How do I get a cylinder arrangement of arrays with gradient (increasing/decreasing) heights?

You have several flaws in your design.

The normal distribution is usually a two-dimensional function which only takes one variable as an input. You could multiply f(x) and f(y) and use the resulting value as the height.
Nearing a lot of iterations, you shouldn't use bpy.ops
Use the bmesh module to edit meshes and link the data blocks manually to the scene.
Vector objects can be instantiated with a tuple
Blender is slow with a lot of objects, aim to include all geometry in one object in the future

The resulting code may seem convoluted, but is faster and easier to maintain.

import bpy
import bmesh
import math
from mathutils import Vector

RADIUS = 0.16
HEIGHT = 32
SEGMENTS = 32
DISTANCE = 1
COLS = 20
ROWS = 20
SCALE = 1

MEAN = 0
STD_DEVIATION = 4

def normal_dist(x):
    global MEAN, STD_DEVIATION
    mean = MEAN
    std_deviation = STD_DEVIATION

    exponent = - math.pow(x - mean, 2) / (2 * math.pow(std_deviation, 2))
    return 1 / (std_deviation * math.pow(2*math.pi, 0.5)) * math.exp(exponent)

bm = bmesh.new()
bmesh.ops.create_circle(bm, segments=SEGMENTS, diameter=RADIUS*2, cap_ends=True)
bm.faces.ensure_lookup_table()
ret = bmesh.ops.extrude_discrete_faces(bm, faces=bm.faces)
bmesh.ops.translate(bm, vec=Vector((0,0, HEIGHT)), verts=ret['faces'][0].verts)

scn = bpy.context.scene

name = "me"

for i in range(COLS):
    for j in range(ROWS):
        pos = Vector((i - COLS/2, j - COLS/2, 0))
        pos *= DISTANCE

        name = "cylinder_" + str(i) + "_" + str(j)
        if name not in bpy.data.meshes:
            me = bpy.data.meshes.new(name)
        else:
            me = bpy.data.meshes[name]
        bm.to_mesh(me)

        if name not in bpy.data.objects:
            ob = bpy.data.objects.new(name, me)
        else:
            ob = bpy.data.objects[name]
            ob.data = me

        ob.location = pos.copy()
        pos *= SCALE
        ob.scale.z = normal_dist(pos.x) * normal_dist(pos.y) * HEIGHT

        if ob.name not in scn.objects:
            scn.objects.link(ob)

bm.free()

Sooo cool.


Objects are not affected by lights in cycles

I've made it a little bit different then @lemon.

Light changed to Sun > Emission 70.
Normal connected to Glossy material.


Type with curvy front face / round front bevel

By tweaking both the Bevel Depth and Modification Offset you should be able to achieve quite good results:

Start by increasing the depth: the font will increse its outline while creating the curved. Then use a negative offset value to compensate this growth and to make the flat face as small as possible. the You should also ensure that the beveling resolution is high enough in order to achieve the wanted smooth surface.

Then you could convert the text object to a mesh. This way you'll have more control upon the shading of the sharp edges. I marked them manually in the following example:


Exporting rotations of selected objects to a text file

You already outlined everything that needs to be done. Rotation can be reached at .rotation_euler:

Note that you can find this information by typing stuff to the console and hitting ctrl+space for auto complete.

The values are in radians so you need an easy way to convert them. You can just multiply the values by 57.29577951308232, or you could do from math import degrees or from math import degrees, radians so you have functions that can convert between the two for you.

Everything from math is imported in the console so you could just get the degrees of x rotation of the active object by typing degrees(bpy.context.object.rotation_euler.x) in the console to check that this indeed does work.

In a script this would look something like:

import bpy
from math import degrees

result = ''

for o in bpy.context.selected_objects:
    #something else that you need to get to result
    n = o.name
    r = o.rotation_euler
    result += "%s - X:%.3f, Y:%.3f, Z:%.3f \n" % (n, degrees(r.x), degrees(r.y), degrees(r.z))
    # carry on to do whatever else
#write to file


They are different engines - for different purposes.

LuxCoreRender is an extremely advanced, physically accurate engine. It supports both path tracing (rays are shot from the camera) and bidirectional path tracing (rays are shot from both the camera and light sources). LuxCoreRender also has multiple sampling types, along with many other state-of-the-art features that are hard to find even in professional paid render engines. There are also many quality-of-life features that LuxCoreRender has, that make it fast for certain tasks.
 LuxCore does have disadvantages, however. The biggest is it's absolutely terrible motion blur. Because it's motion blur is so bad, it should not be used for animation, like at all.

Cycles is very good as well. It's more typical, and well rounded. You know cycles, it's good! It struggles with things like caustics and dispersion, though.

Here's the final verdict from me. Cycles works pretty great most of the time. And, I recommend using it most of the time. It's shader system is excellent, and allows for incredible effects. LuxCoreRender is amazing too, but is only worth using for archviz and scenes with lots of glass and complex stuff like that. LuxCoreRender was actually developed primarily for archviz, by the way.

I hope this helps!

EDIT: about biases; cycles is partially biased, and LuxCore can be completely unbiased, but can also be biased depending on what you want for that specific scene. In LuxCore, you can control it


Is it possible to opitimize Cycles' refraction material?

This might be a little bit of a late answer, but Cycles' caustics handles large light sources very well, but small ones with difficulty. I'd recommend using the Light Path node, and two lamps for every light source. One is a lamp that shines for everything that is NOT reflective/refractive. The other one is a large lamp for ONLY reflective/refractive caustics.

To do this, I'd use the Is Reflection Ray and the Is Transmission Ray outputs of the Light Path node.


Can not access game object added in overlay scene

You can not use a variable for KX_GameObject that contains characters like ".", ",", "!" etc. You must use only lowercase and uppercase letters and numbers. In this case you must do something like:

HUDtext = hud.ojects["HUD.text"]

or

HUD_text = hud.objects["HUD.text"]

You can use any variable name that contains only letters and numbers. Note that it can't start with number.


How do I rotate an object with a custom button and panel using python scripting?

One way might be a modal operator which tracks mouse movements and applies it to pose bone rotation. The operator modal template (Goto Scripting View -> Templates -> Python -> Operator modal) should be a good starting point.

Here is a small example:

import bpy
from bpy.props import IntProperty, FloatProperty

class ModalOperator(bpy.types.Operator):
    """Rotate a bone with the mouse, example"""
    bl_idname = "object.modal_operator"
    bl_label = "Simple Modal Operator"

    first_mouse_x = IntProperty()
    first_value = FloatProperty()

    def modal(self, context, event):
        if event.type == 'MOUSEMOVE':
            delta = self.first_mouse_x - event.mouse_x
            self.pbone.rotation_euler.x = self.first_value + delta * 0.1

        elif event.type == 'LEFTMOUSE':
            return {'FINISHED'}

        return {'RUNNING_MODAL'}

    def invoke(self, context, event):
        self.first_mouse_x = event.mouse_x
        self.pbone = context.selected_pose_bones[0] # <- put your bone here instead
        self.first_value = self.pbone.rotation_euler.x

        context.window_manager.modal_handler_add(self)
        return {'RUNNING_MODAL'}

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

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

if __name__ == "__main__":
    register()

    # test call
    bpy.ops.object.modal_operator('INVOKE_DEFAULT')

You can then add your operator to your panel


How do you disable physics force field for multiple objects/meshes?

The object with the force field has circles around it, so it should be shown, else you could play the simulation with AltA and see where the force comes from :)


This is generally a result of the complexity of working with the subdivision surface modifier. The closer together your edge loops are, the more of a "crease" you will get.
To solve this, I would recommend individually selecting the edge loops on each side of the center edge loop where the crease is and edge sliding (double tap G) them away from each other until the "crease" is smoothed out. As an aside, you should consider if those three edge loops are even needed: is it possible to get away with only one?
Please edit your post to share your blend file too - it would really help!
You can use this site to share blend files: https://blend-exchange.giantcowfilms.com/


Object renders fine in cycles but disappears in eevee render

This was happened to me a while ago and don't know the exact solution but this works for me:

Go to [Output settings-> Post Processing] and uncheck compositing
Go to [output settings-> Output] and change the color from 'RGBA' to 'RGB'

let me know If this works or not.


How to create alpha / height maps in Blender for use in e. g. Substance Painter?

I finally found a good, working and as it turns out easy solution to this problem. Credits go to Petr Utinek, he made a tutorial video here.

The steps (I modified them a bit):

Create a mesh, e. g. a gear and switch to Top Ortho view

Select the camera, hit space, search "Align Camera to View" and apply it
Select Render tab, change resolution to 2048x2048 and 100%

Select Data, Orthographic and adjust the Orhtographic Scale

Select the Mesh and assign a Material to it
Select Node Editor, Compositing and Use Nodes
Add a Normalize Node and an Invert Node and link the nodes like this:

add a Plane below the Mesh

Render the scene and save the image

Or to follow the initial question: Easy to re-use by simply e. g. deleting the gear and replacing it with a cylinder

which will result in this


Blender does not automatically create manifold when a space is enclosed by faces

Manifold geometry just means it’s watertight. Your printer should automatically translate from a sort of paper model to something solid. It does this by working with the face normals. If the add-on thinks the geometry is not manifold, there might be a hole in it somewhere, or maybe some of the face normals are oriented backwards. Try selecting everything, then using “Merge by distance” to merge verses that are in the same mathematical position but are not connected. After that, with success or failure, try re-calculating all the normals to the outside.


In order to repeat the texture, at the same time mirroring it, you should check 2 options in the Image Mapping scroll:

increase value of the Repeat slider to something more, than 1 (otherwise Mirror options will continue being disabled, like you've mentioned);
check Mirror X and / or Mirror Y checkboxes.

The texture will be repeating as the pattern, mirrored on selected axes.


Displace modifier does not match the texture

Ok everything you saw in my first post was properly set, except that my unwrapping was wrong : some parts of the mesh (a complex one btw) were crossing each other on the UV map, causing the wrong displacement mapping.

That was pretty obvious in the end.

I deliberately chose to cross some parts of it because I wanted a specific texture mapping. So, for any person interested in this post, I guess that it would be possible to correctly map the displacement with some crossing unwrapped parts of the mesh by using multiple UV map.


save intermediate render result to OpenEXR not working (Cycles/ v.2.79)

If Blender is crashing during super high-resolution render for whatever reason, consider using add-ons for precise region render, like blender-renderborder or accurate-render-border (not sure about their 2.8 compatibility) or with some python usage. Enabling Crop in render settings can also help.

Then stich small chunks into one image in PS, Gimp or other image editor.


How to make one object pass through the holes of another?

Most likely you have your collision set to the default of 'Convex Hull' in the Rigid Body settings. Try changing to 'Mesh'.


Press and hold Ctrl and Shift while rotating the Mouse Wheel to rotate your view:

Or Press Numpad 1  to go back to Front view or  Numpad 3 for Left view...


How to get Cloth to ignore collisions with specific vertex groups?

Instead of trying to selectively ignore vertices, just add some collision objects that follow the legs. Create some super simple ellipsoid colliders that are parented to his thighs, knees, and/or calves and make them more-or-less the same size as the legs.

Bob's your uncle.


Basically, you want to increase the Wavelength and Amplitude of the Sinus when the camera go closer to the object. You can do that with Drivers.

On the picture below, you can see the settings for the Wavelength driver :

a variable (named dist) return the distance between Cube and Camera
we invert it (1/dist), cause we want the value to decrease when the distance increase
we multiply it by a value (*200), which define the overall amplitude.

To find the right value, you can do trial and error, or calculate it. Here you can see dist is 10.439 ; say your desired Wavelength is 20 ; 1/10.439*x = 20 -> x = 20*10.439 = more or less 200.

The method is exactly the same for Amplitude. I used (1/dist)*30.


In blender 2.8 how do you make a local instance of an object in use by multiple scenes?

Make New Scene with Copy Settings. Go to your first scene and link all necessary object to newly created scene. Go to your new scene and now Make Single User under Object->Relations works as expected.


Texture messes up after extruding a modified plane

The error results from anti-aliasing / inaccuracy / interpolation of the UV across faces. A solution is to get each face to read from a single point in the image.
This involves a couple more steps than it should, IMO.. it should not be necessary to split the geometry to do this, seams should do the job... but still, in 2.91, they don't.
You've probably already done most of this.. starting in the flat, with a simple plane:

Subdivide your plane with 15 cuts for 16x16 pixels, as you have.
Edit mode, Edge, All selected, right-click menu > Edge Split
UV Edit.. U Unwrap > Project from View (Bounds)
With the pivot in the UV Edit window set to 2D cursor, select all, move faces so the bottom left of the map is at the bottom left of the texture, select the vertex there, and Shift S snap the cursor to it.
Scale the map in X and Y so each face covers a pixel..

And as above, switch pivot to 'Individual Origins', and scale the UV faces to 0.
Back in the 3D View, AltM Merge > By Distance, weld the faces in the geometry back together.

Now the result of an extrusion or Solidify modifier will be clean.


Render problem. Mesh is cut on final render or in render display

Sorry, im not very smart. I didnt know, that 'render' ratio, that gave opportunity to see object in render is switced off


How to access Fracture Cells / Fracture Modifier in Blender 2.80?

I got a few answers across multiple channels:

#blender on irc.freenode.net:

   d33tah, try #blenderfracture (might need to wait for a response)

A thread on blenderartists.org:

  It has been removed for now, 2.8+ will get mantaflow which is much better for that stuff. It was supposed to be in the 2.8 release but they fell behind, So now they are shooting for 2.81.

An answer on blender.chat:

  Fracture modifier has never been part of Blender releases. It’s a separated branch that will be merged at some point in the 2.8x releases. But you can download a fracture modifier build from graphicall.org.


Is there a way to rig another character to have the same weight paint?

https://www.reddit.com/r/blenderhelp/comments/3uot2q/copy_bone_weights_to_another_object/
That looks like your issue. I googled "copy weight paint blender" .
specifically
Go to 'Weights'>'Transfer Weights' from the menu to the left of [Weight Paint]


Skinning A Simple Tank Track For Unity3D

weight is 100% if more than 0 and no other weight. To limit the effect, you have to use another bone (static or another wheel) with the resulting weight on it to counter the no-other-weight effect.


how to check what shape key connected to bone?

As far as I know, you can only move the bone and read in the properties panel, shape keys tab, which is (or are) driven.


Can Blender use the open-source Nouveau Nvidia driver for rendering?

CUDA only works with the Proprietary NVidia Driver. If you want to render using GPU you need to install it.

Nouveau doesn't support CUDA. Blender will run, and render, without CUDA, but it will not use the GPU.

Read: Can CUDA operate with open source Nvidia driver or only with Nvidia proprietary driver?

and the Nouveau article on wikipedia


If you want realistic results in cycles, there is no way around using spotlights and volume scatter with optimized render settings.

Here is a link to a similar question:
Volumetric Spot Light with Cycles

If you want to fake it, there is your way of doing it, however I would suggest to control the transparency of the "cone" with a gradient or ramp map.
Alternatively there is the camera node with the distance connector that can be used to control the transparency of the cone transparency (closer up the cone should be more transparent).

Unfortunately this will still give relatively amateurish results as the cone will always stay sharp at the edges, which spotlights dont do.

Another way would be to create an alpha texture with a faded gradient and use planes to fake the cone, unfortunately this will only work good if the result is not animated and doesnt change perspective.


Is it possible to convert hair to alpha planes?

Particle edit & Render as Object

Blender has some nice tools to work with hairs.

To assign planes to hairs, use the Object (or Group) option you can find in the Render panel of the particle system.

Texture the plane and all the particles will follow that.

You can comb hair particles in the particle Edit Mode.

Once satisfied, you can run the "Make duplicates real" operator to convert the particles to individual meshes so you'll be able to export the objects fbx, obj... and use them in other softwares.


What auto rigging system should I use to rig my character?

Have you looked into Auto-Rig Pro(ARP)? It's a purchasable add-on. From the reviews and videos that I have seen, it looks pretty solid.


Welcome to Blender Stack Exchange!

You'll want to use something known as Parenting to do this. Joining only works if the objects are the same type, and only on certain types of objects, for example meshes.

To use parenting, select the object that you want to be the follower, and then the object that you want it to follow. Press Ctrl+P and choose "Object". Now the follower (child) will be joined to the parent object and follow wherever it moves. You can still move the child object independently as well.


Shading lines on corners of extruded faces on cylinder

It looks like you've created bevels around your hole, so it makes ngons on this part of your cylinder. You will have almost no pinching with this solution:


SV Sverchok : Points in mesh, go outside mesh

point_inside_mesh is agnostic to the input, as long as it is a manifold mesh.

for example: a torus/donut with distortion.

The only feature that the points_inside_mesh node won't handle automatically is multiplanar-ngons, if one of your meshes has a face where not all edges lie in the same plane, then you must pre-process that face to get useful results.

This for instance would not be a good input, the results of both "Regular" and "Multisample" modes are going to be undefined. The NGon will not be tessellated according to everyone's tastes.

This however, is fine. The ngon gets triangulated by the triangulate Mesh node. I'm not sure if it makes a difference to the triangulation bmesh.ops whether you triangulate the ngon while they're still flat, or if you insert that triangulate node after the Noise Displace.

the downside with the automated tessellation is that it behaves best with planar ngons, passing it non-planar / multi-planar ngons requires a more sophisticated algorithm to generate nice quad/tri topology.


how to continuously rotate an image in the video editor

You add a transform effect strip then keyframe the start and end with rotation changes. Otherwise you can add a couple small rotation keyframes to check speed then add a Cycle modifier to the f-curve of the .blend that extends the animation out past the keyframes.
f-curve modifiers 2.6 wiki

  Cycles mode - Repeat with Offset
  : Repeats the curve data, but offsets the value of the first point to the value of the last point each cycle.


How do I change camera targets when following a path?

You don't "change" camera targets, but you can have several Track-To constraints in the same object with different influence values at any given time.

Just keyframe the Influence parameter over the course of the animation so it points where you want at the correct moment.


Wrong faces being seperated from one another after unwrap

Under UV mapping/Smart UV project/ Change the angle limit to something like 40 and run it again. Or a value like 80


Why aren't these objects rotating? Physics question


How do I make a curve that goes through a series of points?

You can "draw" connected points by pressing Ctrl and the right mouse button. The bézier hadles will be calculated automatically.

Or you can use the grease pencil to draw and convert the strokes to curves.
Curve editing in blender is still quite rudimentary, for complex shapes it is a lot easier to use a vector drawing program (like inkscape, illustrator, etc), save the path as SVG and import into blender.


It could be caused by the "Add Leaf Bones" option. It is checked by default. You can find it in the export options under "Armatures".


Difference between stacking and extruding meshes?

I would recommend using one mesh. You can easily get the mesh you want in this instance by selecting the desired face, pressing E to extrude and then S to scale. Now press E to extrude again, and you have the desired mesh, created in three simple commands.

This method works in many other instances, even on N-Gon or Tri faces. This is a good general modelling technique to know for any modelling project.


Yes, you can modify your model in blender, after importing it from an external file supported by an import plugin (fbx is shipped and enabled by default) See the File > Import menu. Other formats could be enabled through the user preference menu, or even added to the standard blender distribution through separate plugins.

After importing, you should have a regular model as if you modeled it into blender from scratch. An then you can save it as .blend or export it to other formats.

Just keep in mind that import/export plugins may have sometime limitations, due to their update status, sometimes unsolvable differences between different modeling programs, or their own good implemetation, but in general they get better and better, in blender, in particular most widely used ones (as fbx).


How do I bring the cursor and X/Y intersection to the centre of the screen?

With shift + MiddleMouseButton you can drag the the x- and y-axis + the cursor to the center of your screen. Afterwards your circle and image will still be to the bottom left. Now you can re-center the image as you did before. To center the donout, rightclick on it, click on the + sign in the top right and set the location to x: 0, y:0, z:0


How to create material that goes along curved mesh?

If you dont mind you can use just a Curve.
Shape

add Curve Circle, in edit mode Rotate 45, Duplicate and move 2.8 on X axis
select all vertices switch handles to Free V and delete from both circles the center segment
select end points and press F to connect

To get even distribution of colors you need to evenly distribut a curve's control points, that is not right now, but you can add another curve object - straight like, subdivide several times and deform this curve by previously shaped curve.

Add some stickness to curve (tube) - go to Properties editor > Object Data > Geometry >  Bevel > Depth
It is better to keep curve in type Shape > 2D and Fill > None
Add Curve modifier (ensure origins both objects are at the same place)
Moving along X axis will move along shape

2.7x Material

Plug UV Texture Coordinate socket into Separate XYZ node
and use X socket to lug into ColorRamp
Enable under Properties editor > Object Data > Texture Space > Use UV for mapping.

To see material switch to Rendered type view mode.

2.9x Material
is like here, you don't have to worry about UV in curve properties, it is set by default.

Notes:
Changing X Location will move gradient along curve.

Changing X Scale in Mapping node will change gradient scale.


Making a textured sphere using color coded height map?

Run the color through a "Seperate HSV" node to get the Hue. Then invert the hue and you'll have a more or less accurate result. If you want to make the mountains taller relative to the grasslands I imagine you could do it using RGB curves node. You may also want to get rid of the sea's variation in depth, so that it doesn't look like the sea is uneven. I would recommend doing that by hand or at least without blender.
Let me add, that you don't really want real displacement. You would need extremely dense geometry and it wouldn't look good either. A planet is so large, that its surface imperfections and bumps can not be noticed from space. At least our planet is like that. A simple bump node would give you the detail you need in the reflections (mainly via fresnel). Hope this helps.


Is it possible to use four corners of a single marker for a plane track?

Using Python, we can just create a new track for each of the corners, which in turn allows to create a classical Plane Track.

  tracking = D.movieclips['clip.avi'].tracking
  begin, end = C.scene.frame_start, C.scene.frame_end
  corners = [tracking.tracks.new(frame=begin) for i in range(4)]
  track = tracking.tracks['Track']
  for frame in range(begin, end+1):
     track_marker = track.markers.find_frame(frame)
     for i, corner in enumerate(corners):
        corner.markers.insert_frame(frame)
        corner_marker = corner.markers.find_frame(frame)
        corner_marker.co = track_marker.pattern_corners[i]
        corner_marker.co += track_marker.co

However, this is quite clumsy a solution.


To give the impression of a partially cloudy sky you could place a plane above your scene and use a Mix node to vary between Diffuse and Transparent shader using a Texture such as Musgrave or Noise as shown :

With the plane high above your scene it won’t be visible to the camera but will still affect the parallel rays of the sun lamp. Alternatively, if it would be visible to the camera due to the camera angle you could use a Light Path ‘Is Camera Ray’ node to make it fully transparent to the camera while still casting shadows.


Exporting entire world from blender to unreal without exporting same asset multiple times

I don't have much experience with this, so I am going to give you an answer that is a basic starting point.  If you haven't already you should download an add on from Epic Games called "Pipeline: Send to Unreal".  In this add on there are some options about "exporting collections" and "combining child meshes", as well as various FBX related controls.   Further research into these settings should help to answer your question more.
https://epicgames.github.io/BlenderTools/send2ue/quickstart.html


That's probably because you are in Blender Internal,
try switching to Cycles.


How to move vertices upwards while bone rotates

I suppose it wouldn't have hurt to just search around the tools a bit more. I discovered that the Transform tool works best for this. I created two bones for those areas near the legs and then mapped a certain rotation range of the thighs to the increase in Z I wanted the bones to have. Just remember that you want to set the Owner to "Local with Parent" if you ever plan on moving your object around, and do something similar with Target (for me I set that to Local Space).


Tables Z scale is negative, so change it from -0.192 to 0.192 and then rotate Y 180 degrees. Also cylinder scales are all negatives (X, Y and Z are all -0.304) change them all to 0.304. After you get rid of those negative scales try again if it works now as it should.


Why does my render layer node not have the expected number of outputs?

Enabling this will give you all the extra input (e.g. Noisy Image, Denoising Normal...)


Go to Render Settings and switch the render engine to Workbench. This is the render engine the viewport uses and is responsible for matcap lighting.

Then select the Matcap you want to use just like you would do from the viewport by using the Lighting dropdown below the Sampling menu. Once you press render, each frame will be created using the lighting type that you have specified. It also renders lighting fast because Workbench is designed to provide instantaneous shading for the viewport.

No fancy node editor work required, just switch the render engine, choose a matcap, and that's about it.


Help with implementing Shape Key Drivers

You need to know, that weight are not describe how bone influence on mesh. Instead, weight describes how the effect on the mesh is distributed between the bones. So if you have setup only one bone, 100% affects is from this bone even if you set 0.0001 weight.

Also, you can get nicer and smother results if you set armature modifier before subsurf.


In the folder how do I make blender files show a preview of themodel?

Usually, it's done via the windows installer file but sometimes it doesn't work.

You can do it manually though, using command lines.

First, you have to navigate to your Blender installation folder, which by default is C:/Program files/Blender Foundation/Blender.
A simple way to do it is to right-click a Blender shortcut and hit "open file location". You can find one of these shortcuts on your desktop, or in your start menu by typing in "Blender" in the search bar.
Or, if Blender is already running, right-click its icon in the taskbar → Properties → file location.

Once in Blender's folder, click on the path, write "cmd" and press ⏎ Enter. This will open a windows command prompt in the current folder.

Then type in the following command and press ⏎ Enter:

blender -R

If it goes correctly, it should answer this:

Registering file extension...success (user)

You just need to close any windows explorer windows and open again to apply the changes.
Alternatively, you can also do this via the following command:

taskkill /f /im explorer.exe && start explorer.exe

Note that it will do the registration only for the current user. If you want to do it for the entire system:

open the start menu
type in "cmd"
right-click the command line tools
"run as administrator"
run the command chdir "C:/Program files/Blender Foundation/Blender"(change your blender path if needed)
run the command blender -R
run the command taskkill /f /im explorer.exe && start explorer.exe
voilà


Why is Blender so Slow for only one File?

You have enabled dupliframes, which is set to make 100 duplicates of your model giving your file a total of nearly 4.3 million vertices.

You can find this setting in the object properties under Duplication.


Preserving sub-group instances when making duplicates real

The following script works with the workflow in the question:

  make the new file, open it, link the group, select the group instance, then run a 'Make Source' script.

What the script does:

Takes the active object, which should be an externally linked DupliGroup.
Checks if the name of the DupliGroup already exists as a local group and stops the script if it does.
Stores DupliGroup name, and external library path.
Deletes the active object as it is not necessary anymore.
Links the objects from the library '.blend', then links them, makes a proxy object, then deletes the non-proxy objects.
Adds the proxy objects to a group with the same name as the DupliGroup.

Of course the script doesn't actually make this group the source, more would need to be added to do that. It just appends the contents of a group to a local group of the same name.

Forgive lack of convention in the code.

make_source.py, just run the script from Blender's internal text editor after selecting an externally linked DupliGroup:

# A class just for the purposes of stopping the script early without closing Blender.
class ExitWrongInput(Exception):
    def __init__(self, to_print):
        print("ExitWrongInput: %s" % to_print)

def link_external_group(library_path, group_name):
    # In this with statement, the data_to is just a list of strings, but after the with statement, it is actual data, which is what we return.
    with bpy.data.libraries.load(library_path, link=True) as (data_from, data_to):
        data_to.groups = [group_name]

    return data_to.groups[0]

def make_source():
    # Variable setup.
    # ----------
    scene = bpy.context.scene
    obj = scene.objects.active
    obj_dupligroup_name = obj.dupli_group.name

    # TODO Add a proper check to determine if the active is an externally linked DupliGroup object.

    # Check if the group already exists and exit the script if it does.
    for group_iter in bpy.data.groups:
        if (group_iter.name == obj_dupligroup_name) and (group_iter.library is None):
            raise ExitWrongInput('Group "%s" already exists.' % obj_dupligroup_name)

    libraries = bpy.data.libraries

    # Find library which the DupliGroup is in and store the path.
    obj_library_path = ""
    for library in libraries:
        for user in library.users_id:
            if user.name == obj_dupligroup_name:
                obj_library_path = library.filepath
                break
    # ----------

    # Delete obj.
    bpy.ops.object.delete()

    # Link the old source group to the scene.
    # ----------
    group_data = link_external_group(obj_library_path, obj_dupligroup_name)

    # No objects can be selected for the next part, so deselect all objects just in case.
    for obj_iter in bpy.data.objects:
        obj_iter.select = False

    # Link the objects to the scene then make proxies of them by making duplicate linked, and deleting the old ones.
    for obj_iter in group_data.objects:
        # Link the objects to the scene, it will not be possible to move them.
        linked_object = scene.objects.link(obj_iter)
        # Duplicate to a variable, not linked yet.
        duplicate_linked_obj = linked_object.object.copy()
        # Delete the old object that could not be moved.
        bpy.data.objects.remove(linked_object.object, True)
        # Link the new proxy object.
        duplicate_linked_obj = scene.objects.link(duplicate_linked_obj)
        # Add to selection for grouping.
        duplicate_linked_obj.select = True

    # Create new group from the selected objects.
    bpy.ops.group.create(name=obj_dupligroup_name)
    # ----------

    # Update the scene just in case.
    bpy.context.scene.update()

try:
    make_source()
except ExitWrongInput:
    pass


Is this expected behaviour for 'remove from all unlinked collections'?

Did you try dragging the orphaned object from the Outliner back into the 3D View?

sorry for the low quality


How to work with three point lighting system?

One method is to set the pivot center type to 3D Cursor, place the cursor wherever you like, select a plane, duplicate it (Shift+D) and rotate (R) along the Z axis by 90 degress (you may type a rotation value using your numerical keyboard).

The other method is using a Mirror Modifier. Choose the axis you want your plane to mirror and input the name of your illuminated object in a window under Mirror Object:. Then apply the modifier.

Go to Edit Mode, select all mirrored meshes (A), then press P-->Separate-->By Loose Parts to make them separate objects. Now select one of them, snap the cursor to the center of it (Shift+S-->Cursor to Selected). Enter the Object Mode and press Shift+Ctrl+Alt+C-->Origin to 3D Cursor to place the origin point within. Repeat the same process with other planes.

You may now adjust the transformations of the planes changing the transformation orientation type to Normal (tap G, R or S twice to make it work).


MS Process Explorer does not accurately report GPU usage.


What would be the best way to hollow out the space for nostrils while modelling a head?

There are many ways to do this. One way would be to just inset some faces and then extrude them towards inside.

You will probably want to edit the topology of your model using another modelling tools later to add more detail to the forms. That's why I would recommend watching some video tutorials about modelling.


If you need to animate your model you can try a simple trick: get a 2D image of a curtain with wrinkles, desaturate it, make it tileable and use it in "multiply" mode with the diffuse texture of your material.
This makes fake wrinkles that very often do the job!


How to get face normal from a mesh loop?

Loop the faces
Suggest this is easier to loop the faces and get the loop indices.
for f in mesh.polygons:
    print(f.index, f.loop_indices)

default cube
0 range(0, 4)
1 range(4, 8)
2 range(8, 12)
3 range(12, 16)
4 range(16, 20)
5 range(20, 24)


Create a stretchy line between two objects?

I couldn't get it to work with a curve as suggested by Greg Zaal, as you said the curve doesn't seem to want to stick to multiple hooks at once..

However it works fine for me using a mesh as explained in my previous answer, and it still runs realtime at 24 fps for me:

Example .blend


How to change the shadow color in Blender Cycles?

With the Cycles renderer enabled select the cube, give it a new material and set the material nodes as pictured below. Use the Is Camera Ray of the Light Path node as a factor for mixing the Diffuse and Transparent nodes (Is Shadow Ray works good as well).

Change the Hue, Saturation and Value values of the Transparent shader to change the shadow's color, intensity and transparency.

Here's the animated test using the changes mentioned above:


How do I color the shading of a material?

This is something you can do very easily in the Blender Internal renderer, where, unlike Cycles, you can feed the output of light's interaction with a surface back into the calculation.

In Cycles, this would lead to a feedback loop: (lighting affects surface affects lighting affects....), so there, you would have break the loop by baking the outcome of one light/surface interaction as, say, a diffuse texture,  and use it to influence a  second.

Simplest sort of node setup:

(You can use the shading output any way you like)

Result..

In Cycles, you could find a more physically-based route to a specific effect you were looking for .. perhaps subsurface scattering, translucency, fresnel...


IN the User Preferences, enable the Rigify addon (2.79) and then in the add menu under armature, you will find the other rigs.


how should i do, to get output file name in order?

After render.
If you have set the render file path such that it only contains the rendered images with that file extension, can run this script, from within the blender text editor,  after rendering.
import bpy
from pathlib import Path

op = 'RENAME' # to rename
#op = 'CLEAN' # to remove

context = bpy.context
scene = context.scene
render = scene.render
ext = render.file_extension

rfp = Path(render.filepath)
fldr = rfp if rfp.is_dir() else rfp.parent

for f in sorted(fldr.glob(f"*{ext}")):
    if op == 'CLEAN':
        f.unlink()
    elif op == 'RENAME':
        print(f.name, end=" -> ")
        num = int(f.stem) // scene.frame_step + 1
        f2 = fldr / f"{num : 05d}{ext}"
        if not f2.exists():
            f.rename(f2)
        print(f2.name)

Output after rename.
0001.png ->  0001.png
0005.png ->  0002.png
0009.png ->  0003.png
0013.png ->  0004.png
0017.png ->  0005.png


Use the Inset tool (keyboard shortcut i)

Set it to individual


Why does running a game engine script from the text editor cause an error?

The 'Run Script' button is not intended for BGE, but for Blender addons and macros. Understand that BGE is a standalone component, it's not part of Blender environment.

This way, importing the module bge is not possible when running scripts inside Blender, the same way you can't import the module bpy while running scripts through BGE.


How to retopologize asymetrical meshes not aligned to a global axis

Credit to Patrick on BlenderArtists.org for helping me find the solution. (https://blenderartists.org/t/how-do-i-retopologize-asymetrical-meshes-not-aligned-to-a-global-axis/1236449/3). The mirror modifier is local. My mistake was setting the retopology mesh origin as the center instead of the high poly mesh origin as the center. Also, my topology work above is pretty hamhanded. http://wiki.polycount.com/wiki/FaceTopology seems to have some nice color coded examples of how the flow is supposed to look on faces.


I would suggest to use a cloth + pressure (internal pressure) + pin group + collision objects if you want to add more geometry


First, I have edited your question because the term you were using in asking your question was not the right one. In fact, you were asking about loop cuts, not edge loops. The difference is that an edge loop is a set of existing edges linked end to end, while a loop cut defines a path upon which existing geometry will be modified to add a set of edges.

If you switch to vertex select mode, you'll see that the loop cut is interrupted because the two large faces just beyond where your desired loop cut ends in your screenshot are n-gons. There are six vertices around the perimiter, three on the top and three on the bottom of each face. A clue to this is the fact that in the right-most inset faces, in face select mode, the squares designating the center of mass of the faces is offset to the right, when compared with the other three.


Can you toggle on/off the physical properties of a mesh?

In the physics tab there is an option to set the physics to "Ghost" which is a quick way to disable physics without changing any collision parameters you may have set up.

As for hiding the object, in the Outliner View find your object's listing and click the little eye icon. This disables the rendering of the object in the viewport and in the final render/game.

To make the object reappear and enable its physics again simply toggle the listed options again. :)


Way to transport setting of file browser to new version of blender

(I have found way by myself)
In your drive, such as:
C:\Users(Username)\AppData\Roaming\Blender Foundation\Blender\2.82\config
you have three text-files that stores file browser information. copy and paste will do the work.


blender is not using the GPU as my graphics card

The intel 520 is an integrated graphics chip, which means it resides on, and shares power with, the CPU.  You're better off using CPU on this machine.
The total available memory is your 8GB RAM plus 128 MB dedicated for video.


Now the 2.81 has been released and unfortunately collection visibility animation still not supported. So you have to use some tricky solution which are not as good as expected.

The first method (first two pictures):

Animate one of the object's visibilty with the traditional way: turn it on/off and hover the mouse above the camera icon and press "i" at the right frame.
Select every object what you want to hide, the animated must be the active (yellow outline) and hit CTRL+L, then choose "Animation Data"

Now every object has the same animation, so the big disadvantage of this method, they can't have location/rotation/scale animation, because all of them will be the same. But if you can lack these, this is a simple solution.

Second method (last picture):

The collection must be out of the camera view and visible for render. Add an empty (make sure it's not part of the collection) in front of the camera and add the collection as an instance of the empty (it's located in the object properties). Now the empty will shows a copy of the whole collection and you can hide it all by hiding the Empty (what you can animate of course). With this method you can animate the objects independently, but not in the real space.

So both method have disadvantages, so we hope the collection visibility animation will arrive soon.


Here may be an alternative to Metaballs, I remember seeing something similar done with 3DS Maxs symmetry modifier so I attempted to try something with Blenders mirror modifier in combination with other modifiers.

On your mesh that you want to split go into edit mode and select some vertices where you want there to be tension during the animation and apply a hook modifier then a mirror modifier (use a empty for your mirror modifier origin) and then apply some smooth and sub D modifiers towards the end. Maybe the animation can be baked and then soft body dynamics could be applied but I've never tried that though, just a thought.


No that would not work, you can only link non linked objects (so just the objects you made) in the file you want to link.


Learning Rigid Body Constraints (Slider & Piston) - Active object keeps passing through passive?

You are trying to get the objects 'Active1' and 'Passive (connected to Active1)' to collide. These two objects share a rigid body constraint through the empty 'Piston Constraint.' This constraint has 'Disable Collisions' checked. This is telling Bullet to ignore 'Active1' and 'Passive (connected to Active1)' collisions.


How do I stop the object I used as part of a boolean from rendering?

You need to disable the rendering of your object:

in the outliner menu on the right, click on to enable the rendering toggle switch

then just turn it off for your object.


I guess the standard advice of making mesh light sources brighter and spot lamp sizes larger applies here, these would be the most "natural" ways of reducing noise[1].

If the Starmap is emitting light as an HDR, it might be a good idea to try Multiple Importance Sampling in Cycles.

But I do agree with you that one should expect a less noisy image at 3000 samples. Filmic blender actually doesn't affect Cycles contrary to popular belief.

Also, have a look at airenderer.com. It's a renderer that takes a noisy image (probably 200 samples is enough here) and gives you a more rendered result. It doesn't every type of scene well, but this looks like the type of scene this was built for.

sources: [1]blenderguru.com


Fixing normals without getting in edit mode

As far as I think that @bertmoog could be right I will try to answer your question and propose Add-on called Flippist from Alexey Khlystov.

Download Add-on from link above and install/enable it as usual.
Select one (or multiple) object.
Hit Spacebar, then type Flippist.
You can change settings by pressing F6 or in Tool Shelf.


How to keep the circular part of the cone a circle whilst bending the rest?

The simple answer is, the warp tool only works on selected vertices, so you could in theory leave the back ring of vertices of your cone unselected.  However, assuming you're using the method by @Haunt_House in this answer, I am not sure you will find the results satisfactory, because there will be a strangely shaped discontinuity between the warped and unwarped vertices.

Instead I think you might be better served by cleanly chopping off the back portion of your transformed cylinder.  There are a couple of ways you could do this.  You could create a cube and use the Boolean modifier in "Difference" mode:

Or, in edit mode, you could create a plane and scale and orient it for correct chopping:

Then position the plane where you want to make the cut:

Then select all vertices and choose Mesh-->Faces-->Intersect (Knife) and make sure the source is set to "Self Intersect" and the separate mode is set to "Cut".  This will result in a divided geometry in which you can move or delete unneeded sections (I have deleted the plane in the screenshots below because it is no longer needed):


Smoke Simulation is different in 3D viewport from final render

Although the quick smoke feature creates the texture nodes for the smoke, it doesn't for the flames.  So when you render it, only the smoke is visible.

This has been covered before on Blender StackExchange:

https://blender.stackexchange.com/questions/55777/fire-showing-in-viewport-not-in-render

This is also covered in Blender Guru's fire tutorial:

Blender Guru - Fire


You can duplicate the cloth object in an animated state (there is an addon called Corrective shape keys) where vertices are already in a "clothy" way. You can then use this as a base for other animations. The problem is: The cloth modifier still takes some frames of jiggling before it is stead


How can I use Filter nodes from Compositor in Material Editor?

Unfortunately, compositing nodes and shader nodes are not interchangeable.

There are some new shader nodes available in the 2.81 release, which include extra vector math and the ability to connect inputs to the mapping node.

If these are not adaptable to your needs, you will need to do what you want in the compositor. Using cycles, you can use the object and material indices to get a mask in the compositor allowing you to apply the dilate to a specific object/s.

While the object and material indices are not currently available in evee when compositing, they are available in the object info shader node. You could use layers to have one object separated from the scene so you can adjust it in the compositor before combining it into the final image.


You need only one vertex for it. Select this vertex. In the Screw modifier tab make an empty your AxisOb, select an axis and set the remaining params as required. By the way, you can apply this modifier to any object, such as a  circle.


How do I stop my texture from stretching when I pose my character?

In real the material on the knee would be either

compressed when the knee is straight and normal when it is bent ... or ...
normal when the knee is straight and stretched when the knee is bent.

If you want to "float" it out of thin air, you need to hide some extra geometry below the surface, like pi75 mentioned in the comment above.
Proof of concept


How to add an Empty to all selected objects?

For Blender >2.80 this will work.
Select all your objects and run this in the scripting panel.
import bpy

for object in bpy.context.selected_objects:
    obj_loc = object.location
    new_empty = bpy.data.objects.new( "empty", None )
    new_empty.location = obj_loc
    object.parent = new_empty # swap this line around to parent the other way
    object.matrix_world = object.matrix_parent_inverse
    bpy.context.scene.collection.objects.link( new_empty )

This will create new emptys at the object origins of all the selected objects, parent the object to the empty and remove any offset between the object and the empty.


How do I make various objects point at/follow a path?

You can definitely use a path.

 RMB select the first house and add two constraints.

A Follow Path constraint. Choose the Curve object as the target. Then check Follow Curve and Fixed Position. The offset has to vary for each object, for the first object we will leave it at 0.0.
A Limit Rotation constraint. Check Limit X and Limit Y. This prevents objects from tilting sideways. We only need the Z rotation.

⇧ Shift RMBSelect all other houses, lastly add the constrained object to the selection. Copy the constraints to all houses by going to Objects > Constraints > Copy Constraints to Selected Objects.
Adjust the Offset value for each house. E.g. [0, 0.25, 0.5, 0.75, 1]


I was not able to find a way to cut the edges off, but I was able to find a decent substitute: Weight Painting. This is the result I produced:

With your mouse in the 3D viewport, key Tab to enter edit mode. Key W and select Subdivide 3-5 times (the more the better, until it lags to much).

Next, key Tab followed by Ctrl + Tab to enter weight painting mode. Go to the Tools bar. Make sure Weight: is set to 1. Paint a streak down the middle of the lateral faces and a dot on each end by dragging the mouse while holding the left button down. Your result should look something like this (mirrored on the hidden sides):

Note that I moved the emmission time to 5 frames so that I could paint in peace.

Lastly, go to your particle system settings, the Vertex Groups drop down and the Density: option. Select Group (it should be the only group there). Here is the modified .blend file. I might fiddle with the painting and size of the emitted particles to get a nicer looking result.


How to delete faces with only one edge connected to mesh?

Bmesh script.

There may be a way via one of the selection items in the UI, however will propose a script solution
Selecting
Run over all faces in the edit mesh, and if all face edges, or all but one face edge are boundary select the face.
import bpy
import bmesh
from bpy import context

ob = context.edit_object
me = ob.data
bm = bmesh.from_edit_mesh(me)
for f in bm.faces:
    f.select_set(len([e for e in f.edges if e.is_boundary]) >= len(f.edges) - 1)
bmesh.update_edit_mesh(me)

Deleting
Similarly, while there are faces, find the "tabs", and if any remove their boundary edges, repeat until can find no more, or all faces removed.
import bpy
import bmesh
from bpy import context

ob = context.edit_object
me = ob.data
bm = bmesh.from_edit_mesh(me)
while bm.faces:
    faces = [f for f in bm.faces if (len([e for e in f.edges if e.is_boundary]) >= len(f.edges) - 1)]
    if not faces:
        break

    edges = list(set(e for f in faces for e in f.edges if e.is_boundary))
    bmesh.ops.delete(
            bm,
            geom=edges,
            context='EDGES',
            )
bmesh.update_edit_mesh(me)


Use Match Texture space on the curve.

Then set your coordinates to Object.

You need then to adjust size and offset a bit.


How can i make a low poly flame animation in Blender

I took a quick stab at this with a Sculpted mesh using Dynotopo symmetry off with a pixel setting of 12.

The rest was done with just animating an empty, and using that empty as the referenced object in a displacement modifier with a magic texture.

This was about 10 minutes worth of work if you happen to be efficient in Blender.

Hence I'm sure you could spend a little more time if you want it to look as good as it does in your reference.

I would imagine that an animated loop of upward flying diamond shapes at the same speed and the same material would sell the flying ember effect.

Here's the fruit of my 10 minutes (the difference between the two are texture selection & empty animation differences only):

Attempt #1:

Attempt #2:

Per request here is the Blend File:
I've also included an action within it for you associated to a "Fake" user.
As of Right now, the animation wont start until you hit frame 15.
In the NLA editor just drag the action back to the beginning frame (highlight it and hit G >> Drag to the left) to watch the full animation from the start.

As for a sprite sheet, I really recommend watching the video I linked to in the comments.

Here is a Sprite sheet that I rendered out from this file:


You could try something like this (bump mapped material option).

I just used a couple of noise textures mixed together to make a randomly patchy surface. I used a mapping node to stretch (scale) it a bit to make it longer like grass. I used the mix  as the basis for a bump map. The reason I ran them through a MixRGB mixed with white first, is to soften the contrast, which would give to strong of a "bump effect" otherwise. Even after doing this, I still had to reduce the "distance" on the Bump Node. I also used a third noise texture  which I used as a mix factor for the "main grass colors". You can control the mix by sliding the sliders on the ColorRamp.

I used an Ambient Occlusion node to give extra dark (shaded) patches, as well as to add a bit of a darker blue accent color. This can also be controlled by the ColorRamp. Usually, when using an Ambient Occlusion node, you should enable "Ambient Occlusion" in the render properties panel to get the full effect, but in this case, the "full effect" comes out too dark without further manipulation, so I left it unchecked. The node itself still provides values that can be used.

Lastly, I turned up the roughness and turned down the specular reflections to make it less "shiny". These may need to be adjusted to better suit your "model".
This is just a simple approximation of a grass shader, you can get much more detailed if necessary, this is just a starting example. I'll include the .blend file so you can play around with it without having to set it all up again yourself. Hopefully you can manipulate it successfully to your liking.
File is here -


Blender 2.8 I want to select the vertices, edges and faces that are on the front ONLY

There are several approaches you could take.
Note: So far as I can find, the backface culling options don't seem to do the trick. The one in the Materials tab, under the Settings section, would seem to only affect the appearance of backfaces during rendering. But there is another Backface Culling option located under the Viewport Shading menu at the top right of the 3D View, and it is only accessible if you happen to be in Solid shading mode at the moment. Clicking the Backface Culling checkbox here makes the backfaces change to translucent, but doesn't prevent their selection. One could be forgiven for expecting either of these options to prevent selection of backfaces, but neither do. The latter doesn't seem to do anything.
Thankfully, there are other approaches.

By default, your objects in a new scene are in solid shade mode. When
you go into Edit Mode for any object, it is likewise solid shaded by
default. If you go into Wireframe shading mode for the object while
it is in Edit Mode, you will see through the object, and be able to
select vertices on both sides. But if you press Alt +
z, you will toggle the X-ray feature for the mesh. This
feature works in both Object Mode and Edit Mode. In Edit Mode, it
forces an opaque view of the mesh in wireframe shading mode, where
normally, it would be transparent when the wireframe shows. This can
help prevent vertex selections to the rear of the mesh.
Alternatively, you can press Alt + b at any
time and then drag a box to create a View Clipping boundary, which
can be used to coral any parts that you want exclusively visible, meaning it instantly hides everything outside the boundary from
view. Pressing Alt + b again gets rid of the boundary.
Another interesting thing to note: For addressing this kind of issue specifically
during dyntopo, there is a common workflow in Blender where one
temporarily adds a Solidify modifier to the main mesh. The reason
for this is that the Solidify modifier simulates the existence of
both an outer shell facing and an inner shell facing, which includes
the simulated behavior of face normals. By having a Solidify modifier
in place, then when going into Edit Mode, the inner shell on the opposite side of the object
behaves as if it were an outer shell instead. This tricks
Blender into ignoring those faces during selection, effectively
giving you backface culling in Edit Mode even if you can't get it any
other way.


How to show missing edges with Freestyle edge mode?

Yes.

The edge disappears because it is no longer visible. This is more obvious on a shaded model:

If you want freestyle edges to be visible at all times, disable selection by visibility:


Convert Space

An example of using Object.convert_space  to test.  Add a bone constraint, run script in pose mode with at least one pose bone selected. Should see that the bone remains in place and all constraint influences are zeroed. Note have used the default quaternion rotation

import bpy
context = bpy.context
ob = context.object

for pb in context.selected_pose_bones_from_active_object:
    M = ob.convert_space(
            pose_bone=pb,
            matrix=pb.matrix,
            from_space='POSE',
            to_space='LOCAL_WITH_PARENT',
            )

    if pb.constraints:
        for c in pb.constraints:
            c.influence = 0
        loc, rot, scale = M.decompose()
        pb.location = loc
        pb.rotation_quaternion = rot
        pb.scale = scale

Baking to fcurve

Similarly will set frames for each in scene frame range, and store the matrix calculated as above for each frame for each selected pose bone.

Then create an action, and keyframe it from the data.  I have only added location

import bpy
import numpy as np
from collections import defaultdict

context = bpy.context
scene = context.scene
ob = context.object
frames = np.arange(scene.frame_start, scene.frame_end + 1)

data = defaultdict(list)

for f in frames:
    scene.frame_set(f)
    for pb in context.selected_pose_bones_from_active_object:

        M = ob.convert_space(
                pose_bone=pb,
                matrix=pb.matrix,
                from_space='POSE',
                to_space='LOCAL_WITH_PARENT',
                )
        data[pb].append(M)

action = bpy.data.actions.new(f"{ob.name}_BAKE")
action.id_root = 'OBJECT'

fcurves = action.fcurves

def flatten(a, b):
    c = np.empty((a.size + b.size,), dtype=b.dtype)
    c[0::2] = a
    c[1::2] = b
    return c

for pb, mats in data.items():
    # remove or de-infuence constraints
    for c in pb.constraints:
        c.influence = 0
    locs = np.array([M.translation for M in mats]).T
    for i, d in enumerate(locs):
        fc = fcurves.new(pb.path_from_id("location"), index=i, action_group="Bake")
        fc.keyframe_points.add(len(frames))
        fc.keyframe_points.foreach_set("co", flatten(frames, locs[i]))
    # similarly as above for rots etc..
    rots = np.array([M.to_euler() for M in mats]).T

ob.animation_data_create()
ob.animation_data.action = action

Note  tested this with constraints rather than NLA stack, in concept "should" be the same and create one animation based on visual transform.  Might need to ob.animation_data.use_nla = False to turn off the influence of NLA. (Similar to setting constraint influences)

Note the flatten method was quickest method suggested here https://stackoverflow.com/questions/5347065/interweaving-two-numpy-arrays


you can use the "f" hotkey to fill in any edges or vertexes you have selected, you could try that and see if it works.


If you don't want to change the real selection states, you may wanna use an override:

import bpy

scene = bpy.context.scene

obs = []
for ob in scene.objects:
    # whatever objects you want to join...
    if ob.type == 'MESH':
        obs.append(ob)

ctx = bpy.context.copy()

# one of the objects to join
ctx['active_object'] = obs[0]

ctx['selected_objects'] = obs
# In Blender 2.8x this needs to be the following instead:
#ctx['selected_editable_objects'] = obs

# We need the scene bases as well for joining.
# Remove this line in Blender >= 2.80!
ctx['selected_editable_bases'] = [scene.object_bases[ob.name] for ob in obs]

bpy.ops.object.join(ctx)


Flip normals or delete geometry? For better overall performance

As a simple, yet very true rule in game design:
- Remove anything the player will never see or use.

UV data is still loaded, vertices are still calculated, there is still a check to see if the face is visible. Everything except the final step, which is 'visualising the face'.


What is the best way to make these wire wraps around a mesh?

I don't know if there's a "procedural" way to do it, but you could do it manually this way:

Once your body is ready, create a second mesh (plane) over the body.
Activate the Snap / Face mode, with all its options enabled.
Begin to extrude your plane to make your straps. As the Snap is enabled, the vertices will stick to the body underneath.
When you'll have finished you can add a Solidify modifier to give thickness, a Bevel modifier to make the angles round, then a Subdivision Surface modifier to smooth (+ press the Smooth Shading button on the Tools panel > Tools > Edit > Shading.
Add some edge loops to your straps to give them more angular angles.


This can be found in the Text Editor, selectable from the bottom left of the 3D view.  You have to select OperatorList.txt from the list of open documents.

NB.  If you want the file to persist you have to save it as a .txt file (Shift + Ctrl + Alt + S).


Merge by distance should fix your problem, but you need to select the entire model. If it still doesn't work try increasing the merge distance.

Try identifying of which vertices you have duplicates by using the box select tool on one of them and paying attention to the bottom left of the window. If it says "Verts: 2/13" you press "alt + m" and click on "at center". Repeat this until all duplicates are gone.


Why does Subdivide Smooth look different when compared to the Subsurf modifier?

When using subdivision in edit mode, the original vertices stay at the exact same place. The rest of the mesh swells up around it.

When using the modifier, vertices and edges are more like control points of a nurbs curve. The image below illustrates it. Note that concave shapes (the thinner section of the model below) will swell outwards.

It's not possible to make a truly spherical shape when using subsurf, but the more verts you have in the original mesh, the less noticeable the irregularities will be and the more spherical it will look. You can also use a Shinkwrap modifier to "project" your mesh onto a real sphere, or a Cast modifier or the To Sphere (Alt+Shift+S) operator to warp it into shape. I often do this when wanting a mesh that can be subdivided but still have a nice equator.


Pivot point changes location between Edit and Object mode

The issue is that you are using the Median Point as the Pivot Point to to rotate. Select 3D Cursor:

Here are some of the differences using different pivot points:


Your 'Fake Glass' using a single plane instead of a solid works as expected when the plane is viewed from the 'front' side (the side that the normal is facing) but the Fresnel node produces different results when viewed from the 'back'. In order to correct for this you need to adjust the IOR to 1/IOR when viewing the surface from the 'back' and this can be achieved as follows :

Here the Backfacing geometry node controls the Mix between IOR and 1/IOR so that when viewed from the 'back' of the surface it still behaves the same as from the 'front'.

Replace the Fresnel node in your example with the above nodes and this should resolve your problem.


Keyframes not setting where I place them

Oh ok I've found out, you need to go in the Properties panel > Render > Dimensions > Time Remapping, and choose 100 / 100


maximum precision allowable in Cycles Nodes (decimals)

Simply type in the desired value in your color ramp node. The most precise I was able to achieve before Blender made it zero was 0.0000001.


How do I create new objects from a mesh created from animation nodes?

Use the Object Instancer node to create n empty objects where n is the number of meshes you have. Then loop over both meshes and the empty objects and write each mesh to each empty object using the Mesh Object Output node. For example:

Notice how each mesh is its own object.


Joining rooms made with archimesh creates one sided model

Archimesh uses a so called solidify-modifier to make your walls thick (instead of "real" geometry that you can manipulate in edit mode)

you have multiple options to change the materials:

you can apply the modifier: go to the panel on the right and click on the blue wrench icon. there you can click apply (green box in the screenshot)
you can enter a material index offset of "1" in the modifier panel and simply add a second material to you walls


How to AddDriver the rotation value of the armature for the rotation value of the object

In the drivers editor, variable tab, instead of "single property" use "transform channel" ( (X) Symbol), then choose your bone, choose X rotation with auto euler option, choose world or local space, and when rotating the bone in pose mode, X rotation of the cube will follow.


Save image as for example .png by a script

You can try to use a low-level method. The Image class is documented
here.

The file format is stored in the attribute
Image.file_format.

The Image class offers two methods to save images:

save()
save_render(filepath,scene=None)

So you can probably save your image like this:

scene=bpy.context.scene
scene.render.image_settings.file_format='BMP'
image.save_render(filepath,scene)

You might try:

image.file_format='BMP'
bpy.ops.image.save_as({'area': imageEditorArea}, # emulate an imageEditor
    'INVOKE_DEFAULT', # invoke the operator
    copy=True, # make a copy of the image
    filepath=exportDir + image.name) # export it to this location


Is it possible to lock a bone in pose mode while removing the influence from the parent?

Possibly the most straightforward way to do what you want is to use a Child Of constraint. It works just like parenting, except that its effect can be keyframed, unlike actual parenting. So it can be turned on or off at will.
Begin by selecting your armature and then going into Edit Mode, then selecting the child bone in the chain you want to be pinned. Alt + p to bring up the Unparent menu, then Clear Parent. Now go into Pose Mode. The newly liberated child bone should still be selected. If not, select it. Go to the Bone Constraints Tab in the Properties Panel, and create a Child Of constraint from the Constraints dropdown. Specify the armature as the target for this constraint, then the parent bone, by name, also in the associated field (there are two text fields for the target when the target is part of an armature. The first text field is for the armature itself, and the second is for the bone within that armature which you specifically want to target). Now your child bone should move as a child while your parent is selected and rotated. When you are ready to turn off the constraint, look in the Constraint properties for the Influence slider. Right-click on it and set a keyframe. Do this on the frame just before you want it turned off. Advance the frame by one, and then slide the influence bar to zero. Then set another keyframe. Your child bone will now behave as if it is not parented.
This may or may not work ideally depending on whatever your exact situation is. But it definitely overcomes the problem of needing a parenting relationship on and off on the fly while animating.


Is it possible to switch from 2D Animation context to General context in Blender 2.8?

If you click the + icon at the end of the row of available workspaces, you will get a drop-down menu with all the other workspaces not currently in the menu.


What is the best way to add more than one bvh file actions in a makehuman model?

Since you know how to load and retarget a bvh animation, i will try to explain how to use the nla editor to play some actions in a sequence

First you might want to open a dopesheet editor and set its mode to Action Editor. Every time you load a BVH animation the current action gets replaced by a new action. However every action uses the fake user (the background of the  F-Button is darkened) and thus remains in the blend file even when its saved and reloaded.

By clicking  in the second highlighted box you can choose the current action for your animation. When you are done and loaded all animations you want to enqueue, press the  button to the right to unlink the action from the armature. It should look like this.

Now open the NLA editor. You can also choose and unlink the action in the Properties Panel (Press N to toggle it)

Choose Add -> Add Tracks from the Menu below. Move the cursor(green line) to frame 0 (click and drag) and choose Add -> Add Action Strip where you choose your action you want to play first from the dropdown menu. Move the cursor beyond the yellow bar representing the action strip and add your next strip.

It should look like this afterwards

You can add additional tracks and stack them. The options for blending the strips can be found in the Properties Panel

You might want to create your own actions and only keyframe specific parts like the root bone and put it on top of the stack to override and control the motion.

For further informations see NLA Editor. Here is a link to a video showing the steps described above.


Split a plane into smaller plane objects

Manual and slow approach

Select the object and go into edit mode, using Tab
Subdivide the plane into any number of smaller faces using W -> S repeatedly
Click face select  or do Ctrl + Tab -> F
Proceed to select each face in the plane, the press P + Enter to split the plane into separate objects

UPDATE: Automatic and fast approach

Instead of having to go through each face manually, you can do everything in one sweep like this:

Instead of starting with a plane, create a Grid object with Shift + A -> M -> G. Then go into edit mode, using Tab.
Select all faces with A and do Ctrl + E -> D (edge split). Now all of your faces are disconnected.
Select all faces with A and do P -> L. This separated all the faces by loose parts, into separate objects.


How to render an animation through command prompt in Cycles?

one way to achieve this is to change your output settings in your project -> file format -> video.
Then use your command in command prompt.


Decimal places in RGBA values of Python-generated image?

Images are usually created and packed as PNGs as 8-bit sRGB format. This severely limits the precision of the RGBA values stored. To improve precision you need to force the image to be stored in a format that supports 32-bit float channels such as EXR format.

To use a simple example, storing as an 8-bit image would be limited to steps of 1/256 or approximately 0.0039 - any value below around 0.002 would be rounded down to zero and any value from 0.002 to around 0.006 would be rounded to 0.004 (or 00000001 in binary). The actual values used for each 'step' is further complicated by the sRGB color conversion (which stretches the color space in order to produce a more practical range of colors for display on a screen - see Wikipedia sRGB

Examples of storing images in 32-bit float EXR format can be found in Creating and packing a 32-bit float image and Capture object properties to use in a Cycles material


How do you allow inertia in bones for animating in pose mode?

What you want is currently not (simply) available as far as i know.
When animating on the right there is options, there you could enable AutoIk.
Together width that i would use helper empties. So you can set Bone constrains so that for example the feed take 100 height influence of the surfboard, and the hip takes 30%... but it might not realy look 'elastic movement' that way. This is currently still mostly the art of animating.

Perhaps if your handy with python script you could automate the movement or the influence of the helper empties a bit.

Tough yet alone using empty constrains on bones to set their position can reduce work time (if the autoIK bones wont bend wrongly (fix width more constrains)..). Animating by such empties usually does give a better result.


Creating bmesh from an object: why is scale ignored?

This is NOT a bug.

The bmesh module provides access to blender's mesh data structures.

The bmesh is created from the mesh using its local coordinates.  What object or objects it is linked to, and their object transformations,  is immaterial.  The mesh may also be linked to no objects.

For example. Python console code. The cube mesh linked to cube object in default scene

>>> C.object.data
bpy.data.meshes['Cube']

there is no difference between creating a from mesh bmesh passing C.object.data or bpy.data.meshes["Cube"] as the mesh argument.

To transform the bmesh to global coordinates, based on its linked object obj

bm = bmesh.new()
bm.from_mesh(obj.data)
bmesh.ops.transform(bm, matrix=obj.matrix_world, verts=bm.verts)

If you require the deformation modifiers assigned to object applied to the bmesh, use bm.from_object(...). However this will also not apply any object transformations (loc, rot, scale) to the coordinate data of the bmesh either, and will need to be done separately as shown above as well.


What's the name of the keystroke that the streamer uses?

Is ScreenCastKeys (from github you can get it, but there is other versions, but that's the name "ScreenCastKeys" there is a compatible version for 2.9, but I don't know if its ready for 2.91)


Does Blender 2.8 require microsoft access database 2010 to run?

No.  Blender is built on open technologies which are also available on non-microsoft platforms.  Therefore it cannot depend on anything more than a basic install of Windows and of course, relevant graphics drivers.


Your mesh is super messy and has too many double vertices, which means vertices overlaying other vertices at the same position or too close to. You must select your object, go in Edit mode, select all and W > Remove Doubles. On the bottom of the Tools panel (activated with T), on the left of your 3D view, you can change the Merge Distance, choose 1cm.

Now you can parent the mesh to the armature.

But note that the Automatic Weight mode is not the good one for this kind of object, as this is not an organic but a mechanic object. You should rather choose With Empty Groups, which will create in your object as many vertex groups as you have bones, but without assigning them to any part of the mesh ("empty groups").

First you need to separate your mesh in several parts (well, it will be very hard with your topology, I suggest you redo it from scratch). Then parent With Empty Groups. To assign each part of the mesh to the right group, go in the Properties panel of the object > Data > Vertex Groups, select the part of the mesh you want, select the vertex group it is supposed to be part of in the list, and click Assign.


MixRGB node should do it for you. Connect the alpha from the image with transparency and use it as a mix factor.


I think it's worth reproducing Ton's statement on this issue here:

A lot of (really great) UI design proposals that went on the past week give quite a false impression that it’s either feasible to just replace the UI, or that its possible to pay for it – even when it takes a dozen people a year to work on.
The misconception here is that the “UI” is some kind of separated entity of a program, which can just be peeled off and replaced with another interface. However, a really good UI (and certainly Blender’s) is not just an abstract independent layer, it’s the reflection (and sometimes even the core) of the program’s design.
You can easily state that a significant part of the Blender code (more than a quarter) is “the interface”. You cannot code any tool without understanding “the UI”. You cannot work on compositing or rendering without keeping track of it. A particle system is “UI”. How animation systems relate is “UI”. How files read and write is “UI”. The way how undo works is even “UI”.
So – replacing a UI can be as impossible as trying to replace the script in a film. Let’s not go that way now. A full rewrite of Blender might happen once, but I think we have enough quality code design in Blender still – and a whole lot of open todo topics – to fill at least several years of coding time with.


Agreed, it is odd, that the FoV is not keyframeable. However, you can just switch it to "Millimeters" instead of "Field of View".


Press G, G or Ctrl E > Edge Slide to move the loop cut. Then in the bottom of the Tool Shelf or by pressing F6 turn on Correct UVs.

In Blender 2.9 it's now called Correct Face Attributes


How can you use color ramp to affect emissive shader

That can be done using the geometry input node and doing that you'll have to tune the Z value depending on the object geometry:

The node math is done this way, as in this example Z is going from -1 to +1. So dividing by 2 obtains something between -0.5 and +0.5 and add 0.5 obtains something between 0 and 1 which is what we want for the colorramp.

You can also use a UV map (to avoid geometric calculation). For instance make the UV map with 'project from view (bounds)', so that you can:


Ok. I played some with your model. It seems during modeling some edges became corrupt. What you need to do is select all the offending edges, that should be smoothed by SDS but are not, one by one, hit X choose Dissolve Edge, then select the 2 remaining Vertices and hit J. What you will be doing is in fact replacing all erronous existing edges with new ones. Then they become smooth under SDS. Then you can apply Crease to all the needed edges. It's a laborious task, but it works. You need to rebuild all the corrupt edges one by one.

Here I rebuilt 2 edges, as an example.


I added a bump to a material, but the color doesn't seem right

The problem you are having is being caused by the fact that you have three shaders, but only one is influenced by the image texture.

Plug your colour map (top image texture) into the colour input of the other diffuse shader and the glossy shader.


I want to make the muscles pump like a heart (Resident Evil 4 Final Monster)

I'd probably do it using shape keys:
Blender Character Animation: Shape Keys


This is how I would do it:

Create a bezier curve for the in the shape of the handle's profile. Life is easier if you put the object's origin at one end.

Create another curve in the shape of the handle.  To simplify things, I left the origin at the World Center and used a mirror modifier.

With the handle shape selected, go into the Curve properties, Geometry section and create a bevel, using the profile curve as the bevel object.

That should give you the basic geometry.  You could convert to mesh, add a solidify modifier and make any tweaks you wanted from there.


Can I move the items that I have already copied in Array?

you might apply the array, so it becomes one large object, then separate object in edit mode press P loose parts, now you can re-position all separated objects.


In this case, you have a simple problem of missing faces. One way to verify this is to install the MeshLint addon for Blender. Then use the "Check Non-manifold Elements" tool. This will find any holes in your mesh.

To fix the holes, select the edges around one hole and press F. And repeat for any remaining holes.

Other common mesh problems can be fixed by removing vertices that share the same space. Called doubles. To do so, press W and select Remove Doubles.


The selection of the mesh is disabled, you need to enable it first. It's a 2.79 blend file and for some reason, the materials are not shown correctly in Blender 2.8+. But you can recreate them:

Add the Shading workspace: [+] → Sculpting → Shading
Click the Filter icon, and select the first 5 Restriction Toggles. This includes Selection, the arrow icon.
The mesh is parented to the armature. Expand it and look for CSGOMotogloves. Activate Selection (arrow icon). Now you can select the mesh. Select it.
Materials exist already. Select one to recreate
Check Use Nodes in the shading editor
Add the Image Texture nodes and the Normal Map node. Select the images for the Image Texture nodes. Don't forget to set Color Space to Non-Color for the normal map image.

Repeat steps 4 to 6 for the remaining 2 materials. That's it :-)


Binary rounding errors are possible if the values used are very small or very large, or have a lot of significant figures. Blender uses 32bit floats to store values, so it is very possible to observe binary rounding errors in Blender in some cases. However I believe this is more likely because of the unwrapping algorythm used(maybe binary rounding errors are more visible when using it - I am not sure). If you try choosing Conformal instead of Angle Based this will probably solve the issue:


How do I reset a specific bone's "Stretch To" Rest Length, via code?

When running from the properties constraints panel context.constraint is defined.  To run in script elsewhere we need to override context ie add constraint to the context dictionary and pass it to the operator.

c = context.copy()  # copy the context returns dic.
# add constraint to the context dictionary
c["constraint"] = context.active_pose_bone.constraints['Stretch To']
# override context by passing dic as first argument
bpy.ops.constraint.stretchto_reset(c, constraint="Stretch To", owner='BONE')

Note: the code above is using the selected and active pose bone. There are numerous otherways to select and send a particular pose bone to the operator.


How do you visualize changes animations in the graph editor?

The graph editor displays what a keyframed value is set to at every frame. Left to right represents the frame of the animation while up and down represents the animated value.

An fcurve can be directly compared to a bezier curve, in fact that is what it is. The position of the curve as it is drawn at a certain point represents the frame and value that will be used.

Here we see the x location of a cube. On frame one it is 0.0 and at frame six it is 5.0. As the curve is set to linear interpolation we see that it will be an even movement every frame from start to the end.

Now if we change the interpolation to bezier and adjust the handles we can get a different curve. Here the cube stays close to the start position until frame four and very quickly moves to the final position only in the last couple of frames.

Now looking at this curve, you can see the x location goes past and then back to the final position.

And here is the curve with a noise modifier added, can you "see" where the cube will be on each frame?

So you don't really "see" the movement, what you get is an understanding of how it moves in between two values. So you watch the animation changing in the viewport, then when something looks odd you can often see and remove the glitch in the curve that is making it move the wrong way. With enough experience you may even be able to pick out a bad fcurve without watching the animation.


Grass Particle System How do I do this without a base?

If you select the base mesh and go to the object modifiers tab, the particle system is there. If you then hit convert then it should duplicate the grass into a separate model, where then you could delete the base.


Parent object to mirrored side of object

That can be done with some constraints:

Place an empty has child of the original cube. This is to place Suzanne relatively to the cube.
Then add two "transformation" constraints to Suzanne, with the above empty as target.

Presuming the mirror is on X.
One constraint for the locations, inverting X source (maps -1/1 to 1/-1).
One constraint for the rotations, inverting Y and Z source either (the same way).


Legally switching from 3DsMax to Blender

I have unfamiliar with the any license or Terms of Service agreement of any edition of 3DS Max, and I am not a lawyer, and don't play one on the internet.

Having made those disclaimers, it is my understanding that the producers or Vendors of a software program do not have any legal interest in any output file (in this case a mesh) that you produce with your software. Just as Micro$oft does not have any intellectual property rights in a novel you create with their word processing software, the purveyors of 3DS Mas probably do not have any intellectual property rights in your meshes. The only exception of which I am aware to this general principle is if the file format to which you are exporting is proprietary, in which case the file format might be copyright. But even then, while the file format might be subject to copyright, that copyright applies to the file format, not the file content.

However, the format to which you expect to export, ~.obj, is an open format, and is not controlled by the purveyors of 3DS Max, so there is unlikely to be any associated licensing data.

ns


What Mzidare said was right. I went back to the project today, and tried again. Yes, you can select the ball separately and move it to another layer just like you would if the group was not linked. I tried it with the ball included in the group I linked and with it not in the group and I had the same result. I was pretty sure that I had tried that before, but I guess I must have done something wrong.  Mzidare, if you want you can re-post your comment as an answer and I'll up-vote it.


Why is this mirror object not reflecting light onto another surface properly?

The roughness setting is insanely low, which makes the reflected light beam very narrow. If you increase the roughness, the light will be spread in a wider beam. This will, of course, also make the reflection of Suzanne somewhat blurry. In the image I've included, I have it set to .1, but I also tried .01 (10 times the .001 you have), and that made the interior of the cube visibly brighter.


What you've been told is correct. You'll need to adjust this number:

Then you'll need to stitch the two clips together in a video editor.

A better approach to rendering animations is rendering an image sequence of PNG's (or EXR's for full dynamic range) and then using the sequence editor to convert that image sequence into a video. Have a look at this tutorial on how to do that.


New 2.9 Feature: Correct Face Attribute (checkbox) not available in Options Drop-down

No add-on required - It's under the "Active Tool and Workspace Settings" tab:

Bear in mind, you need to be in edit mode for these options to appear - they are not present from object mode (see below). However applying these settings to one object (in edit mode), applies it to all objects in the scene.


This is not an answer but just an idea.
I'm a newbie in blender, but in cinema 4d i put a collider into the instanced object, so the instanced object it's pushed away from the object near it.


How ought I lock particles' rotation so that they always face their velocity vector?

This can be done using the Animation Nodes addon. I've made a node graph that makes particles orient to their velocity. It's kind of a hack, but basically the idea is to create an instance of the ship for every particle in the scene, and then rotate the instance according to the particle's velocity. So essentially, you're replacing Blender's particles with your own. Also, you should make the original particles invisible by going to Particle System tab -> Render and selecting "None".

Here's the node graph:

And here's a proof of concept using this node graph:


The problem I see with using an SVG file, that the once it gets converted to a mesh the topology is going to be a mess, mostly long triangles that are not going to deform or subdivide well.

It might be easier to use an image to do the displacement on a sphere (and use it also to create the texture).


Select objects in scene by their object color

Based on your comment, I guess you want to compare against the viewport display color property:

I think one easy way to compare color values is appending the components to a new list and compare the resulting lists using the == operator.

>>> [c for c in C.object.color]
>>> [1.0, 1.0, 1.0, 1.0]
>>>
>>> [c for c in C.object.color] == [1.0, 1.0, 1.0, 1.0]
>>> True

If you don't like lists for any reason, you can also convert the color to a tuple using the slice operator [:], which is even shorter -> thanks to @batFINGER:

>>> C.object.color[:] == (1.0, 1.0, 1.0, 1.0)
True

Full script iterating through Scene.objects, comparing the color values (r,g,b,a) of each object against the values of Context.object and selecting the matches:

import bpy

ctx = bpy.context
obj = ctx.object

# Object color as list
obj_clr = [c for c in obj.color]

for o in ctx.scene.objects:
    if o != obj and o.type not in ('LIGHT', 'CAMERA', 'EMPTY'):
        # Compare both lists
        if [c for c in o.color] == obj_clr:
            o.select_set(True)

obj.select_set(False)

Be aware that there are might be issues with floating point precision when comparing the values. One way around that is using isclose(a, b, *, rel_tol=1e-09, abs_tol=0.0) provided by the math module, which can be wrapped into a little helper function to test all 4 floats at once:

def compare_color(a, b, t=0.001):
    from math import isclose
    comp = {isclose(i, j, abs_tol=t) for i, j in zip(list(a),list(b))}
    return True if (len(comp) == 1 and next(iter(comp)) == True) else False

Another example comparing against Material.diffuse_color using the helper function:

import bpy

def compare_color(a, b, t=0.001):
    from math import isclose
    comp = {isclose(i, j, abs_tol=t) for i, j in zip(list(a),list(b))}
    return True if (len(comp) == 1 and next(iter(comp)) == True) else False

ctx = bpy.context
obj = ctx.object

# Object color as list
obj_clr = obj.active_material.diffuse_color

for o in ctx.scene.objects:
    if o != obj and o.type not in ('LIGHT', 'CAMERA', 'EMPTY'):
        # Compare both lists
        if compare_color(obj_clr, o.active_material.diffuse_color):
            o.select_set(True)

Further Reading: Select an object by name in 2.8 and Set active object in 2.8


Switched from cycles to blender, made render turn black and white

Not an answer to your question directly but a possible work-around:
To get a similar look to halo particles still using Cycles Render I often use a material node setup like this. So for a particle system with a kind of basic halo as the particles just create a sphere with this as the material and select object as the particle type under the 'Render' tab and use the sphere you created as the object.
Take note of the 'Blend' value in the 'Layer Weight' node. It was increased from the default 0.5 to about 0.9 to get a softer edge. Tweaking this value, the curve and the emission value should get something to your liking.


Is it possible to create seamless repeating noise in 3D

I was thinking about perhaps a 4d sphere and looked to https://en.wikipedia.org/wiki/N-sphere but this didn't produce satisfactory results due to considerable distortion at the poles.
However, on playing around with the nodes I came up with this setup :

Each of the X,Y,Z channels is passed through a Cosine function to make it cyclic and then to an Arc-cosine to make it linear again. The product of the Sine of each of the coordinates gives some travel through the 4th dimension of the noise which allow the noise to loop back to its start point without being a pure reflection of the noise - ie, straight 'bouncing' at the transition. This isn't perfect (there's some rotational symetry in the result) but is pretty close - and might be close enough for your needs.

Another option requires the use of a 6-dimensional noise texture - by generating cyclic coordinates from each of the X,Y,Z channels to produce X1,X2,Y1,Y2,Z1,Z2 (as suggested by @RobinBetts). In Is it possible to have a procedural texture radiate from the CENTER of a sphere? I did something similar using a Musgrave5D texture generated by combining two noise textures and a similar technique can be used here - but this time we have 4D noise available to us so we could theoretically generate a 7-dimensional musgrave-like texture (but we only need 6).
Consider the following nodes :

Here we're combining the output from two 4D noise textures to produce something that resembles a musgrave texture. Musgrave is very like Noise except that it has a different range of values (typically -1 to +1 instead of 0.25 to 0.75 that is typical of noise); the differing range isn't a problem since we can adjust for that using simple maths functions. The 6 inputs to the two Vector sockets can be considered as the 6 input dimensions of the noise while the two W inputs can be used as a 'seed' (you should ensure they are never set to the same value or the output will fall off to zero as they cancel each other out).
By using Sine and Cosine functions we can now take the original X,Y,Z coordinates and generate 3 sets of cyclic coordinates for input into the 6D musgrave.
Here's the complete node group :

The input coordinates are separated into X,Y,Z channels and Sine and Cosine used to generate pairs of cyclic coordinates. The result is Multiplied by a value to provide a means of scaling the noise and each set combined to feed into the associated Noise texture (note that I've opted to pass all of the cosines into one texture and all of the sines into the other - for neatness). Since I didn't need to use the W inputs separately, I've just calculated them as an opposing offset driven by a Value input node (so 0.770 results in 0.770 passed into one texture and -0.770 into the other). The outputs of the Texture nodes are combined and the Absolute allows the negative values to be seen.
This produces the following result :

Note how the noise is seamlessly repeated in each dimension. In this case the scaling of the first mapping node changes the Generated coordinates into the range 0.0 - 10.0. Since the 'cyclic nature of the Sine/Cosine functions is 2Pi (approx 6.3) this results in the pattern repeating about 2/3 of the way across the faces.
Note that if you want something closer to the output of 'Noise' (rather than 'Musgrave') you could add an Add Multiply node or a Map Range node to adjust the range as appropriate.


Cycles texture mapping, generated coordinates with world orientation?

Yes, this is possible.
There are several ways to achieve this, here are a couple:
Position:
You can use the Position output of the Geometry node and separate out the blue (vertical) channel:

Note that since it's based on the world center some objects end up with values outside the 0-1 range:

Texture Coordinate:
You can also use the Object or the Generated output of the Texture coordinate node and convert it to world space with the Vector Transform node:

Now each object will have a gradient from 1 at the top to 0 at the bottom regardless of rotation:


The select options are still available at the top of the 3d viewport, while the old version you had shows text buttons, these have now been replaced with icons.

You can find the options for the current tool in three places, in the 3D viewport header, the tool tab of the properties region and the active tool settings tab in the properties editor.

Note that we have four select tools, Select, Select Box, Select Circle and Select Lasso. The select tool has no options to show and the circle tool has less options. If you can't find the select tool options, it may be because you have the wrong select tool.