Try to use Command Prompt as an administrator  to ensurepip?

You may need to change your directory by cd "the/folder/blender/python"

It seems like the system block out the process during I/O writing to the Blender installed folder.

And be careful, Blender uses its own Python in the installed folder as the default executable Python. You may want to bind that python for installing thing through pip install.


Setting particle system to emit inside an object

Just set the source of emission to „Volume“ instead of „Face/Verts“ in the particle settings:

Result:


Can you use 1 python script for multiple GE scenes?

Yes, you can.

This has nothing to do with messages, or delays. Python is executed by a Python controller. A Python controller gets executed (as each other controller) either once or never within a single logic frame.

Messages

Messages will be transferred after the logic bricks are executed but before the next frame starts. From perspective of logic - between the frames.

That is the reason why it takes exactly one frame between sending and receiving a message.

Effect:

When you perform operations while sending a message and operations when receiving this message ... you will notify a one frame delay.
If you do not want that, you should ensure all operations (except sending the message) react on the same event -> e.g receiving the message.

  ... how would I identify an object from a separate scene?

You can grab the scene and read the objects it has.


Is it possible to simplify this mesh? I have too many vertices

If you wish to keep the overall topology of the hood, you cannot. However if you do want less vertices, there are two ways to go about doing this. The first being to lower the subdivison surface modifier. Of course this only works if you used a sud surf modifier in the first place and haven't applied it. The second way is to delete loop cuts. To begin go into edit mode and select the loop(s) you wish to remove by pressing ALT + RightClick. Press SHIFT + ALT + RightClick to select more than one.  Once selected press x to open the remove tab, finally press G to remove the loop cut.


Rotate posed character around the Z axis without deformation

The problem is that you have moved the center of the mesh and the rig several times (while in edit and pose mode). This is a big no no and would have brought about even more problems if you had continued on to do more complex transforms/animation etc.

TL;DR: Clear all your object's transforms, and update the origin points for the rig and the model.

To fix.

Select the character and the rig and hit ShiftH to hide the rest of the scene so as to work without any distractions.
Select the character HaighMan and clear all transforms, Rotation AltR, Location AltG and Scale AltS.
Select the entire rig, which is currently in pose mode with A and repeat the previous steps for clearing all transforms.
Still selecting the rig, use CtrlTab to go to object mode and repeat the steps again for clearing transforms.

Providing you followed the steps above, your scene should now look something like this.

Select the rig and Tab into edit mode and adjust it to fit the model, select the root bone and use ShiftS > Cursor to Selected and then use CtrlShiftAltC > Origin to 3D Cursor. You can then select the rig in object mode and rotate the character 90° on the Y axis to have it stand upright.

All should be well now, it is fixed but still broken as your previous animation keyframes are still on the armature. I would highly recommend clearing these and animating it again and also re-applying the model to the armature. If you now hit play, it will jump to the keyframed location and the character will start walking, you are now also able to rotate and scale each bone without any weird deformations.

More reading:

Weird Armature Deformation
How do I apply a simple armature that I made to a model?
How can I automatically generate vertex groups for an armature?


How can I use blender's python API from a Ipython terminal or Jupyter Notebook?

One of the most important things to be aware of is installing the correct version of the tools:
Using the current 2.91 Blender version we should use Python 3.7. We can install that using Anaconda3 2020.02 from exe, list of packages.
After that we need to install the blender kernel from here, using the following command in anaconda terminal:
python -m pip install blender_notebook
blender_notebook install --blender-exec="C:\Program Files\Blender Foundation\Blender 2.91\blender.exe"

Now, when we start Jupyter Notebook we can select blender kernel.
First, you need to import the Blender specific library bpy:
# blender related imports
import bpy

After that, we are able to use many examples, already available out there.
I've made an example Jupyter Notebook on this topic, available here
See the discussion and plans on updating blender's python version here.


Add vertex without subdividing edge then vertex slide?

First off you can use the knife tool to add only one vertex.
All you have to do is LMB  on one side of the edge, then LMB  on the other side, and press Enter or space to confirm.

There is another, potently faster, way of creating a new vertex. That is done by selecting a vertex on the end of the edge you want to subdivided and pressing AltD then G. That will run the Rip Edge tool then edge slide to move the vertex to where you want it to be. Because that tool automatically starts the translation on the new vertex you only have to press G once to get to vertex slide mode.

However using any of these methods will create Ngons, and in most cases really mess up your topology. So you should be very careful how and when you just add a new vertex in the middle of your mesh.


How can I create a point cloud from the surfaces of a model?

Following script creates a new point cloud from the selected object based the center of each face:

import bpy

def point_cloud(ob_name, coords):
    """Create point cloud object based on given coordinates and name."""
    me = bpy.data.meshes.new(ob_name + "Mesh")
    ob = bpy.data.objects.new(ob_name, me)
    me.from_pydata(coords, [], [])
    ob.show_name = True
    me.update()
    return ob

def face_centers(obj):
    """Returns median center coordinates for each face of given mesh object."""
    if obj.type == 'MESH':
        import bmesh
        bm = bmesh.new()
        bm.from_mesh(obj.data)
        return [obj.matrix_world @ f.calc_center_median() for f in bm.faces]
    else:
        return [(0.0, 0.0, 0.0)]

ob = bpy.context.active_object
pc = point_cloud(ob.name + "-pointcloud", face_centers(ob))

# Link object to the active collection
bpy.context.collection.objects.link(pc)

Related: Add a simple vertex via python?


Drive Objects Rotation depending on state of other objects sin and cos value

This can be done two ways :
scripted expression : which should be one line of code and it may get complicated
driver function : this will make it a lot easier to control and create complex driver, we define a function then use it in the scripted expression

scripted expression :

floor(b/(2*pi))*pi/2 + (cos(b)>0 and sin(b)<0)*(b-1.5*pi) + (b< 0)*2*pi

where b is the angle  of the red cube

driver function:

we define a new function calc_angle() and add it to the driver namespace, this function calculates the angle the same as the scripted expression but its easier to read, update and reuse in multiple drivers .
run the script in blender's text editor

import bpy
from math import *

two_pi = 2*pi
pi_two = pi/2

#create new function
def calc_angle(angle):

        new_angle = floor(angle/two_pi)*pi_two

        if cos(angle) > 0 and sin(angle) < 0 :
            if angle > 0 :
                new_angle += angle-1.5*pi
            else :
                new_angle += two_pi + angle-1.5*pi
        return new_angle

#add the function to the driver namespace
bpy.app.driver_namespace['calc_angle'] = calc_angle

and setup the driver as follows :


How to align (rotate) mesh by 2 verticles?

TeeTrinker is right: have you tried using the 3D cursor as the "Transform Pivot Point"? Snapping to other geometry does not work in this mode, so if you need absolute precision, I would recommend an add-on like Mesh Align Plus. It has many alignment options, but the one you are looking for in it is "Quick Align Lines". Keep in mind there are far more advanced options that may save you time later on.

Using Mesh Align Plus add-on, here's what I did to achieve the rotation you described:

Create a new plane mesh object with a side aligned to the final upright green line orientation you showed in your image.
Select this new plane, entered Edit Mode, select the edge
representing the green line, Mesh Align Plus>Quick Align Lines>Grab
Destination. Exit Edit Mode.
Select your plane you want to rotate.
Enter Edit mode. Select vertex 1 and vertex 2 like you show in your picture. Exit Edit Mode. Mesh
Align Plus>Quick Align Lines>Apply to: "Object".


Create new object from selected faces while retaining faces on old object

Check this .GIF:

Select faces
Shift-D then right click to duplicate
Press P to separate


Holes in my final render that don't show in my preview

I can bet, you use different subdiv levels for your preview, and render. If you make it equal, you will see the trouble in the viewport too.


For a floating panel that stays in place you might want to read this question.

For something closer to the operator properties panel you could define a custom draw method to send to custom popup menu.

def draw_popup(self, context):
    col = self.layout.column()
    row = col.row()
    row.label("Hello World")
    row = col.row()
    row.prop(context.scene.render, 'resolution_x')

class ShowPopupOperator(bpy.types.Operator):
    bl_idname = "object.show_popup"
    bl_label = "sample show popup"

    def invoke(self, context, event):
        context.window_manager.popup_menu(draw_popup, title='Test this', icon='INFO')
        return {'FINISHED'}

To show the operator properties as shown in your question you can use the invoke_props_popup. To customise the display you give your operator a draw method.

class ShowPopupOperator(bpy.types.Operator):
    bl_idname = "object.show_popup"
    bl_label = "sample show popup"
    bl_options = {'REGISTER','UNDO'}

    prop1 = bpy.props.IntProperty()
    prop2 = bpy.props.FloatProperty()

    def invoke(self, context, event):
        return context.window_manager.invoke_props_popup(self, event)

    def execute(self, context):
        # do stuff here
        return {'FINISHED'}

    def draw(self, context):
        col = self.layout.column()
        row = col.row()
        row.label("Hello this the operator drawing")
        row = col.row()
        row.prop(self, 'prop1')
        row = col.row()
        row.prop(self, 'prop2')


Hi eiipaw well the way to simplify why dynotopo is the way it's is all about the quality of the detail plus their is a limitation for what your current geometry can and cant do.

So without dynotopo you are just using the current geometry of your mesh and moving it around to create detail, this can cause serious artifacts and distortion if you plan on baking normals, Dynotopo for the contrary it adds small polygons by extraction or addition, so it adds more topology to your mesh instead of only moving it around.

That detail was done by dynameshing the anvil, I would have never being able to create that sharp detail without dynameshing, So i would said rule of thumb if your model is not that detail, and only moving around the geometry gets you the detail that you want; go for regular sculpting is easy and less taxing to your computer, but if you are doing like ultra detail crevices or damage with some grunge. Or a character with a lot of detail like a porous skin, go for dynamesh. You can also simulate detail by painting directly on a model. That's what blizzard does, although they use sculpting to bake on normals for specific things. Just look at blizzard atist portfolios sometimes they show you the maps that they used.

Finally remember that if you use sculpting detail on a mesh, think what is the purpose of your model, if your model is for games or animation you want to bake the normals (you dont want to have millions of polis on an engine or huge render times to render a scene). For the pixel size think about how close is that object or character in realation to the camera. And experiment experiment, Experiment!


Bone Layers in Edit Mode are Different Than in Pose Mode

It looks like your bones have custom shapes, if you go in Pose mode, select a bone, go in the Properties panel > Bone > Display > Custom Shape, some meshes are used to display the bone in another way than a classic octahedral shape. Press on the little X to delete. I don't think you can delete them all at the same time.


Where are the modifier scripts in the Blender package contents folder?

Blender's modifiers and physics related routines are written in C/C++, you won't find them in the scripts directory. Download Blender's source here as an archive or use GIT


I separated arms from the torso of a model, how can I seamlessly attach them again?

You could just snap vertex and then merge them by distance (or remove double vertices)


You definitely need to have a higher resolution mesh to sculpt. If you have not applied the skin modifier yet, you need to do so. You should save a copy of your .blend file before this. Then you need to subdivide your main mesh, as the skin modifier is a very very low quality mesh creator, when not subdivided. After all that, you should be able to sculpt the mesh. If you still cannot, then please post an image so I can see what settings you have for the mesh. A .blend file would also be helpful.
If this does not answer the question, please say so in the comments below.


Sounds like you have to use drivers, as far as I know a Modifier belongs only to one object so it cant affect other objects as you imagine.
In your case I would create a controller object (an empty for instance) or just a property in my main object so I can control the rest.


After import to Unity, back faces are transparent

There are a few different things that might be causing your problem.

Firstly, there's no way to add thickness without increasing the tri/poly count. Polygons only have one face, so if you view them from the "wrong" side, they are invisible. There is no way to avoid this. If you want to see both sides, you have to have another polygon that is facing the other direction.

The first step is to make sure that when you add thickness in Blender, that you're adding REAL thickness, instead of using a modifier. If you do use a modifier, you need to "apply" before you export to Unity (there's a way to apply on when you export, but I won't talk about that right now). Either way, they have to be "real" polygons that get exported, not just the result of a modifier.

The next step is to make sure that all of the normals of your polygons are facing the right way (outward). If you select all of your polys in Blender and press ctrln then it should recalculate all of your normals "outside."

Once you've done these two things, try exporting to Unity again, and see if that helps.


The bevel weight is visualized in light blue (similiar to the teal sharp).

You can edit the weight in Edit Mode by selecting edges and pressing ⎈ CtrlE to open up the edge menu (which can also be accessed through the 3d View's header menu bar).
In the edge menu choose Edit Bevel Weight. The bevel weight can also be accessed in the Properties Panel N of the 3D View. The bevel modifier can use the bevel weight to restrict the beveling.


Is there a way to repeat a set of actions on an object?

One way is the repeat history F3. You can select the other object and redo the steps in the list one at a time. It's a bit tricky since the actions aren't numbered and repeating one changes the order.

What you could do is open a text editor, create a new textblock and type

import bpy

Then pull the info editor on top of the screen down. The lonely header up there is actually a full window/editor. In ancient times, the preferences were hidden in it. There are all the actions you performed in python form.

Just do what you wanted to do once with any object.

Then right click the commands you want to use in the info editor. They should turn blue. CTRLCCTRLV them into the text editor below the import statement.

Now you can perform the copied list of actions, provided they're compatible, with any selected object simply by pressing ALTP in the script window or using 'Run Script'.

There might be an addon for macros, but this is one way of creating your own.


Does this flat 5 sided face count as a square?

It is a pentagon or the more common general term in 3d, a n-gon. You probably want to avoid these for anything realtime such as games or animations since they do not deform or smooth well, make adding more detail cumbersome and games are more optimal with triangulated meshes.

As a simple flat object, it's fine if you are done with the model but again as a rule of thumb, try to stick with quads and tris.

To resolve, you can either:

Use the join tool (select both vertices and press J).
Use the knife tool (K, select a star point and drag to cut, use Enter to confirm) to create a tri from the extra vertex or create quads by continuing the edge flow downwards.


Select the face you want holes on
Inset all faces by pressing "i"
Extrude all faces by pressing "e"
Extrude all faces by pressing "e", press "g" and drag them down
Extrude all faces by pressing "e"

(3. and 5. sharpen the edges, so you don't have to add Loopcuts/Edge Creases)


How to stretch selected vertices to mathfunction or bezier

What you want can be done in a number of manners, but most of them are retopology tools:

RetopoMT by Blenderlounge:

https://youtu.be/op2rMKDEUzQ?t=566

SpeedRetopo by Cedric Lepiller

https://youtu.be/BFfqePn8nKI?t=21

https://youtu.be/NdbBX957JYo?t=286

Retopoflow by cgcookie:

https://www.youtube.com/watch?v=9qidVmJjtBA

Bsurfaces:

https://youtu.be/3VC98kiy10Q?t=117

https://www.youtube.com/watch?v=mptQWDbKhW0

Mira Tools for editing loops as curves:

https://www.youtube.com/watch?v=iO4OjsqJpxQ

Curve Tools for nurbs modeling:

https://blenderartists.org/forum/showthread.php?221213-Tools-for-curves

Also, on the same LoopTools addon that you use, there are options on the W menu for relaxing and spacing of the vertices, they may be useful in your case.


Render specific frames with opengl via python

You have to call Scene.frame_set() instead of setting the property Scene.frame_current:

bpy.context.scene.frame_set(234)

Only frame_set() updates animation data correctly. frame_current is mostly intended for reading access to determine the current frame.

Following example renders frame 0, 230, 99 and writes them to the disk as test_000.png, test_099.png and test_230.png.

import bpy
import os

# format integer with leading zeros
def formatNumbers(number, length):
    return '_%0*d' % (length, number)

# get the scene
scn = bpy.context.scene

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

# set filename
filename = "test"

# set render frames
render_frames = [0, 230, 99]

# iterate through render frames
for f in render_frames:
    # set the frame
    scn.frame_set(f)
    # set filepath
    scn.render.filepath = os.path.join(
            output_path,
            filename + formatNumbers(f, 3) + ".jpg",
            )
    # render opengl
    bpy.ops.render.opengl(write_still=True)

# reset internal filepath
bpy.context.scene.render.filepath = output_path

Note: .jpg is only a placeholder and will be overwritten by the settings in the render panel.


Here is my solution (Some description): I have 4 horizontal bones(small red one IK_Target), they all have a 'Limit Distance' constraint to each other. Moving IK_TRGT causes the bones to come out one at a time - that gets the action you require. The rest is just 2 sets of bones parented to each other(yellow to purple), yellow bones have IK targeting the purple bone in front of it which is parented to its corresponding larger horizontal bone. I have them all stacked on top each other when built, that can be fixed last to get some offset.Forgot to mention if this rig is going to traverse the Scene it will need a ParentBone to avoid unwanted transforms.

DISCLAIMER: This file created in v2.76 - If using 2.7x it will open fine,, If using 2.8x 'APPEND' the objects from the 'Object' folder.


How to use subdivision modifier properly on this cylinder?

I agree with lemon's previous post. Although using a cylinder for a wing seems to make sense, it's just not a good way of creating mesh. Better to either start with a cube and subdivide it as more detail is needed, or learn how to keep good quads/edge loops and just altogether good practices for mesh creation.


Trying to add physics to leather strap on thors hammer

I can't explain how to get the soft-body physics to work, because I myself still don't entire understand soft-body physics.

However, I can give an alternate way that I know works.

-Instead of using a curve, create a mesh that is just a single edge-loop, no thickness.

-Add cloth physics to it.

-Select the vertices of the area that is inside the hammer handle (going a couple vertices outside the volume of the handle mesh will help avoid collision glitches as well as add to the stiff look), and add them to a vertex group.

-Under the cloth physics, toggle on "Pinning", and select the vertex group you just made.

-In the modifiers tab, you'll see a cloth physics modifier.  After this modifier (that is, below it), add a solidify modifier; increase the thickness as appropriate.

-Add collision physics to the hammer mesh.

-Parent the strap mesh to the hammer mesh.

-I found that cranking up the "Bending" parameter under the cloth physics goes a long way in emulating the stiff, cord-like physics of the real strap in the movies.


Blender 2.8 Cycles Importing Image as Plane isn't transparent

@rjg got it right.  Turns out the transparency pattern in the back was inside the image itself - might be because of Google Images.

Everything is working smoothly now!


I found what I was looking for. The button I needed was "adjust edit cage." It bought down my "edit cage (which I couldn't figure the name of, making this question more confusing)" down to the jumpsuit mesh. See pic below for the button I used.


so, I watched the video but couldn't see the moment where he showed the origin of the hooks.

However, I think you should look into the "Set Origin"-options. You can open them by pressing "Space" and typing "Set Origin" into the appearing text box. Or just use the short cut "Shift + Alt + Ctrl + C".

Select all the hooks and choose one of the options. Try out whether one of them results in the wished origin position.

Greets
Jaspa

--- EDIT ------------------

Ohh god, I fixed it xD
You always tried to give the empty elements the origin. But first: empty elements have no origin, just a location (see my link in the comments for more details). And second: That's not what was  done in the tutorial.

To achieve the same origin as in the tutorial, you need to select the armatures (the whole bird) in Object Mode. Therefore you just need to click any bone. Once selected, you need to center the 3D cursor (as described in the comments too). Now you can use "set origin" options for applying the new origin. Et voilà: You've got the same settings as in your tutorial.

Have fun :)


Recreating toggle shading mode hotkeys in 2.8

I was so distracted hunting down 2.8 methods I completely overlooked the seemingly disabled dropdown that appears when you use the VIEW3D_OT_toggle_shading method:

Despite being grayed out, it's interactive. That's where you set the type, not through the code.


Animation Nodes doesn't have a node that can write vertex weights yet. So we will have to use some python to implement that ourselves. Given an object obj with a vertex group vertGroup and a float list weights containing the weights for each vertex, one can use this expression to set the vertex weights:

[obj.vertex_groups["vertGroup"].add([i], w, 'REPLACE') for i, w, in enumerate(weights)]

It is essential that the input object of the expression node be the output of the node used to set the mesh, this ensures the vertex weights to be set after the mesh is set.

Now, if you want to paint the weights by hand and have it preserved even when you are resetting the mesh each execution, you can do the following:

Disable the Mesh Object Output node temporarily.
Paint the weights.
Cache the output of the Vertex Group Input node (caching is described in the documentation here)
Enabled the Mesh Object Output node and use the cache in the node tree we described above.


Here is how I would do it

Wrap your expression inside a LaTeX document

\documentclass{standalone}
\usepackage{lmodern} %or whatever you like
\usepackage[intlimits]{amsmath}
\usepackage{amsthm, amssymb, amsfonts} %Useful stuff
\begin{document}
$ <your expression> $
\end{document}

Pipe that to pdflatex, or save it to expression.tex
If you used a pipe:

pdftocairo -svg texput.pdf expression.svg

If you used a temporary file:

pdftocairo -svg expression.pdf expression.svg

Import expression.svg into blender
Remove temporary files created by pdflatex.

This procedure can be converted into an addon. The dirty way of doing it is to modify the svg importer to run steps 1-3. The correct way is to use Python bidings for Poppler to load the pdf directly.

Test case:

\documentclass{standalone}
\usepackage{lmodern} %or whatever you like
\usepackage[intlimits]{amsmath}
\usepackage{amsthm, amssymb, amsfonts} %Useful stuff
\begin{document}
$\displaystyle\mathcal{F}\left[f\right](\xi)=\int_{-\infty}^\infty   f(x)\exp(\mathrm{i\xi x})\,\mathrm{d}x$
\end{document}

Result (after some tweeks [curve to mesh, remesh, smooth]:


Low poly mesh interrupting normal map in render

There is only so much a normal map can do, see for example this tutorial for an in depth explanation of how it works and what the limitations are. TLDW; changes to the silhouette cannot be represented in a normal map. For situations like your second example a normal map cannot give any close approximation of the original appearance. You could try vector displacement instead if you want.

That said, your first example should be doable with a normal map.

Make sure your low poly object is smooth shaded before baking.
Try adding a little geometry to sort of follow the contour of the high poly mesh (even simply beveling will help reduce terminator artifacts)


Grease Pencil primitive/shape tools do not function

After some messing about, I deleted my user preferences to find that it solved the issue.
Unsatisfied with this catch-all fix, I endeavored to find out why, and went through each setting, enabling and disabling it to see its effect.
It turns out that my keymap, being the same keymap I've been using for, perhaps years, still being retained through to 2.92, somewhat customized, caused the issue.
I do not know why, or how, but not using it seems to fix the issue entirely.
Perhaps there are some formatting issues, as clearly my old keymap file does not load the same Preferences menu that the new default ones do.
It also seems that it doesn't know what about itself has been changed, as it marks parts of the keymap as being able to be restored, when I did not change those parts. Perhaps the keymap is corrupted.
I have no idea how the keymap having problems would affect the ability of the tools to function, but apparently it does.


Having quite a bit of trouble with Baking

The hair looks to me like a problem with the normals, to recalculate normals select all the hair polygons on edit mode and click on Mesh -> Normals -> Recalculate Outside. Regarding to the colors, maybe you are changing the viewport color texture instead of using real material colors, for that when the object is selected check the materials. Also don't trust totally the render view, if your environment light is black and your hair is black your texture will end up being practically all black, try changing the light environment to white, its so easy, just clicking on the world icon and move up the color light environment slider to have white light environment. Maybe any of this helps or makes you dominate something new :-)


Apply complex hole pattern to simple face while maintaining good topology

If the pattern is tiling then maybe create a small section first.

If it were me, I would rather import the "white portions/ not the holes" svg as a plane, remesh that plane (example used is Text but SVG acts like a text object, same topology problems https://www.youtube.com/watch?v=16_Xhzg6bRQ
 and/or https://www.youtube.com/watch?v=7ZDwMzjVBi0) and then solidify it. Then apply a horizontal and vertical array. After creating a big enough plane, use your desired object as the intersect boolean of the arrayed pattern.

In general, Bools create messy topology. Some addons can help you fix those topologies. I personally use QUAD REMESHER but its a paid add-on. I heard Mesh machine can help you fix these issues too but I don't have that add-on.

Alternatively, you can try learning how to do bools while avoiding messy topology. I recommend Arrimus 3D's Master Booleans in Blender https://www.youtube.com/channel/UCSLLdTBwLMfTKWS56tOiQpw/search?query=master+booleans+in+blender

Hope this helps.


select a loop of faces
press I
press again I
scale by moving the mouse towards the center of your object
Click  LMB  (left mouse button)
press  E  do not move the mouse, I immediately
press  S  and now scale to the desired size
Click  LMB  (left mouse button) to end the action

NOTE

 I  (inset) x 1, with only one face selected, it will
create a single frame on that face
 I  (inset) x 1, with a loop of Selected faces will create a single frame on that face within the range of selected faces
 I  (inset) x 2, with a single face selected will create a single frame within each face of the selected range


You should deselect non mesh objects before adding rigid body objects

 bpy.ops.object.select_all(action='DESELECT') #clear selection
 candidate_list = [item.name for item in bpy.data.objects if item.type == "MESH"]
for object_name in candidate_list:
    bpy.data.objects[object_name].select = True

this also should be done when clearing the scene if you want to keep the camera and light sources. and regarding the context see this answer poll() failed, context incorrect?


How can I know where the normal ring is convex and where is concave?

This is a Tangent Space normal map.
That is to say, blue (Z) represents the interpolated normal of the underlying geometry, red (X) represents a tilt towards the tangent direction, which is positive X in the UV, (texture,) space, as mapped onto the surface, and green represents a tilt towards the bitangent direction, which is positive Y in the UV space, again, as mapped onto the surface of the geometry.
To quote directly from the Wikipedia page on normal mapping - 'How it Works':

A normal pointing directly towards the viewer (0,0,-1) is mapped to
(128,128,255). Hence the parts of object directly facing the viewer
are light blue. The most common color in a normal map.
A normal pointing to top right corner of the texture (1,1,0) is mapped to
(255,255,128). Hence the top-right corner of an object is usually
light yellow. The brightest part of a color map.
A normal pointing to
right of the texture (1,0,0) is mapped to (255,128,128). Hence the
right edge of an object is usually light red.
A normal pointing to top
of the texture (0,1,0) is mapped to (128,255,128). Hence the top edge
of an object is usually light green.
A normal pointing to left of the
texture (-1,0,0) is mapped to (0,128,128). Hence the left edge of an
object is usually dark cyan.
A normal pointing to bottom of the
texture (0,-1,0) is mapped to (128,0,128). Hence the bottom edge of an
object is usually dark magenta.
A normal pointing to bottom left
corner of the texture (-1,-1,0) is mapped to (0,0,128). Hence the
bottom-left corner of an object is usually dark blue. The darkest part
of a color map.

By Julian Herzog, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=25512888
From this, you can see the top disc is convex, and the bottom disc concave.


You can use Deactivation for this instead. Make the rigid body objects that you want to enable sequentially Active with Deactivation and Start deactivated enabled:

The rigid bodies will then start stationary, and only activate if another rigid body comes close to them. Even an animated rigid body can activate them:


How can I animate multiple objects to be highlighted in a scene?

You could duplicate all the objects (perhaps scale them up a percent, and maybe put them all in a separate collection), and give the all duplicates the same material with Make Links (Ctrl + L) > Material. Then do something like make this material have a Mix Shader, with a Transparent BSDF and red Diffuse BSDF plugged into it. Then Animate the Fac value of the Mix Shader.

EDIT:
You could do the work but copy-paste the extra nodes and copy-paste a driver in the Mix Shader to decrease the amount of manual work.
Add an empty, add a custom property (Object Properties > Custom Properties), give it a nice name (optional), right click the value field and choose Copy Data Path.

Create a node setup with a Mix Shader as an alternative output for a material. Give it a nice frame (optional). Right click the Fac value and choose Add Driver.

Edit the driver right away when it pop up, or with the Mix Shader selected go to the Drivers window. Type: Scripted Expression, Expression: "var", for Prop target the empty object, and hoover over Path: with the mouse and press Ctrl+V to paste the custom property data path.

Sadly when you copy-paste the highlight nodes to another material the driver  isn't copied with it, but you can easily copy paste a driver by right clicking the field where the driver is applied. Connect it to the other nodes, and no need to delete anything; the last selected Material Output becomes the active one. (Once i had the nodes and driver set up, it took me only a few seconds to paste an connect them in to each material.)

Since all drivers share the data path they are all driven by the same custom property. And it can be animated.


Fastest way to export files multiple passes into folders?

The File Output Node is exactly what you are looking for.
Unfortunately the documentation does not mention how to get it to output to different subfolders, but thanks to sambler you can have each file go into its own folder.

The settings for the File output node  are in the properties region, press N to open it. Such things as file format, compression, the input's name and adding inputs are all only accessible there.
To add outputs to the file output node click on the large "Add Input" button.

Now you will have to add a slash (forward or back slash, does not matter on windows) at the end of the name of the input, like in the image below. For example, to have all your AO passes go in am AO folder you would name the input "AO\", or "AO/" (I use the backslash for consistency in windows file paths).

Or you could use a separate file output node for each folder you want to create. I have not noticed any difference in performance.

During the compositing stage blender will automatically save all the files specified in the file output nodes.


Smoke domain position problem in solid mode but not in render mode Blender 2.92

You probably moved the emitter and yet still have an old cache in your smoke Domain;

Go to the Domain and in Cache: change the Type to something else and then back again to clear it.   Or go to the folder with the cache and delete all sub-folders/files.    Unlike other types of "baked cache" (cloth, particles) there is no Delete back or Clear Cache feature for Fluids, sadly.


blender internal clouds

all default settings, shadeless material.

cycles noise

Niose texture Scale set to 8. All rest left to defaults. Cycles shadeless material, with a RGB Curves node to boost the contrast in the Noise Texture.

With those few settings changed you can get the cycles noise texture look very much like the blender internal clouds texture.


What are these spheres at bottom-right in 3d viewport?

The spheres are called HDRI Preview spheres, in older Blender versions known as Look Dev HDRI spheres. You can turn them on/off in the overlay menu. It is used to check the lighting setup of an HDRI.


Is there a way to add a new element to a mesh in the action editor?

You can add an intermediate bone, which deforms the medal. On the first frame of the winning animation it will simply have a scale keyframe at (1, 1, 1). On all other actions you keyframe it to a scale of (0, 0, 0) effectively hiding it.

Otherwise create a separate object, which the game engine can show/hide.


how to change boolean cutter to wireframe automatically?

You need to check the 'use wire instead of Bbox' in addon preferences.

Ctrl + Alt + U  to bring up this 'user preferences' window (just in case)


Particle edit - Comb, smooth, etc...

The greatest difference I can tell is probably caused by the lack of editing of the hair particles. They are currently pointing outard the faces normal (the default behaviour) like small spikes.

As you already noticed, the fur look quite short, but in my opinion reducing the lenght can't alone do the job. You'll need to bend it toward the skin by to combing the fur, in the right direction. Take for example the pokemon's forehead fur where you can clearly see that hairs are pointing upward.

Don't forget to add some variance to the children (e.g. with curl, wave, spiral... kink setting). In the following image you can see the same fur ball combed and with a Curl Kink of 0.002.


Some parts of my project aren't saved in the .blend file

Blender does not save unused datablocks you need to add a fake user to store datablocks that are not in use. See DataSystem Sections Users and Fake User

The setting of mip-maps is not stored in a .blend file you would need to save the user-preferences in the same dialog (button in the lower left corner).

Related:

What does "users" means in term of datablocks?


Apparently the solution to this all along was restarting my PC, which I didn't think would fix the problem so I didn't try in the first place.


Found solution:
Edit mode: Delete Cylinder
Switch to object mode: Add Cylinder
object mode: Scale Cylinder up
Switch to Edit mode: bevel


What algorithm is used for "beauty" triangulation

After a quick look at the source code, I believe it tries to find a triangulation that leads to the best angles for each triangle (ie biggest minimum angle and smallest maximum angle).
For a quad, there are only two possible splits so it tries both.
For a polygon with more sides, it does some sort of greedy iterative search of an initial triangulation and edge rotations.
Possibilities where triangles that are flipped relative to the initial polygon are discarded.
Relevant code:

bmo_triangulate_exec in https://github.com/blender/blender/blob/master/source/blender/bmesh/operators/bmo_triangulate.c
BM_mesh_triangulate in
https://github.com/blender/blender/blob/master/source/blender/bmesh/tools/bmesh_triangulate.c
BM_face_triangulate in
https://github.com/blender/blender/blob/master/source/blender/bmesh/intern/bmesh_polygon.c
BM_verts_calc_rotate_beauty in
https://github.com/blender/blender/blob/master/source/blender/bmesh/tools/bmesh_beautify.c
BLI_polyfill_beautify in
https://github.com/blender/blender/blob/master/source/blender/blenlib/intern/polyfill_2d_beautify.c


Python: Assign selected faces to vertex group

You have missing "bpy" on line 4, so it should be:
group = bpy.context.object.vertex_groups.new()

Don't forget to import bpy:
import bpy

Whole script:
import bpy
sub2 = 0
bpy.ops.mesh.select_all(action='SELECT')
bpy.ops.mesh.select_random(percent=55, seed=10, action='DESELECT')
bpy.ops.mesh.split()
group = bpy.context.object.vertex_groups.new()
group.name = ("Island" + str(sub2))
#group.add(bpy.data.objects.data.verts, 1.0, 'ADD')
bpy.ops.object.vertex_group_assign()


Working on a slice & mirror modifier combo script (a la 3ds max). Unable to stack modifiers. [Beginner]

When you add the second boolean modifier, it is automatically named as Boolean.001, but then you change the properties of the first one you added, named "Boolean", by using bpy.context.object.modifiers["Boolean"].

Instead, add the modifiers like this:

    boolean_modifier = mirobj.modifiers.new('Boolean', 'BOOLEAN')

The first parameters is the name of the new modifier, the second is the type: bpy.types.ObjectModifiers

And then change the properties like this:

    boolean_modifier.operation = 'DIFFERENCE'
    boolean_modifier.solver = 'CARVE'
    etc...

This way, even if it's automatically renamed to Boolean.001, you will be editing the properties of the modifier you just added.
Same for the mirror modifier.


how to hide mesh but keep hair particles

PropertiesEditor-->Particles-->Render-->Emitter.

this will hide the mesh in render view


Python system version vs python Blender internal version

Blender comes bundled with it's own Python. It doesn't have anything to do with your system Python and you shouldn't try to mix the two, this will only give you headaches. Stay with whatever Python version Blender provides for your Blender scripting.

If you need additional libraries for Blender's python, you can install them in Blender's Python directory (in the directory you installed Blender in, navigate to blenderversion/python/lib to find the standard python library path), or install the libaries somewhere else and adjust sys.path in your python scripts before you import them.

There are reasons why Blender does not use the System Python installation. The first one is that no Python might be installed, but much more importantly, Blender's python API is developed against a specific Python version - the one bundled with Blender - and Blender can't guarantee that it will work with any other version of Python. If you try to trick Blender into using your System Python, you might encounter strange bugs nobody else has seen. This way lies madness.

Note that even pure Python projects often use virtual environments to isolate themselves from the System Python installation and provide a known environment.


I would make this with linked duplications that I would join later on, but you could do it with 2 Mirror modifiers:

Create your shape. Put an empty on the axis.
Give your shape a Mirror modifier, choose the empty as Mirror Object.
Rotate the empty 45° on the Z axis.
Create a second empty (perhaps another shape) at the exact same place as the first one.
Give your shape a second Mirror modifier, choose the second empty as Mirror Object.
Rotate the second empty 45° on the Y axis.
You should be right.


Apply shader color based on distance to mesh surface (Sculpted Mesh)

This is rather easy to do with an object that has a MultiResolution modifier as you mentioned. Such a mesh offers the possibility to bake the displacement from the base mesh to the subdivided one into a 32bit displacement map, and re-use that input for color ramps to drive the material color. Such a workflow also allows you to clearly distinguish between indentations and elevations as a bonus.

First, create your mesh as usual, and make sure there is a proper UV map to it. This UV map is critical for baking, so the better the layout, the better the displacement quality. Sculpt your detail into the MultiResolution modifier.

Next, create a texture of a reasonable size (I chose a 2K image in this example), and make sure it uses 32bit Float. This will make sure that there is enough image depth available to avoid banding artefacts in the texture, making it perfectly smooth:

Now create a material on the object, and use the image in the node tree, connecting it with the UV map. It doesn't matter yet where you connect the texture to, but you can already pipe it into a color ramp and the result of that into the Shader:

Now make sure that the image texture node in the Shader Node Tree is the active node (white highlight frame around it):

You are now ready to bake the displacement. The mode we will use records the difference between the Preview level of the modifier and the highest sculpt level, so in general you will set the preview level to 0 before baking:

Go to the Render Properties tab in the Properties Editor, and open the Bake Panel. Set the options as follows to bake the Multires Displacement data into a map:

By now, your object should look like this:

And after re-enabling the Preview subdivision levels to the max, like this:


Cycles why image squence texture is automatically animating?

You need to animate the 'offset' value of the image node. The offest needs to decrease by one for every one frame you go forward.

So on frame 5, you would need to make the offset '-4' as you have gone forward 4 frames (from frame 1):

So even though you have gone forward it will still show frame 1 of the image sequence.

If it was frame 7 you would offset by '-6' frames to still only show frame 1:

The following only works for the viewport, not the render.

You have 'Auto Refresh' turned on on your image nodes:

Turn this off if you don't want the frames to update automatically on frame changes.


Blender 2.8 Grease Pencil - How to draw continuous lines

To draw a polygon (i.e. a set of connected lines), use the Poly function. It's right next to the Line button:


Shadeless mesh that's being affected by lighting?

What you describe is not a shadeless material.
You can try and mix an Emission shader with another non emitting shaders like Diffuse or Glossy shader, giving you a blend between shadelessness and light interaction with your scene.
Just connect a Shader Mix node input sockets to different combinations of emission/diffuse/glossy and try them yourself.
Alternatively look into an Ambient Occlusion shader node. It doesn't react to scene light, instead being self shadowed by other geometry only. If correctly setup with a low distance value it can simulate shadelessness to a certain extent while keeping proximity shadows.
One final note, if you are not looking for photo realism and instead rendering lost of NPR stylized stuff Cycles, being a physically based render engine, may not be the most indicated for you. There are other faster less resource hungry engines out there that may be better suited for your work, like Blender Internal or even simply the OpenGL viewport.


How to get Property Panel attached My Panel?

Reuse the code.

Can turn on developer extras and view the source of most of blenders UI.
An option would be to copy the code needed and add to a new Panel class.
A rub is the properties area often has context members unique to the region. For this  case  context.particle_system is defined in the properties area in particles tab.
Would instead need to be edited to context.object.particle_systems.active
Monkey patching and passing context object with extra members.
As an example have given new panel a method which refers to blenders UI class draw method.  A namespace object is used to create a context with the extra members and passed to the draw method as a proxy context object.
Similarly with  the poll method of the PARTICLE_PT_render_collection class.
Could do same for  draw_header
Have, however,  simply added the use count property to the draw method, it could however be used in a draw header method to replace "Hello World" title.
import bpy
from argparse import Namespace

from bl_ui.properties_particle import (
         PARTICLE_PT_render_collection_use_count,
         PARTICLE_PT_render_collection)

class HelloWorldPanel(bpy.types.Panel):
    """Creates a Panel in the Object properties window"""
    bl_label = "Hello World Panel"
    bl_idname = "OBJECT_PT_hello"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'UI'

    @classmethod
    def poll(cls, context):
        ps = context.object.particle_systems.active
        c = Namespace(**context.copy())
        c.particle_system = ps
        return PARTICLE_PT_render_collection.poll(c)
    # monkey
    draw_part = PARTICLE_PT_render_collection_use_count.draw

    def draw(self, context):
        layout = self.layout
        ps = context.object.particle_systems.active
        if ps:
            layout.prop(ps.settings, "use_collection_count")
            c = Namespace(**context.copy())
            c.particle_system = ps
            self.draw_part(c)

def register():
    # fake a pin_id for 3d view.
    bpy.types.SpaceView3D.pin_id = None
    bpy.utils.register_class(HelloWorldPanel)

def unregister():
    del bpy.types.SpaceView3D.pin_id
    bpy.utils.unregister_class(HelloWorldPanel)

if __name__ == "__main__":
    register()

Note, this is only a proof of concept.  Other things to consider when moving from properties area elsewhere is context.space.pin_id for when the panel is pinned.  Have added another monkey patch to set pin in 3d view to none.


When rendering an image the output is grey

Your Render Layer is not connected to the composite node.
You need to go to Compositing, here you need to connect the render layer image to the composite node


I suspect this has something to do with the size of your object - perhaps the images we are looking at are at least 400% bigger than what you hope to print? If that is the case the image might look distorted but is correct for the resolution that it is actually printing.


How to create a flare lighting up the background

Firstly, that sphere is not lighting up the background. The background appears to be an HDRI and the HDRI lights the scene, the scene does not light the HDRI. The effect that you want is glow (aka bloom).
If you are in Eevee then you can give that sphere an emission shader and turn on bloom. and that is the only step. If it does not appear change the emission value or change the values of the bloom.
If you are in Cycles there are two options (probably more, but these are what I know).
First way is to give it an emission shader set to any ammount and set the render passes to include Emission. Then in the compositor use a gleam node set to something like fog glow.
The second way is to render it twice (this is the slow method unless you have a good computer or little geometry). Render it once in Cycles for the high quality render and again in Eevee (at the same resolution and settings except maybe samples which can be turned down). In Eevee set the render passes to include bloom. In the compositor combine the Eevee bloom pass with the cycles render with a MixRGB node set to screen or add.


How to make an object emit light streaks

This can be done through compositing
you can do this in blender itself by adding glare node and switching to streaks and some few tweaks
another way is switching to any compositing software like after effects and add lens flare manually like in after effects optical flares is the perfect option.
Earlier there was a Add-on in Blender itself that was giving a facility to provide you a lens flare but after releasing 2.8 version of blender this add-on lost somewhere
I mean developers did not updated that add-on to 2.8


You have brightness set to 1 on both of your bright contrast nodes, it should be 0 as you don't want to modify the brightness at all, increasing the brightness like this is effectively setting the background density to a value above zero, so the whole cube is being rendered.

In fact you don't even need those nodes at all

The other thing I noticed is the top attribute node should use the density attribute for the smoke, rather than the flame attribute.

In order for volumetric materials to render correctly you will also need to go to the light paths section of the render settings and set the number of volume bounces to something reasonable.


how to render an image without effect of scene world

What happens when you check/uncheck the Scene World option, is that blender toggles between the lighting you have set up yourself, and a pre-built (and hidden) HDRI that provides lighting and reflections (as seen by default in the Shading Tab)
So, to get the same look for your render , what you are looking for is the effect of HDRI lighting. Go to the world section of your shading tab and add and Environment Texture (not an Image Texture). You can use any HDRI you want, but the one that is being used in your example is in your blender folder at ....2.92/datafiles/studiolights/world and the image is forest.exr (there are others there too). You can also find many free ones online - one of the most popular places is HDRI Haven (https://hdrihaven.com/hdris/).
If you want the lighting and reflection influence but don't want the image as your "background", you can mix the Environment Texture with another Background (I used the default) using the Is Camera Ray output of a light Path node as a Mix Factor (as shown below):


Strange behavior when going to Edit Mode

The half of the 'body' mesh is just hidden. You have to unhide it. Press ALT+H. The cyan point may be the matter of changed settings in 'User Preferences' (CTRL+ALT+U).


There is not such feature for now, but ... specifically speaking about Thickness there is an OSL shader by Róbert László Páli, which use the same type of measurement - depth along the normal of the surface.
Mesh Analysis - Thickness
with values Minimum (Red) = 0, Maximmum (Blue) = 1

OSL Shader
To set the same distance use Map Range node From Min = 0, From Max = 1

Thanks to Robin Betts for pointing me to Róbert's thread.


Is there a way to lock bones property from getting keyed. In Auto Key mode?

In the Blender User Preferences there are options under the Editing tab for Keyframing. Have you tried the Only Insert Needed toggle or the Only Insert Available toggle? That should solve your issue.


Rotate end face of Cylinder keeping cylinder diameter

You're probably looking for the Shear tool, shortcut AltCtrlShiftS (mh yes, you'd better not have lost a finger), it will make the selection slide on the X or Y (it's View orientation by default), then press 1 or -1 to get a 45° or -45° angle (the value is an Offset, not an angle, as you are not doing a rotation, you are sliding the vertices on an axis). Open the Operator box to enter or modify the values manually:


Blender 2.82 - 2D Grease Pencil Colours seem dimmed in Renders?

Answer - Thanks to Leander for the advice, the default Filmic colour space in Colour Management had to be set to Standard for the render to come out correctly.

One thing else to check, if you are setting up a Grease Pencil object from scratch and light is having an effect on the color: With the grease pencil object selected, inside Properties panel, go to the Object Data Properties tab. It's the tab that uses the green squiggle line.
In the tab, you should see your Layers expandable menu. Expand it and look below the Opacity slider, you'll see a checkbox called Use Lights. If you click this off, your grease pencil object will display colors as expected, if you leave it on then you can light the grease pencil objects using a normal light source.


you can change the appearance of your bones to boxes called b-bones.

with Ctrl Alt S you can change the thickness of the b-bone in edit mode.
And If you want to make your bone see trough, go to your object properties and under Display, change the maximum draw type to wire

And Bones can affect their parents with the bone constraint: Inverse Kinematic.

Inverse Kinematic


Can I set the rendered viewport to be a lower resolution on a high resolution monitor?

Not at the moment I'm afraid. Until recently such high resolution screens were uncommon, and it was rarely a problem.

With the advent of high DPI displays, UHD resolutions and 5K monitors the resulting pixel dimensions of a viewport are becoming a more common issue for live rendered preview, since it requires a lot of resources to render at such potentially high resolutions.

There are plans to support this in the future, and upcoming versions of Blender 2.8 already address the issue.

As stated in the wiki release notes page, introduced by commit 66c1b23aa10d there is now a viewport performance setting called Pixel Size which allows setting a scaling factor for the rendered viewport previews to a different resolution, to keep responsiveness at acceptable levels.

For the time being, in stable version of Blender the only workarounds are to either use Render Border to render a subsection of the canvas; or when inside a camera view, zoom it out in the 3D view, so the effective camera frame is smaller on screen resulting in less area to render.


How to make a physics simulation permanent

First off, go to the target frame and make sure only your pebbles are selected.

In the 3D Viewport, under Object > Rigid Body select Apply Transformation. This will make the current position the pebbles' starting one.

Then, in the same submenu, click Remove to remove the pebbles from the Rigid Body simulations; that is, to make them simple, static meshes again.


How to mirror the contraints rotation and limit rotation?

To do what you want it will be easier to use python. I wrote a script that copies constraint from bones with ".L" to corresponding bones with ".R"

import bpy
context = bpy.context
scene = context.scene
arm = bpy.data.objects["Armature"]
bpy.ops.object.select_all(action='DESELECT')
arm.select = True
bpy.context.scene.objects.active = arm
bpy.ops.object.posemode_toggle()
bpy.ops.pose.select_all(action='SELECT')
all_bones = bpy.context.selected_pose_bones
for bone in all_bones:
    bpy.ops.pose.select_all(action='DESELECT')
    if ".L" in bone.name:
        boneL = arm.data.bones[bone.name]
        boneR = arm.data.bones[bone.name.replace('.L','.R')]
        boneR.select = True
        boneL.select = True
        arm.data.bones.active = boneL
        bpy.ops.object.constraints_copy()
        bpy.ops.pose.constraints_copy()
        for con in arm.pose.bones[boneR.name].constraints:
           con.subtarget = con.subtarget.replace('.L','.R')

Another way to do it without Python is to use the Copy Constraint, which involves manual work to be done, you select an object then add a Copy Constraint, then select which other object you want to copy the property from (location, rotation). So no need for paste constraint.


Bezier Curve: Bevel Object is creating a flat surface

Please rotate the shape named [Cube]  in

[Edit Mode]

90 degrees on some axis. The results should be interactive.


I managed to work out the issue.
It’s a user error rather than a blender issue.
I found that when I created the first copy I had a clip in the video editor, which then got copied across to the new scenes.
I didn’t spot it because I’d deleted the clip from the video editor after I’d made the scenes.
Soon as I removed the clip , then the renders started working again.
Interesting lesson learnt lol


I made a mistake and moved a surface texture

I think you have just moved down a tris of vertices. Select them and grab it on the Z axis with snap to vertex active as in the following pictures:

Moving faces in the 3D view don't interfere with their UV data, so the texture should come back to his initial state (not streched) without further operations.


Blender 2.8 Texture coordinates keyframes are not visible in Graph Editor

I have 2 options for you.

1) You need to select the object AND the node that you want to animate. It should now be visible in your Graph editor.

2) You need to disable the "Only Selected" icon in the Graph Editor (little icon arrow).
See picture


As others have stated, I need to add more geometry to deform around the curve:


Overview:

I think that everything should be ok with just Bump node. There is a method to convert Height Map (B&W) to the same Normal Map as in your first image, but this produce the same results.

Comparison:

First my node setup:

  Bump_to_normal group is not mine, see Credits at the bottom.

In Texture Group Node there is Height Map created from Voronoi Texture.

Bump node:

Bump_to_normal node:

As you can see there is no difference at all, no matter from what map you feed Normal input in Glass node.

Solution:

I think your problem lays just in Distance value in Bump node. It's to high.

About Bump to Normal:

I can't tell you how this node setup is working, there is little to none info from the author (check Credits). But I'll show you how to set it up:

In Texture Node Group > Height Map Image set your Height map. It could be any B&W input. Image Texture, Texture Paint, Procedural, you name it.
Connect Bump_to_normal Node Group to Normal Map and then just to any Normal input you want.

Blend file:

Credits:

First of all this is not my work, it's from riceart41 on BlendSwap (download this file to make all of this to work). You can find more information on YouTube and on BlenderArtists.


Blender to Unity animation | Volume Preservation

From Cygon4's post (Feb 16, 2016)

  [...] the "Preserve Volume" option (= dual quaternion skinning) does not exist in Unity.

You have to find a weights only method to preserve your volume. A common practice is to use a helper bone at angled areas.

Create the chain of bone1 and bone2.
Create bone1_helper and parent it to bone1.
Constrain the rotation from bone2 to bone1_helper, use local space and an influence of 0.5.

The gif showcases the base model, then Preserve Volume option, then the helper bone option.

Bake the animations with visual transform before exporting.


With Pivot Center set to 'Active'..

in Edit>Face mode, select the face you want to flatten to
hit CtrlAltSpace to create a Custom Transform Orientation from the face. (Check 'Use After Creation' and, if you don't want your custom orientations to hang around in a list: 'Overwrite Previous')
in Edit>Edge mode, select the edge-loop around the hole
in Edit>Vertex mode (the hole edge-loop should still be selected, as vertices), also make one of the vertices on the orientation-face active, by Shift-selecting it last.
hit SZZ0, to scale the all your selected vertices to 0 along the normal (the local Z-axis) of the face defining your custom orientation, centered on the active vertex.


Front Flip Animation Messed Up Due To Quaternion

Switch to pose mode and find and select the bone that rotates backwards. Go to the last keyframe in your animation (frame 80 it looks like), and negate the W, X, Y, Z of the rotation in the Bone Properties panel, ie. replace 0.1 with -0.1. Insert a keyframe to save the values. Your rotation should now work.
(I think there's an op that will do this automatically but I can't remember what it is...)


are you looking to make a hole? try the boolean Modifier, difference, apply and remove the cilinder (and good luck with Ngons and strange things if your planes are not 100% flat).


You can directly use color in surface socket

The color will show up directly in render mode (both Render and DevLook)

And for alpha channel, the original alpha in RGB mode can't be the value in surface(might be a bug?) .An alternative way is use transparent shader with mix shader instead as shown below:

the factor of mix shader can be the alpha value.
Blend mode in Material setting should set to one of the alpha options
Show backface will cause some problem, toggle it to see which one suit the scene

There might be a better way on this task


Probable causes of noisy renders:
(click on the links in blue)

Render Samples set too low 100 samples might just be too low for what you want, try a higher value.

Here's the scene at 800 samples:

Samples set on render layer override regular sample settings.
Lights or environment not set to multiple importance. Aditionally this link
render resolution is set to less than 100%
Use branched path tracing instead of the default samples

Bring up the AA samples and then set the values for each type of sample according to the materials in your scene. Note that each of this values is multiplied by that of the AA Samples. (for example 4 diffuse will turn into 500 samples when the AA value is set to 125)


The 'Normal' output of the Texture Coordinate node is in the Object Space of the shaded object. The 'Object' output defaults to the space of the shaded object, but can be overridden to another object's space, using the 'Object' field at the bottom of the node.

We need the dot-product of the direction of the normal at the shading point in World Space, and the vector from the lamp-object to the shading point, also in World Space (which is the normalized position of the shading point in the lamp-object's space, if the lamp-object is not rotated or scaled non-uniformly).

It's also nice to map the full range of the possible dot-product results from (-1,1) to (0,1) to feed the color ramp.

So this is a possible setup, with the rotations and scales of whatever object you are using as a lamp locked off to (0,0,0).

..with this sort of result:


FBX shaders messing with materials when importing to Blender

That color only indicate that Blender cannot find a texture map.

Has been moved to a different location
The connection is lost
If there are more than one texture image if you reload the texture looking in the proper folder, Blender will update the rest of the texture locations.


Just disable the "Manipulate Center Points" with the icon or by pressing Alt, (comma).


How to compile Blender from source on OSX?

The Blender documentation page https://wiki.blender.org/wiki/Building_Blender/Mac contains instructions on how you can compile Blender for a Mac machine. Note that the instructions below might not be as accurate anymore since lots of things might have changed.

But they don't quite work. When you get to the line "make", make fails, because the CLANG compiler that comes with XCode can't process "openMP" library.

Instead you need to use a specially built version of CLANG that DOES support openMP. (openMP pertains to threading on multiprocessor architectures, if you're curious. It is bad of Apple that their CLANG compilers behind with this.)

As you can see from that page, you pull the blender source code from git, and a bunch of already compiled binaries from SVN.

piBookAir:darwin-9.x.universal pi$ pwd
/Users/pi/Dev/Blender/blender-build/lib/darwin-9.x.universal

piBookAir:darwin-9.x.universal pi$ ls
README      freetype    opencollada osl     sdl
boost       gettext     opencolorio png     sndfile
clang-omp   jpeg        openexr     python      tiff
ffmpeg      llvm        openimageio release
fftw3       openal      openmp      samplerate

As you can see from the listing, it contains this special clang-omp

So you could probably make sure that that is getting found in your path before the existing CLANG, and it will work.

I haven't tried, because Jens showed me how to get it working using SCons.

SCons and CMake are two different ways of automating the process of setting up the build. if you're familiar with AutoTools, you can think of CMake as being AutoTools brought up to date in a way that works nicely on Windows systems also. And SCons does the same thing but using Python.

Now the big difference is that CMake is an actual program you have to download and install on your system, whereas SCons is just a Python script.

To me that makes SCons a clear winner, and it is indeed painless to do it this way.

So, create /pathto/blender-build/blender/user-config.py as follows:

CC = '../lib/darwin-9.x.universal/clang-omp/bin/clang'
CXX = '../lib/darwin-9.x.universal/clang-omp/bin/clang++'

And then run:

sysctl hw.logicalcpu

to find out how many CPUs new machine has (my MacBook Air has 4, a modern MacBook Pro has 12)

Now:

cd /pathto/blender-build/blender
python scons/scons.py -j4

And grab a cup of tea (or 4 if you forgot the -j4 parameter)

Now you should have:

/pathto/blender-build/install/darwin/blender.app


Your mist settings are bad. To see it, select the camera and check "mist"

You can change this in world settings


How to make simple Fresnel in blender Open Shading Language?

The OSL global variable you're looking for is I

From the docs:

  vector I

  The incident ray direction, pointing from the viewing position to the
  shading position P.

So, what's called 'View Dir' in your illustration is -I

Note that the 'viewing position' is the origin of any ray, not just those originating at the viewpoint/camera

EDIT: however, this is the shader which works as you expected in your post:

shader naive_fresnel(

           normal Normal = N,
    output  float  Fac = 0.0

)
{
    Fac = 1.0 - dot(normalize(Normal),I);
}

... which means I must be pointing towards the viewpoint? (BTW, the dot-product produces a scalar value, not a vector)

Loosely speaking, to Cycles, being physically-based, everything is a light, either directly, by emission, or indirectly, by scattering or reflection.

In standard use, how rays are actually cast is down to the integrator, not the shaders. OSL provides no direct access to the direction to lamps: the notion is that this kind of 'fake' is not required, or desirable, in a physically-based renderer.


From the development team:

  Flamenco is undergoing some changes right now, so I would recommend
  you wait with testing it out. Please check out the website again in a
  couple of months, or follow what we are doing on cloud.blender.org to
  spot any news in Flamenco development.


How to emit hair particles according to the normal of the emitter face?

This is caused by weights to some degree - as weights are added to vertices they are interpolated on the faces sharing those vertices. Hence mesh in the file above doesn't have vertex group affecting only top face rather top face plus part of faces below:

Particles will appear everywhere where weights are more than 0 which in this case includes top part of side faces as well. The proximity there will be less but enough to prevent from clear emitting only from the top.

One thing to try is to inset top face and weight paint only it:

This should guarantee particles disappearing from the sides but will still allow appear more than one around the top face as now weights are interpolated around the face which was insetted:

Hence Particle per Face won't really work here.
Another way is to join that Ngon into vertex at center and emit from vertices:

Likely the best way is making several particle systems and using each one for every special case.
Or using dupliverts / duplifaces, where there will be object duplicated via dupliverts instead of particle system. As dupliverts allow less control over position / randomizing / rotation etc. it could be used only for cases where strict rotation is acceptable.


Just go into User Preferences [CTRL+ALT+U], then select the Themes tab, and then Text Style on the sidebar.


Baking high poly model texture to low poly model (2 models)

There are a few possibilities, so here's a checklist to go through:

--Selections. I know it seems obvious, but it's actually pretty easy to accidentally deselect something, and it's not always obvious when it happens. Make sure your image texture, the one you want to bake to, is selected, and the only thing selected, in your node editor. In the viewport, check to see if you selected your high-poly object first, then your low-poly object second (click the first, shift-click the second). You can't do this with box-select, it won't have a proper active object. If you're having trouble doing this in the viewport, you can do it via the outliner window (the little one that lists all your objects in the top right).

--UVs The reason it's usually done with the same object is because Blender tries to follow the UV layouts when baking. While it doesn't have to be the same object, the UVs of the low-poly should be laid out in roughly the same way as the high-poly, so it'll show up on the right places in the texture. For example, if it were a character, the face of the low-poly character should be unwrapped to the same location as where the face of the high-poly character is unwrapped.

--Images Make sure you've named and saved your target image to your computer before baking. If you don't do this, Blender doesn't know where you want that information to ultimately go, because you don't have a physical file selected. This makes sense when you realize baking works by essentially overwriting existing information, rather than creating entirely new information from scratch. At that point, it'll only be a big black square, but Blender will overwrite it with the map you're after as you bake. Just make sure to save a second time after, too! Blender won't remember your changes for you, when it comes to external files. In addition, make sure the textures of your high-poly have been appropriately uploaded, as well. It can be easy to confuse object color, which can be baked into a file, with what the actual texture looks like.

I hope this helps! Happy Blending.


External commands sent to Python Interactive Console?

If running the exe works, you could also open the blend with blenderplayer and not worry about exporting.

os.system('/path/to/blenderplayer.exe bob2.blend')


Procedural texture for longitudinal lines

Radial Gradient texture as Texture Coordinates

This Texture node place a Radial Gradient upon the object's surface, creating a variation of factor from 0 to 1 around the origin of the object (using Object Texture Coordinates).

If we use the resulting factor of the node as the X input of the vector driving the mapping of a wanted coordinate, we are able to place the wanted texture with a new set of coordinates.

X (canonical name should be U) is the coordinates that read from left to right the texture and should be mappad with the gradient (see Combine XYZ node).

Y (canonical name V) should instead start from bottom to top, so it's equivalent to Generated Texture Coordinates's Z. You can extract it with a Separate XYZ node.

Here's the resulting shader (with a 45°-rotated Wave Texture) upon a cone, a fat Suzanne and a shell:


Having trouble implementing a function in the node editor where the source uses if/else logic

Rewrite the code as
h1 =     (g - b) / delta;  // between yellow & magenta
h2 = 2 + (b - r) / delta;  // between cyan & yellow
h3 = 4 + (r - g) / delta;  // between magenta & cyan

h  = (r==max) * h1
h += (1 - (r==max)) * (g==max) * h2
h += (1 - (r==max)) * (1 - (g==max)) * h3

where (X==Y) means 1 if X and Y are equal, 0 if they're different (ie. what the "Compare" operation on a Math node does).
This is just a bunch of arithmetic operations, so it's straightforward, albeit laborious, to translate into nodes.
edit
Here's how I did it with nodes. This does
tmp = (g==max) ? h2 : h3;
h   = (r==max) ? h1 : tmp;

The If Then Else node can be done with a lerp


Ok so the problem was not the format but your node organization, it's a bit messy, choose one of those below. Also make sure that you've correctly unwrap your object and that the different parts have the right material.


How to make particle systems of particle systems?

I know of no way to be able to make a particle system with particle systems underneath.  However, there is a way you can convert the flower particles into mesh.  You have to start by applying any modifiers that are given to the objects being used in the particle systems applied to the flower.

Then you select the flower, go to the modifiers tab in the Properties bar, and click the convert button on each particle modifier.  The particles are now converted into a mesh.  Now join the petals, nectar stems, and sphere together so it's all one mesh.  Now you are able to make a particle system that uses this flower.

This does make the flower have more vertices, so you may want to go try to reduce the number of vertices to save memory.
Hope this helps


edges.new - Edges Not Adding Correctly (black not solid orange)

Look like you are creating 2 new vertices per line, that's creating disjointed segments. Instead, just create a new vertex, then the new edge between the previous vertex and the new one, etc...


How do I export audio in a video that is purposefully loud and distorted? (VSE)

Figured it out! It turns out that I need to set the audio codec to MP3, NOT AAC.


Why does it displays a kernel error message whenever I try GPU rendering in Cycles?

It seems to be a problem with the Radeon RX cards if I understand this bug report correctly, updating the card drivers can help in some but not all cases as far as I've read:
https://developer.blender.org/T83130


How to change camera movement speed on Path during animation

Make Sure you create Keyframes for the Offset value in the Follow Path Constraint.

Insert Keyframes on the [Follow Path Constraint].  Use [Fixed Position] TRUE.  The image belows shows two keyframes in the timeline and the dopesheet.

By using keyframes to directly and easily change position, you will change the speed, usefully and indirectly.  The object can also stop moving by using the same value of keyframe at two different frames. You can also reverse direction. You will be specifying the positions (0 = start, .5 = mid, 1.0 end) along the curve.  There is no direct settings for distance per frame and this is not a large problem under many scenarios.
There are also many tutorials at video sites that will visually explain this.  Consider searching Blender Tutorial Follow Path Constraint.


How do unparent my model from plain axis(object) while keeping rotation

Press ALT+P and choose " and Keep Transformation" from the drop down menu.


Select the animated object and copy strg+c all the key frames in the Dope sheet editor
Set key frame on all channels were you want to paste on your target object. otherwise, you cant paste there.
Paste strg+v your key frames on the target object
Since you pasted the location of object on your objects are now inside each other. You most likeley want to tweak the animations in the graph editor.


Is there an easy way to make two flat objects coplanar?

Define a plane by a point on the plane and its normal.
For example sake using 4 coordinates of plane as 4 points that make up the plane.
>>> ob = C.object
>>> ob
bpy.data.objects['Plane']

>>> mw = ob.matrix_world
>>> points = [mw @ v.co for v in ob.data.vertices]

Only need 3 points, $(a, b, c)$ to define a plane. All of these distinct points is on the plane. The normal is the cross product of any two non parallel vectors on the plane (b - a).cross(c - a)
The global plane coordinate and normal of example plane.
>>> plane_co = points[0]
>>> v1 = points[1] - plane_co
>>> v2 = points[2] - plane_co
>>> plane_no = (v1.cross(v2)).normalized()

Hence to make any plane aligned with another plane can align their two normals. To get the quaternion rotation required to rotate one vector to align with another.
>>> q = plane_no.rotation_difference(plane_no_2)

Matrix math to translate, rotate, scale with respect to a pivot point in Object mode
Finally there is a helper method mathutils.geometry.distance_point_to_plane
>>> geometry.distance_point_to_plane(
distance_point_to_plane(pt, plane_co, plane_no)
.. function:: distance_point_to_plane(pt, plane_co, plane_no)
Returns the signed distance between a point and a plane    (negative when below the normal).
:arg pt: Point
:type pt: :class:`mathutils.Vector`
:arg plane_co: A point on the plane
:type plane_co: :class:`mathutils.Vector`
:arg plane_no: The direction the plane is facing
:type plane_no: :class:`mathutils.Vector`
:rtype: float

which will give how far along the plane normal a point on another plane is to current plane.
Have used this in determining coplanar faces here https://blender.stackexchange.com/a/53976/15543.


How can i add a text help window and a help button into the 3D View?

Been playing around with bgl visualizations for sounds. Used a non modal approach akin to https://blender.stackexchange.com/a/40676/15543  Later on decided it would be nice to have some way to hover over and display information.  Left clicking involved having to keep tabs on the 3dcursor.

Here is a stripped down but working version of where I got to with hover.  Meant to get around to giving "buttons" a state eg mouse_over etc but... Also an alignment eg (TOP, MIDDLE, BOTTOM) (LEFT, CENTRE, RIGHT)

Uses screen area indexes to keep tabs on which area to show help screen.  Button is white when initialised, blue when mouse in area and red when hovered over.  The green help window appears when hovered over.

The modal operator is invoked with 'INVOKE_SCREEN'

Note: you can save settings to the screen datablock, which is a nicely away from prying.

import bpy
import blf
from bpy.props import IntProperty, FloatProperty
import bgl

class BGLWidget:
    handle = None

    def __init__(self, op, context, areatype):

        # Calculate scroller width, dpi and pixelsize dependent
        self.pixel_size = context.user_preferences.system.pixel_size
        self.dpi = context.user_preferences.system.dpi
        self.dpi_fac = self.pixel_size * self.dpi / 72
        # A normal widget unit is 20, but the scroller is apparently 16
        self.scroller_width = 16 * self.dpi_fac

        self.op = op
        self.areatype = areatype

        self.handle = self.create_handle(context)
        theme = context.user_preferences.themes[0]
        self.theme = theme

    def create_handle(self, context):
        handle = self.areatype.draw_handler_add(
            self.draw_region,
            (context,),
           'WINDOW', 'POST_PIXEL')
        return handle

    def remove_handle(self):

        if self.handle:
            self.areatype.draw_handler_remove(self.handle, 'WINDOW')
            self.handle = None

    def draw_region(self, context):
        # check validity

        self.visualise(context)

    def draw_box(self, x, y, w, h, color=(0.0, 0.0, 0.0, 1.0)):
        #bgl.glDepthRange (0.1, 1.0)
        bgl.glColor4f(*color)
        bgl.glBegin(bgl.GL_QUADS)

        bgl.glVertex2f(x+w, y+h)
        bgl.glVertex2f(x, y+h)
        bgl.glVertex2f(x, y)
        bgl.glVertex2f(x+w, y)
        bgl.glEnd()

    def visualise(self, context):
        # used to draw override in class def
        pass

class Button:
    def __init__(self, x, y, w, h, color=(1,1,1,1)):
        #draw a box
        self.x = 0
        self.y = 0
        self.w = w
        self.h = h
        self.color = color

    def __str__(self):
        return "Button %s" % str(self.color)

    def __repr__(self):
        return "Button %d %d color(%s)" % (self.x, self.y, str(self.color))

    def in_box(self, x, y):
        return (self.x < x < self.x + self.w
                and self.y < y < self.y + self.h)

class ButtonWidget(BGLWidget):
    help_screen = -1
    buttons = []
    screen_buttons = {}
    def button(self, w, h):
        # add a new button
        b = Button(0, 0, w, h)
        self.buttons.append(b)
        return b

    def visualise(self, context):
        if self.help_screen > -1:
            print("HELP", self.help_screen)
            if context.screen.areas[self.help_screen] == context.area:
                self.draw_box(0, 0, 10000, 10000, color=(0, 1, 0, 1))
                context.area.tag_redraw()
        for b in self.buttons:
            self.draw_button(b, context)

    def draw_button(self, box, context):
        m = [i for i, a in enumerate(context.screen.areas) if a == context.area]
        if not len(m):
            return None
        key = "area%d" % m[0]
        b = self.screen_buttons.setdefault(key, Button(box.x, box.y, box.w, box.h, color=box.color))
        b.x = context.region.width - b.w - self.scroller_width
        b.y = context.region.height - b.h - self.scroller_width
        #print(b.x, b.y, b.w, b.h)  # debug shows box coords on draw
        self.draw_box(b.x, b.y, b.w, b.h, color=b.color)
        #self.screen_buttons[key] = b

    def mouse_over(self, screen, area_index, x, y):
        key = "area%d" % area_index
        box = self.screen_buttons.get(key, None)
        if box:
            area = screen.areas[area_index]
            if box.in_box(x, y):
                box.color = (1, 0, 0, 0)
                self.help_screen = area_index
                area.tag_redraw()
            else:
                self.help_screen = -1
                box.color = (0, 0, 1, 0)
            #self.screen_buttons[key] = box
            area.tag_redraw()

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

    def modal(self, context, event):
        def in_area(area, x, y):

            return (area.x < x < area.x + area.width
                and area.y < y < area.y + area.height)

        screen = context.screen
        mx = event.mouse_x
        my = event.mouse_y
        #print(mx, my)
        areas = [i for i, a in enumerate(screen.areas) if a.type.startswith('VIEW_3D')
                 and in_area(a, mx, my)]

        for i in areas:
            a = screen.areas[i]
            region = a.regions[-1]
            x = mx - region.x
            y = my - region.y
            ui.mouse_over(screen, i, x, y)
            if event.type == 'LEFTMOUSE':

                print('PRESS in screen["%s"].areas["%d"]' % (screen.name, i))
                #click events ???

        if event.type in {'ESC'}:
            # dont have to remove the UI here

            ui.remove_handle()
            return {'CANCELLED'}

        return {'PASS_THROUGH'}

    def invoke(self, context, event):
        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()

    # create a UI
    context = bpy.context
    h = 50
    w = 200
    ui = ButtonWidget(None, context, bpy.types.SpaceView3D)
    button = ui.button(w, h)
    for a in context.screen.areas:
        if a.type == 'VIEW_3D':
            a.tag_redraw()
    bpy.ops.object.modal_operator('INVOKE_SCREEN')


Boolean Difference Acts like Boolean Intersect

A little more experimentation after getting over being stumped, and I have found the answer.
It was indeed the overlap of surfaces. If two surfaces of two objects are exactly aligned, boolean operations can result in ... unexpected behaviour.
I moved the subtraction object by .01m and it worked fine after that.


Bones aren't grouped perfectly when I rotate them two times on the X axis

I found the solution to this problem by myself. I have to rotate the z axis on the top.


It is a mission impossible to edit a video

This has been a problem in blender for quite a while. Definately not a 2.8 problem. Not quite the optimal solution but it works is to turn the video into an image sequence and then import it as an image sequence. I usually use ffmpeg to convert the video into an image sequence but I don't know how easy that is from a non unix pc. You can always just import it into blender and export it as an image sequence. I did recently see what I think is a big improvement in the 2.8 video editor where I think this problem is fixed allthough I can't conferm because it crashed 1 second later.
A different problem which I don't think you are describing here would be just a framerate mismach so make sure your render settings fps is the same as that of your source video.
(If the fps counter is red the problem is probably the first one I mentioned, could still be both though)


There are several issues with your file:

The object origins are not centered. The origins are used to calculate the center of mass, which means that they can result in strange behavior if they are not correctly centered. Press CtrlShiftAltC> Origin to center of mass to snap the origin to the center of mass.

The intersecting concave links are using the Convex Hull collision shape. Because the hole in the middle of each link is a concave shape, the links then collide and fly apart. To the simulator it appears as if the links are inside one another.
However, note for a chain I recommend using Constraints instead.

Some objects have unapplied transforms. In many cases applying the scale and rotation can improve the stability and behavior of a simulation. Just beware when applying transforms to animated objects.

Animated is not enabled on the capstan. Enabling this is important if you want to control rigid bodies with the animation system.

Setting up Constraints for a chain:

Select all the links in the chain.

Press Connect in 3D View > Tool Shelf > Physics > Rigid body tools, then set the constraint type to Point (sort of a ball joint) and the Connection Pattern to Chain by distance:

By default the new constraints (added to the empties) will have Disable collisions enabled which disables collisions between objects constrained to each other. I recommend leaving this setting on, and keeping the collision shape on Convex Hull as nothing besides the links themselves are likely to try and pass through the hole.

 (For Blender 2.8)


I have done everything...
Please what's your email?.

I pressed the ALT H & everything vanished from screen including my character..

I have opened the Armature and under the pose mode set up few bones but single bone not on character.. changed the viewpoint to Infront but still.(check the picture)not good picture I know.

Or is it because my Character has a bigger head, I'm unsure


In a fluid simulation, how can I make an "inflow" fluid type pour into a "fluid" fluid type in one simulation?

Just make a longer animation, where you pour some water until your pool has enough inside, then stop the inflow with a keyframe and start it some time later. Then, only use the needed timeframe.


Dark, Unwanted Shadows Between 'leaves' when Rendering in Cycles

I'm posting this just so I can post the pic. You can try this setup and see if it works. It should have a good effect, yet it doesn't seem to do much when I look at it. However, as you can see from the photo, the texture is missing in your blend file so everything is pink. This might affect how the setup is working on my end. Have a try on your project and let me know if it helps.


how to use vertex group to instance an object in geometry node?

Each vertex has a weight from each vertex group available attribute:
If we create a cube with a vertex group lid, each vertex gets a new attribute "lid" that contains the vertex weight:

Then we can multiply the scale of each point by this vertex weight and create our instances on all vertices:


How can a body transition between soft and rigid during animation?

As LukeD's comment suggested, you can animate the soft body stiffness.

I you want to key the rigid part yourself, use the soft body goal and animate its stiffness value.

Resulting in a transition between manually keyed animation and soft body simulation.

You can also animate the push and pull for the Soft Body Edges. Here, I animated them from low values (0.2, 0.4) to 0.999.

As you can see, in them second example, the object's origin stays motionless as it has no animation.


The comment from lemon is what i thought too. Take a default cube, subdivide it good and well, then "Transform -> to sphere -> 1.0"
The UV map on the cube should still be squarical, and be able to map.
The other way is messing with UV unwrap and trying "cube projection", but IDK enough about that to help you.


Mesh distorted when armature bone rotates

Try to weight paint only the arm and not the rest of the body. The problem may also be that the armature bone is too short. This will make the rig to be in imbalance and this kind of problem occur. Good luck! You can link the .blend file here is it doesn't work.


Geometry should not be an issue here, glass shaders are noisy by nature and will probably have a bigger impact in your scene. If you use this technique and take advantage of instancing feature the memory consumption benefits should help mitigate the number of objects.

Make a simple box mesh with the desired dimensions of your brick, make sure you apply the scale.

Add three material slots with the following order: Clear Glass, Mortar, Frosted Glass.

Create materials accordingly as desired and assign clear glass to both front and back faces, and mortar to the remaining four rim faces around them. Two simple glass shader with different roughness values should suffice for both glass materials.

Now add two modifiers. One Solidify with the desired thickness; adjust the material offset to $2$, so the inner layer becomes all frosted glass.

Now add a Bevel modifier, to add some roundness; adjust radius as desired.

Now array the bricks with whichever method you like.

Either use an Array modifier: Quick and simple, no optimization and higher memory use.
Manually duplicate the object around: Instancing gives memory benefits, but ads lots of individual objects which may slow down the viewport and pollute your scene, making it harder to manage.
Use a particle system/Duplifaces. Array a simple plane and use either particles or duplifaces to distribute bricks along the faces. Harder to setup, memory benefits, and less individual objects to manage in the scene, but may still slow down the viewport.


No audio playback in VSE but rendered file has audio

To enable the sound in my Video Sequencing Editor, I had to change the system setting for audio device from OpenAL to SDL. Doing this seemed to jar loose the sound so that it would play.  I was even able to change the setting back to OpenAL and the sound continued to be enabled.  Strange, huh?  The sound works fine now.

Go to File> User Preferences> System> Sound: Audio Device.


What does the radius vector do on an SSS shader?

From the Blender Internal Wiki:

RGB Radius:
This is not in fact the radius of the subsurface scattering, but the average path length between scattering events. As the light travels through the object it bounces around then emerges from the surface at some other point. This value corresponds to the average length the light travels between each bounce. The longer the path length is, the further the light is allowed to scatter.
This is the main source of a material's perceived "scatter color." A material like skin will have a higher red radius than green and blue. Subsurface scattering is the diffusion of light beneath the surface. You control how far the light spreads to achieve a specific result.

Basically you change the radius value for each of the three primary colors, which results in the efects you described in your question. In both render engines the Radius value does fundamentally the same thing.
The Cycles wiki states:

Radius input:
Scattering radius for each RGB color channel, the maximum distance that light can scatter.

This is fundamentally the same as the Blender Internal engine.
View the entire entry on the Blender Internal SS Shader.
View the entire entry on the Cycles SS shader.


Why are files so small after linking objects?

When you are choosing to link data between objects you are telling Blender that these objects share the same data. It's not just that when you edit one object Blender will edit the other object to match, it's that they both reference the same data.

To explain this further, imagine 3 objects, each with their own object data:

You can think of this as 6 units that Blender has to save: 3 object data blocks and 3 object blocks.

Now, if were were to link the data of these three objects it would look like this:

Now there are only 4 units Blender has to save: 1 object data block and 3 object blocks. Obviously, only having to save 4 instead of 6 blocks of data will result in a smaller file.

The more objects that share each other's data, the more memory is saved.

When objects that share data are joined, you can imagine Blender first separating all the data so each object has its own object data (like image 1) and then joining the objects together. Yes, that would result in only 2 data blocks (1 object and 1 object data), but the object data would now contain 3 times the number of vertices (from merging the 3 separate object data blocks), resulting in the file size going back up.

To summarise, if objects are using linked data, the data is shared so the file will be smaller, but when objects are joined, any memory sharing is lost as all vertices (and any other data) are joined into one object data block.

There shouldn't be any trouble with using linked data in another scene, the only issue that can occur is forgetting the object is linked, editing the object and then realising all the other objects have now been edited, which might have been unintended.


Light Setup and Shaders
In order to achieve a similar look, the most crucial part is setting up the lights (as always). Add 3 large Area Lights along with a soft rounded backdrop (typically used for classic studio photography) to the scene in order to get similar reflections as well as soft shadows:

The larger the area lights, the softer the resulting shadow on the ground
To replicate the shader(s), all you have to do is figuring out a proper rougness value and set the reflection (specular) to 1. Tipp: The roughness value for plastic is about 0.2 - 0.3 according to the manual:

Roughness set to 0.01 (left) vs. Roughness set to 0.3 (right)
Fake Motion Blur
You can fake the Motion Blur on top of the pins, by splitting up the scene into View Layers (backdrop, pins and bowling ball in this case) which allows to add the blur only to the pins in your favorite raster graphics editor of choice or even in Blender's Compositor:

Overview of potential view layers - All objects are set to 'Indirect only' for the 'backdrop layer' per collection and the background is set to 'transparent' for both object layers
If the later is an option, I'd suggest use a Directional Blur node on the Pin Layer also and also blur the result slightly, see: How to manually achieve a motion blur effect on a object in the compositor?

Real Motion Blur
In order to get realistic Motion Blur you would have to move/animate the pins in the scene and enable Motion Blur under Render Properties > Motion Blur and play with the shutter setting, which gets you a more realistic and especially photographic result:

Object animated in Z-Normal direction, 2 location keyframes added, Rendering of the second frame.
Further reading:

Achieving Motion Blur on a still image
How to Create a Vinyl Plastic Toy Shader?
How do I create a reflective white material?
How To Create 'Hard Plastic' Material?


Place the 3D cursor in the center
Add your empty and the cylinder you want to clone
Go to edit mode and scale and position your cylinder at the First position
back to Object mode and create an array modifier on the small cylinder relative to the Empty and bump count up to 3
Rotate the empty 90°

A lot like here.


You're making it very complicated, there are several ways to make your object, the simplest would be to bevel the angles of a rectangle. Then you may need to work the topology but it depends on your final goal.


Bounding Box faces relative to world coordinates

You can obtain the result you want by applying (eventually temporary) the rotations of your object.

To do that simply use Ctrl+A and choose 'rotation'.

Once the dimensions are obtained, eventually come back to the original orientation with Ctrl+Z