubic (better quality).

Also you should use an Alpha Over node to combine a keyed image, instead of a Mix node.

Answering Part 2: You cannot send the output of the VSE to the compositor, sorry. You would have to render it first or copy the values (from the VSE Strip) for frame start and length to a Image/movie node. There is a script that will do this for you. Related Can I add the output of the VSE as input to the node diagram?


Part of my mesh is not affected by bones

I believe from looking that they are separate meshes, in which case you must join them with Ctrl-J and then you should be able to weight paint it, if not you could separate the eyes and parent the separated object to a bone so that it rotates as if it were attached (but this would not morph the mesh like regular bones would).


Both the mirror and array modifiers have settings to automatically merge vertices from the generated parts with the real vertices. When adding or adjusting vertices near the edge you sometimes need to disable these options for a while. Sometimes you also need to adjust the merge limit so that you don't get excessive merges happening.


Why is my render not showing quick fire/smoke

Your Smoke domain material node setup is empty. Nodes are required for a smoke domain using cycles.
See an example here (smoke only):

A more complex setup for fire+smoke:


Workspace custom property doesn't work as driver's variable

Define the prop.

In as much as I agree with @DRF that using workspace properties as input into drivers is not a good idea...

Appears it is with custom properties, ie those defined via custom props panel or via script with

context.workspace["prop"] = 44.55

on the workspace that create the error.  Trying instead the  users property of the workspace it "works" (ie doesn't throw the error) as a driver variable.

If in script a property is defined via

bpy.types.WorkSpace.prop = bpy.props.FloatProperty()

in which case can address it via

context.workspace.prop

it will also work as a driver variable.

Since prop is stored as the custom property of same name will see the API defined message beside it.

Note: as mentioned this "works" as in it doesn't throw an error.  It does however print warnings to the system console, and updating by pressing "Update dependencies" button.

Unhandled ID WSGeneral
add_relation(RNA Target -> Driver) - Could not find op_from (RnaPathKey(id: WSGeneral, prop: 'prop'))
add_relation(RNA Target -> Driver) - Failed, but op_to (OperationKey(type: PARAMETERS, component name: '', operation code: DRIVER, 'location')) was ok


You can use snapping with the increment option. The transformations will snap to the grid. By using the manipulators you can select the axis for the transformation.

The snapping is determined by the size of the grid.

By zooming in or out on orthographic view you can determine the precision of the transformation.

Alternatively you can is change the scale for the grid.

Press N and go to Display. In the scale section you can change the size of the grid and the snapping precision will be changed along with it.

On top of that you can determine the transformations numerically for example: if you want to move sometning 2.5 units on the X axis you'd type G  X
 2 . 5


You need to switch to Cycles Render. If you don't you may not be able to see some stuff you have done.
Switch the viewport shading not to Texture but to Material that way you can see the stuff you have done.
In Edit Mode select what/where you want to color using different kinds of selecting (either use the looping methods (⎈ Ctrl LMBand hold and drag, or hold B LMB hold and drag) or select manually by  RMB clicking and holding ⇧ Shift or ⎈ Ctrl), then create a Material and click assign.

Make sure you name the Materials so you can tell them apart later.


3Ds is mostly considered an aging and hopelessly outdated file format it has intrinsic limitations and is therefore not a good format overall.

There are caps on the number of vertex an object can have, it only supports triangles (no quads or ngons), naming is also limited.

That being said it is still commonly used and relatively well suited for small models and simple objects.

DXF is an exchange file format mostly created for CAD data consisting of lines, arcs, hatches, etc.. It has support for meshes and 3D geometry but is mostly inadequate format for mesh based data since it's focus is on 2D CAD drawing data, paper spaces, layouts, etc.

It may work well if you are importing only 2D drawings like elevations, plans, sections etc, to use as reference for modelling directly in Blender. Otherwise for actual mesh based 3D data it is not the best format.

From the three available, OBJ seems to be the most suited for what you seem to want to achieve. OBJ is also considered an old file format, but has less limitations, and is more versatile than 3Ds and very widely supported in most modelling applications.

Should suit your workflow well enough.


You need to select both of the meshes and select join from the lefthand Tools->Edit->join area.

Once you have done that then you click on the physics tab on the right and select NavMesh Reset Index Values.

if you find you need to join two nav mesh's you probably need to go through and select all your objects, hit CTRL + A and select location, rotation, and scale for all your objects, then rerun the nav mesh generator, it should fix your issues and you won't need to join meshs.


The render result is just the transparent texture?

you need to create a cycles material for visible your render because cycles engine needs nodes tree for render  you can't render blender internal  material into cycles render


The Holdout shader is a non-realistic shader that acts much like a black hole. From a data perspective, it really is exactly that.

The glass shader receives information (in the form of ray casts) about what's behind it, and what can be reflected in it. If that information is coming from a holdout shader, it will be null/black/empty/World/Sky. A glass shader that tries to refract, reflect, or transmit a holdout shader will produce some strange results.

For this reason, a holdout shader is really only useful for compositing.

If you want to have objects in your scene that don't render, there are a number of better ways to do this.

For one, you can disable "renderable" for each object in the outliner by toggling the camera button. This doesn't render the object at all in any regard. I think it still participates in simulations, but it won't be visible, nor cast shadows, nor participate in any other render calculations. This will work with both render engines:

Another option (specific to Cycles) is to turn off visibility for specific types of rays (Properties panel -> Cycles Settings -> Ray Visibility). This can be a really fun thing to play with. For example, if you uncheck only "Camera" then you will see the object's shadow, it will appear in reflections, and it will appear through glass, but it won't be visible if it's directly viewed by the camera.

A third (somewhat more complicated) option is Render Layers. You can put those objects on another layer, and not render that layer. Note: there are some constraints, modifiers, and simulations that don't like having their participants on different layers.


I'm pretty sure that no item has a link to other items that it is used in, you need to loop through arrays and see if the item you are looking for exists.

If you only have a couple of materials in your blend file then you may want to press Home to bring every node into view - it may be located way off to the side. It could also be hiding under another node or inside another group.

If you have a lot of materials you can find which material they are in with a script like this -

import bpy

for mat in bpy.data.materials:
    for mat_node in mat.node_tree.nodes:
        if mat_node.type == 'GROUP' and mat_node.node_tree.name == 'BadGroupName':
            print ("nodegroup in "+mat.name)

If your sure you don't want the group you could remove it instead of showing the material name, I'd rather look to make sure deleting it doesn't break things unexpectedly. You could also select the group node and bring it into view.


To straighten vertices to a line:

Set pivot to 'Active Element'

Select the 2 vertices at the ends, and create a Custom Transform Orientation from them. (The little '+' in the header's Transform Orientation dropdown)

With all 3 vertices selected, and one of the ends selected last, so active, and the new transform orientation active, hit S Shift Y 0, scaling to 0 in all dimensions, except 'Y', the one along the line between the end vertices.


Should the obj file always contain the keyword "mtllib" for textured models?


How to smoothen out a pit in a curved surface

One way is to use the Cast modifier.

Select the area you want to 'smoothen' and add it to a vertex group (I named it ball part)
Add a Cast modifier set to Sphere and limited to the vertex group.
Use the Factor, Radius and Size sliders to correct the shape.


Is overlapping but not connected geometry bad?

Should you avoid it? Yes.
Does it necessarily look bad?
It depends on the direction of the normals of the two overlapping faces.
If the normals are facing the same way you might have some bizarre results in Unity or other game engines. If they're facing different ways and you're using a 1 sided material shader it's not going to look wrong, just 2 sided, and you might not even notice it because a side would be on the inside, and if one only cares about triangle/face count it's totally ignorable.
Anyway, yes, as I said, do avoid overlapping things if you can.


Remove Doubles is now renamed as Merge By Distance.
and it is located under

  Mesh> Clean Up > Merge By Distance

and

  Vertex > Merge Vertices > By Distance

(in Edit mode )

Shortcut key is Alt+M > By Distance


How to save cut video as a video file in Blender 2.92.0

I found it! Turns out, it is the menu Render → Render Animation: it makes a window pop up, and after that window finishes playing, a video file appears.
But as I mentioned, I tried that menu and it didn't work, right? So why wasn't I finding it? Well, turns out when you set up the output directory for a file, you must end it with a slash. Otherwise the last /-separated chunk of the text would be interpreted as part of a resulting filename. Which means that if I wrote a path /tmp/foo (expecting the file to end up in the /tmp/foo directory that I created), then it saves to a file like /tmp/foo-SOME-POSTFIX.mkv, and I had too much stuff in my /tmp directory, so I simply missed it.


Vertex Indices change after using Subsurf Modifier

Vertex indices are not meant to be used to reference the actual vertex. They are an internal position in a list, not some property of the verte itself. For instance if you apply the bevel modifier, how would you expect the indices to go? All of them have moved.

If you want to access the location of the original vertices, you could store a copy of the mesh. (not necessarily assigned to an object either) If you want to find the new vertices that map to the old ones, the only way I can think of is to iterate through the new objects vertices, find the closest old-mesh vertices, and threshold so only if they are very close does it count them as the same.


How to to set fixed delta time for physics update?

Blender as far as i know Blender not use delta time for physics, every frame the physics is  re-calculated.

To set the quantity of framerate per second go to Properties tab > render tab > Display > Animation frame rate.

To set the physics steps go to `Properties tab > scene tab >Physics > Physics steps``.


Why am I getting magnetic effects from cloth objects?

What appeared to be the issue is the "Single Sided" option in Collision settings. Somewhere along the way I unchecked that, which made the cloth try and wrap around the ring. It's confusing since it looks magnetic, which can be set elsewhere.


Moving Back and Forth - Animation Node(PYTHON) vs Unity (C-SHARP) Boolean Switch Logic

I see no good reason to discretize such simple animation. A parametric approach might be better. To move an object between 0 and 1 in 20 frames, you can use such node tree:

To see why it works, plot the function. Another approach would be to use the animation nodes in Animation Nodes:


I think I found the solution by myself. There are missing argumets in the python-script netrender/master.py.

This thread was helpful:
https://developer.blender.org/rBA8b56ce969db281579bf35000ef7b20a8d9590dbb

I reported a bug here:
https://developer.blender.org/T50475


Aligning tangents in connecting NURBS-curves

you can snap disjoint curves together, and thereby manually make a perfect tangent, then translate that segment away and snap it to the end of one of the Curves. It's easy but isn't exactly obvious..


Blender 2.78c on CentOS python environment

If you can, install from system repositories. I've heard that CentOS's isn't very good at this, and on Windows you can't, so here are some other solutions.

The first thing to try is deleting the python folder from the blender install. (you don't need to symlink it, remove it entirely) This should make it use the system python.

The next thing to try is to install pip inside blender. This isn't too hard to do, and is useful in many other cases (eg want a portable version of blender with a specific module)

Download get-pip.py and rename it to get_pip.py
Start blender's python runtime (inside blender/2.78/python/bin/) and run the executable (python3.5m on linux 2.78c) from a terminal.
Add your download folder to the path so python can find get_pip. Do this with:

import sys
sys.path.append('~/Downloads')  # Change path as required

Now you should be able to import get_pip, and run get_pip.main().
Then, to install things, you can use:

import pip
pip.main(['install', 'osgeo'])

You could try it from blender's built in console, but on the windows version this does funny things (like opening lots of instances of blender!),  so I haven't gone into detail.


A variation of that should be possible, certainly.

DXF import was a bit sketchy last time I tried. You may need to export in DXF R14 format or something relatively old like that. FBX is more reliable.

You can certainly snap to vertices of the imported file. You'll probably add a dummy mesh (e.g. a plane), enter edit mode, then repeatedly press 'e' to extrude vertices along the background (imported) mesh/lines.

Alternatively you can just select vertices from the import mesh and extrude them. Might want to separate them from the original mesh to suit your workflow. Just press 'p' when you've selected a bunch of vertices that you want to turn into a new object.

Personally I prefer place walls as a single line along the wall centrelines and extrude vertically. Then you can adjust wall thickness easily using a Solidify modifier and you have fewer vertices to contend with, which makes cutting holes for doors and windows easier.


There is nothing wrong with your file. Blender's viewer is broken, and has been broken for many years.

It cannot display pixels that are luminous and transparent (it cannot do proper Associated alpha). Switch to Color (RGB) view instead of color and Alpha. You should be able to see the halos and blurs.

As an alternative composite over a black background.

Beware that if you try to save the image as png with alpha you will get no halos or blurs, as the format doesn't support associated alpha either.

More details on these links:

Glow effect invisible on transparent background

How do I get the Glare node to output transparent instead of Black background

Render semi-transparent volume with cycles


help with walls when extruding - total beginner

Generally two Steps to get rid of them:

For all "zero-area" faces, A to select all, then W  > Remove Doubles;
For the "zero-thickness" frame on the window (where non-manifold appears), you can select them manually, then X to delete. Or, if there are too many of them and you want a quicker selection, ShiftCtrlAltM to select all non-manifold elements (must be operated in Vertex/Edge Select mode), then on the menu: Select > Select Loop Inner-Region. Then delete the selected faces.

EDIT:

In 2.72 or later version, for the second step above, another convenient way is:
First, be sure that you using Edge Select mode, then ShiftCtrlAltM, then hit F6, toggle nothing except Boundaries, then switch to Face Select mode while holding Ctrl. Then delete all faces that are selected.


As long as the denoiser in inserted in compositor between render layer and composite node, and "compositing" is checked in post processing tab (as default), every frame of the animation will be automatically processed.