How do I make a walking and running sound?

Add another keyboard Sensor L-shift but make it inverted, connect that to the left side of the Controller linked to your walk sound Actuator but make sure its only W and the inverted L-shift sensors connected, that should keep the run sound but stop the walk sound if L-shift is pressed


Try using a curve as a bevel object.

1- Create a curve with the shape you want to use as bevel.

2- Create a different curve as a new object for the shape you want that bevel object to follow

3- With the newly created curve selected, go to the curve menu and select the curve you want to use as bevel object and adjust the bevel depth.


How to extrude edges outward based on multiple axes?

Once you've extrude, press enter, then try altS (Shrink/Flatten). You can play with some parameters on the bottom of the Tools panel (on the left of your 3D View, displayed with T).


"Object has no attribute" in Blender Game Engine

cont.sensors["mouse"] instead of cont.sensor["mouse"]


The UV map being shown in the UV Image Editor is the active one, accessible through uv_layers.active variable of active object's mesh data.

According to API docs, loops and all UV maps in uv_layers are aligned. Which means, if you have the indices of every selected MeshUVLoop within current mesh's UV map, you'll get the corresponding MeshLoop at the same indices within that mesh's list of loops. From there, you can get their vertices.

To make my explanation above clearer, here's a sample script that will print selected UV loops' vertex coordinates to console. The script won't work if use_uv_select_sync button in UV Image Editor's header is toggled on, in which case MeshUVLoop's select property is ignored.

import bpy

# UV data is accessible only in object mode
prev_mode = bpy.context.object.mode
bpy.ops.object.mode_set(mode='OBJECT')

# Update vertex selection properties, in case the script wasn't run in
# object mode
bpy.context.object.update_from_editmode()

# Active object assumed to be a mesh and already have a UV map
mesh = bpy.context.object.data
uv_map = mesh.uv_layers.active
selected_loops = []
selected_vertices = set()

for index, uv_loop in enumerate(uv_map.data):
    if(uv_loop.select):
        selected_loops.append(index)

for loop_index in selected_loops:
    selected_vertices.add(mesh.loops[loop_index].vertex_index)

for vertex_index in selected_vertices:
    print(mesh.vertices[vertex_index].co)

print('*' * 20)

# Restore whatever mode the object is in previously
bpy.ops.object.mode_set(mode=prev_mode)


Smooth shading gets ignored in cycle render

I dont know what it is, but the problem comes from the "use subdivision" in the "displacement panel" here.
At the bottom of the picture below, just uncheck "use subdivision".


Adding a response, because I came here looking for an answer.

Blender 2.80 (beta), as of 2019-feb-02 nightly build:

The parameters for a newly added primitive are not in the T-side-panel (as previously in Blender 2.79).

Instead they have a pop-up panel in lower-left corner overlaying the 3D-View.

When you first start running Blender-2.80, this pop-up may be minimized (as shown in the first image). Click this to open this panel. It may remain automatically opened for newly added primitives after you open it the first time.


Why can't I have two animations in one objects when using property play mode?

The attached BLEND file shows how this is accomplished.
The trick is to use three different actions added each to their own "NLA" tracks.

It's set up to use the GE, so use keys A, S, & D to control animation #1, #2, & #3 (#3 = #1 & #2 together).

The Blend File:


How to create and assign a group to an fcurve with python script?

Both the fcurves themselves, and the action groups are part of the action object. You have to create new groups through the action and then assign that group to any fcurves you want inside it.

armature = bpy.context.scene.objects.active
anim_data = armature.animation_data
action = anim_data.action

# create a new group
group_1 = action.groups.new("group_1")

# assign the first three fcurves to the new group
for fcurve in anim_data.action.fcurves[:3]:
    fcurve.group = group


Equirectangular projection and flattening horizon

I could be wrong, but it looks like you haven't UV unwrapped the sphere. This tutorial explains the process well.


The rigging is bad, the arm has too much influence on the shoulder while the chest should be the only one to have influence on it with this kind of armature. I've made some corrections and it works "fine". Note that you could create a shoulder (last picture), it would make the rigging better i my opinion:


What is the logic to having an axis labeled Z and also having Z refer to distance from the camera?

Quoting from iKlsR's answer:

  Blender uses the right hand coordinate system with the Z axis pointing
  upwards. This is common with the coordinate systems used by most
  common 3D CAD packages.

However, it's also a standard to use Y up for images (with Z as depth).

To help with getting used to it, you could try a couple things:

Imagine you are looking at the image editor top down instead of from the side.
Think in terms of the camera's local coordinates (the local Z is always out the front)


Whether or not you have just created it, if you want to make an edge-loop parallel to an adjacent one, slide the loop with GG. Now hitting E will make the loop parallel to one side or the other. Hitting F will flip which side. Hitting E again will revert to the default behaviour: interpolating between its original orientation, and whichever edge you are sliding towards.


Get Image Position in Image Editor for drawing lines with bgl

So I solved this, it appears that the image editor is also like a 3d coordinate system. So I followed a tut for 3D and then just changed the view to SpaceImageEditor and instead of drawing on 'POST_PIXEL' I drew to 'POST_VIEW'.
Code:

def __init__(self):
    self.draw_handle = None
    self.draw_event = None

    self.widgets = []

def invoke(self, context, event):

    self.create_batch()

    args = (self, context)
    self.register_handlers(args, context)

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

def register_handlers(self, args, context):
    self.draw_handle = bpy.types.SpaceImageEditor.draw_handler_add(self.draw_callback, args,'WINDOW', 'POST_VIEW')

    self.draw_event = context.window_manager.event_timer_add(0.1, window=context.window)

def unregister_handlers(self, context):
    context.window_manager.event_timer_remove(self.draw_event)

    bpy.types.SpaceImageEditor.draw_handler_remove(self.draw_handle, 'WINDOW')

    self.draw_handle = None
    self.draw_event = None

def modal(self, context, event):
    if context.area:
        context.area.tag_redraw()

    if event.type in {'ESC'}:
        self.unregister_handlers(context)
        return {'CANCELLED'}

    return {'PASS_THROUGH'}

def finish(self):
    self.unregister_handlers(context)
    return {'FINISHED'}

def create_batch(self):

    vertices = [(0, 0.5, 0), (1, 0.5, 0)]

    self.shader = gpu.shader.from_builtin('3D_UNIFORM_COLOR')
    self.batch = batch_for_shader(self.shader, 'LINE_STRIP', {'pos': vertices})

def draw_callback(self, op, context):

    self.shader.bind()
    self.shader.uniform_float('color', (1,0,0,1))
    self.batch.draw(self.shader)


Successful reconstruction can only be achieved with accurate tracking

Your error average should be under 1.0 pixels, preferably 0.3.

Issues with your file: Your tracking is not good...

Your trackers are too large, and have few distinct features. Don't track the center of a featureless object, try to track the edges that have contrast.
(read this post on camera tracking markers)

Select any of them and scroll throug the timeline to watch what the tracker is doing:

The shape you are tracking shouldn't be dancing like that.

It should be more like this:

Go through your trackers ONE BY ONE to fix them.

Instead of using only loc, try loc scale and change from keyframe to Previous frame.

Use the graphs and the dopesheet for the movie clip editor to determine which tracker have a high tracking error and get rid of them and re-track.

READ THIS POST to troubleshoot issues with motion tracking


How to have 2 windows display different modes in the 3D Viewport

Sure you can do that! I do it all the time.
When you drag out a new window, simply hold down Shift, at the same time, and that will tear that window away from the main interface! You can then move that new window to your other monitor and set it to what you like.
To change it to what you like, simply select this icon here:
Example


Yeah! That solved my problem, i downloaded the blender2.71.tar.gz2 version from blender.org and it have the cycles engine, though the tarball zip does not contain the installation. It have the self dependent blender package, just needed to be extracted. The site says the glibc2.11 is required, but my blender is working. i guess my os already have that. Thanx bro for helping me.


Everything looks great on camera, except when you turn on smooth shading

Your face is made of a huge ngon, if the ngon is not completely flat it tends to creates artifacts like the ones we see when you smooth, because of the stretched triangles that compose it. So you need to correct the topology and work with quads as much as possible, sometimes tris... ngons are ok if they don't cause any problem.
For iphones see answers here and here for example.


This is a common issue that will be resolved when overrides arrive in Blender.

However, a possible solution for your problem right now could be the following:
Drivers.

You can add drivers to the parameters in the node tree that you want to influence. E.g. attach the Factor of a Mix node to the x-Position of an Empty.
Make sure the Empty is in the same collection that you link.

Then, when you link the collection in a new blend file, you can create a proxy of the Empty and consequently use it to change the material.

I hope this helps point you to a working solution.


Video and audio strips of imported file out of sync?

You need to find out what framerate your footage is at. A video is saved at a constant framerate no matter how fast the game runs. Find out what that is, and in the Properties Window on the Render Tab (the settings on the right which is usually hidden on the Video Editor interface), set the framerate.

Then, in the Video Editor, drag your video in and find the end frame. Set the end frame to the ending frame of your video. (See this topic for help: How can I make my animation play for longer than 250 Frames? )

Also, set the player to A/V Sync (the button is right under the Timeline) so Blender will sync the audio and the video.


Ok, I figured it out.
When you HIDE an object and forget that you hid it... It will be there in your export laughing at you.  Don't be like me... remember your hidden objects.


Problem with return super().__getattribute__(attr) blender 2.8

Knowing one's self

You have called the following

emitter_update(self, context)

from the operator, where self is the operator instance passed as the self argument to the execute(self, context) method. Operators have no particle systems 8^). The update method expects self to be an Object type which has a particle settings attribute.

From within the operator use

emitter_update(context.object, context)


You can accomplish this effect using material nodes, a mesh, a spot lamp, and a camera.
Blend-File (made in UPBGE 0.2x)
https://blend-exchange.com/b/bOl2J557
Explanation
When the spot lamp's shadow, which is casted by the mesh, hits the surface of the building, the casted shadow will act as an alpha (transparency) mask for the building.
Screenshot (nodes setup)

Tutorial
https://youtu.be/4Seqm826oWk


Thank you for describing your question very clearly.
constraint is set to 1. Go to the frame where you want the constraint to be zero. Type zero on the constraint modifier, while you mouse hover on the number press "I" to INSERT a keyframe. Your number field will change color to yellow, thus effectively inserting a keyframe (0 zero) on that specific frame.
You are doing all right, just needed to set the keyframe to zero since all keyframes after the frame you need are set to 1.

If you find this is the answer, thank you for your consideration to vote me as the answer by clicking to the left :the icon with a check mark and upvote this answer.

BFCT_Schiller


I ran in to this problem. I was trying to simulate smoke in a sphere. I am using 2.83.
Eevee materials are not currently capable of rendering volumetrics other than the bounding box of an object. Look Under Volume Objects
If you are using cycles and having this problem then I believe how I fixed it was by selecting Is Planar under the Effector settings for the object that you want as the limit.


How can I rig mesh (from particle) on armature?

I got the answer.
They have multi user data. So they have set as like one object.

Unlink short Key = U 'make single user > object and data'


Ok 1 minute after posting I found the answer. I will answer my own question rather than delete in case others have the same issue as it is a easy one to miss.

Camera clip start set too high at .0001 now reset to .01 and all fine.

If admin want to delete my answer no worries. Thanks


How to select different bones while in weight paint mode?

Although the officially-suggested workflow is to select face mask by switching to Edit mode (since more powerful selection tools there), you can also quickly select faces or verts for masking In Weight Paint mode by toggling the two  buttons located on the headerbar, or simply press M or V to toggle them on/off.


What is the Python command to check if current view is in orthographic or perspective mode?

Region3D.view_perspective.

Get the space data of the 3D view area. A screen is split up into areas. The space associated with area is the active space.  The spaces 3d region has the view settings.

>>> for i, a in enumerate(C.screen.areas):
...     i, a.type
...
(0, 'PROPERTIES')
(1, 'CONSOLE')
(2, 'VIEW_3D')
(3, 'TEXT_EDITOR')

>>> space = C.screen.areas[2].spaces.active

If we are sure we are in a 3d view (a panel there, an operator that polls there) then instead use

space = context.space_data

the property to change is view_perspective, in example below I am in perspective view

>>> space.region_3d.view_perspective
'PERSP'

Tip A quick way to find the options available is crunch in something wrong.

>>> space.region_3d.view_perspective = 'FOO'
Traceback (most recent call last):
  File "<blender_console>", line 1, in <module>
TypeError: bpy_struct: item.attr = val: enum "FOO" not found in ('PERSP', 'ORTHO', 'CAMERA')

Check if in ortho view.  Could also check if in camera view, is camera ortho

>>> ortho_view = space.region_3d.view_perspective == 'ORTHO'

or perhaps (needs testing)

>>> ortho_view = not space.region_3d.is_perspective

Set to ortho

>>> space.region_3d.view_perspective = 'ORTHO'


How to do difference boolean between two objects in Blender?

Your problem is that the cylinders you use to boolean your cube have faces overlaying the cube faces, and the boolean doesn't work in these conditions. So here is what you need to do:

Select your 4 cylinders and join them with ctrlJ to make it simpler (one boolean instead of 4).
As you can see the top and bottom faces of the cylinders overlay with the horizontal faces of the cubes. To prevent this, just scale the cylinder object on the Z axis.
Now there is another overlaying, between some vertical faces of the cylinders and some vertical faces of the cube. So you need to select your cylinders object, go in Edit mode, then move each cylinder a bit away from their position on the X axis.
Now you can apply the Boolean, as you can see it works.


Is it possible to have a property sensor detect another property?

(I assume you want to compare on property's value with another property's value.)

No, the property sensor evaluates a single property only.

When you want to evaluate more properties you can use the expression controller:

property_1 < property_2

or the Python controller

import bge

controller = bge.logic.getCurrentController()
owner = controller.owner
if owner["property_1"] < owner["property_2"]:
    for actuator in controller.actuators:
        controller.activate(actuator)
else:
    for actuator in controller.actuators:
        controller.deactivate(actuator)

I hope this helps


Tutorials for blender 3d has an excellent tutorial over here

It uses renderToTexture with a mirrored UV map and a camera facing out of the mirror.
One thing to keep in mind is that this requires the scene to be rendered twice: once from the main camera, once from the mirror camera. As such, it can increase processor load quite a lot.


As per Mr. Zak's comment, I tried extruding edges instead of using edge loops + fill. After doing that I recalculated my normals (just to be safe), solidified, cleaned up any vertices that extruded too far, and repaired the STL in 3D Builder

I have sliced and printed the model successfully! Thank you!


How to restart the animation of a particle system?

I think you need (3) separate Particle settings for that, like so:

Also a gif:


Rigidbody container is spilling out contained rigidbodies

Within the Scene properties are the Rigid Body World settings. This includes a Steps Per Second property. This setting determines how often blender should check the position of objects in the scene for how they should interact - faster moving objects require a larger number of steps to prevent them passing through each other before Blender detects the collision.


How to bypass OpenGL 1.2 requirement for remote GPU rendering?

The problem is that the Remote Desktop Protocol (RDP) does not allow for OpenGL, a workaround is using an app like TurboVNC. I've been able to render in headless machines that way with no issues.


Create a Glow Layer

You separate your render into two, the normal render and a glow render, both layers with a transparent background, in the glow layer set all the objects to have the same material (use an emission shader with the color of the glow you want):

Then, you can use this Node Setup in the Compositor:

You have to take into account that, in this example, the lighting is lame, that's why the effect doesn't look realistic, but using the same lighting that your scene will give you great results


Faces distorted when rendered and 3D View in Rendermode does not work in Default Layout

I couldnt solve my second Problem, but this is only a minor one.

The answer to the First.

I had an Hemispheric Light in Blender Render. When i turned this off there was no problem anymore. I am Using this figure for Unity, an there was no Problem at all.


Blender ruins model/animation when switching actions

It's not a bug, for the action called TestAction.001 you can see that a LocRotScale track has been created, it means that, additionally to the keyframes you've created for the bones, you've created some keyframes for the whole armature in Object mode. And if you unfold this track you'll see that you have Scale keyframes as well as Location and Rotation keyframes. So delete the whole track, then, as it has changed the size of your armature when you've selected it in the Dopesheet, just select the armature and altS to reset the scale.


How to reset the axis of mesh rotated in edit mode?

You may Snap Faces in object mode which can cause a rotation.

You may create an Orientation. And Transform the orientation.

https://www.youtube.com/watch?v=Gc8BekthXAQ

There are also add-ons. You will still have to do some work. Probably scripts exist as well.  I can make no statements about 2.8.

Once the axis is reset, you need to select two faces source and destination.  Then you have the freedom to select location in the orientation and rotation along z-axis of local transform orientation.  The requirement of artistic/technical freedom requires some small amount of work from the Blender User.

You can make changes in edit mode, then go to object mode, then enter edit mode and undo those changes with the typical keystrokes of Control-Z.  I suggest you test it because I would use that feature rarely.  I would not perform hundreds of useful things and then undo in edit mode.


How to use a negative driver value when scaling?

Instead of using a Transform Channel, consider using a Single Property when you need to get the exact value of some property:


How to duplicate an object hierachy and keep the copies in sync?

Using Blender's "Linked Libraries" feature may work for you here. It lets you import and link groups or objects from another .blend file  using File > Link, then selecting a .blend file with your table (and chairs).

This way, you build your table and chairs in another file, then use them however you want in your main scene. Editing the table file and reloading your main file will update with your changes.

Another option (which I think also works with a linked file) is to group your table (and chairs), then choose Add > Group Instance to create an empty that will duplicate the grouped objects. This is called a DupliGroup. Changes you make to the   grouped objects are updated to all dupligroups.

If you need a lot of these objects, you can also take a look at DupliVerts.

Relevant Documentation:
Linked Libraries
DupliGroup


How to use baked fluid with network render?

Yes, but all the networked machines will need access to the cache.

Another way to do a network render:

All machines need access to the blendfile and any external data (textures, fluid sim caches, etc.)
Make all the machines output the rendered images to a shared directory
Disable Overwrite in Render Settings > Output for all machines.
The Overwrite option will overwrite existing image files in the output directory. Disabling it causes blender to skip rendering the frame if a corresponding file already exists.
Enable Placeholders in Render settings > Output for all machines.
When rendering is started on a new frame, if the Placeholders option is enabled, blender will create an empty file where the final output image will be written after the render is complete.

Then:

Open the blendfile on the first machine and start the render
Open the blendfile on the second machine and start the render

Each machine will output images to the shared output directory and skip already rendered frames because Overwrite is disabled.

Placeholders is enabled so that machines will skip rendering frames that other machines are working on at the same time.


mapping geometric shapes on surfaces with little distortion

I would use the UV Project modifier.

On the backdrop object just add the modifier.  You need to fill out three things (and make sure to check the Override Image option).

The image
The uv map (does not have to be a pretty UV map, you just need the slot)
The projector object. If you use a camera or a spot light as the projector the Scale values will control the size of the texture. For any other type of object they do nothing, the object scale controls the size.

The node to render this are the same as you would use for any image. The modifier is changing the UV map so the image gets rendered "projected."

It works really well (identically to how building projection works) which means you also get the real life "problems," off angle viewing will break the illusion. Also the focal length of the camera makes a difference (it will look perfect with an orthographic camera.)


why is my object solve not matching my plane track?

Tracking a piece of paper as it moves around in a video is a matter of following some points on the video, an image can then be distorted relatively easy to match the movement of the plane.

To track camera movement you need points that are not only following points on the video but that can also be used to define a three dimensional box in front of the camera. When reconstructing camera motion you specify some points that are flat on the ground and also raised up on a wall. This provides a way to re-create the camera movement relative to the given points.

Once you have the camera movement you can then track objects that move relative to these points.

With enough points on an object you can get the same effect as an object moving in front of the camera, but in your example video you have nothing that adds height to the sheet so there is no way of re-creating the rotation of the page, the best you can do is distort a 2d image to match the distortion of the page in front of the camera.

In your screenshot you have a solve error of 18.65. A solve error less than 1.0 is considered a good track with values up to 3.0 considered possibly good enough to work with. Anything higher than 3.0 is considered a bad track.


Setting Up A Minimal Sculpting Environment With An Image Area

Ok, here we go:
1. Remove UV Screen
This may sound contradictory, but necessary to remove the timeline. Blender is weird like this and will only collapse a section if their is only one section spanning the width of it above it. Remember to collapse a section pull on those little three lines in the top corner

2. Collapse Timeline
Pull on the three corners in the 3d view as shown in the image.

3.Right Panel
Remember step one when we collapsed the UV screen to collapse the timeline? Well we have to do this again to collapse the right panel. First pull down then up as depicted in the image below to remove the outliner.

4.Finishing up
Now, press T to close the tool panel. Next pull the top three corners of the 3d view toward the right panel to collapse it. To remove that top bar pull on the three lines below the info icon and pull down, then up. Finally, Pull the 3d view corner again to the left to open up another 3d view. You can change it to UV image editor by clicking the icon.

Further Reading
How to close view windows?
Arranging Areas - Blender Reference Manual
Simple, Nice Explanation On BSE
Great Youtube Video


I'd like to move the 3D Viewport back to its starting position

You can click the + at the top of the window and create a new Layout Workspace.


You can use a mix of both renderers to get a mask. The Cycles scene would be super extra low fi to give you a fast render, and then you grab the Vector and the Depth from it and use it on the Composite screen to mix with your new Eevee render.
Here is one example of how to do it:
http://blenderboydiaries.blogspot.com/2019/01/how-to-get-motion-vector-blur-in_17.html


The node editor window has three basic options:

The nodes you need are in the  compositing mode.

There is no need to switch to cycles to access the compositor.

Please read: https://docs.blender.org/manual/en/dev/editors/node_editor/


Try this way:

Select both sides, W - Bridge Edge Loops. Enable Merge, set Factor to 0 (or 1);
Keep current selection, V to rip, then RMB;
Mesh > Edges > Edge Slide ( or GG) to enable Edge Slide. E to toggle Even, if the current result is in a wrong way, then F to flip it (those are options shown on 3D View header).
Move to the expected position, then LMB or Enter to apply changes.

P.S.: For the 3rd step, you can simply CtrlB to bevel those edges. However, the normals for both islands are opposite in your case, you need to unify them before that.


Why Is the cloth simulation on my model turning into spikes?

I can't fully tell but...did you bake the cloth physics, and then edit your mesh? If you edit the mesh after a bake, a lot of the times it will end up like this, especially if you edit pinned vertices. Remove the physics, make your edits, and then reapply the cloth physics.


You disabled Display overlays.

To enable Overlays you can use Alt-Shift-Z by default.


Translation is stuck in increments, how do I set back to free movement?

You enabled snap. You can disable it with this small magnet button:


I have a project with multiple video files that I want to pack for a render farm how should I do this?

Blender doesn't pack videos nor image sequences. If you want that to be possible in the future, you can upvote this rightclickselect proposal I made. But know that it has little chance to happen.

However, Sheep it supports .zip files and linked datablocks. So I'm pretty confident videos should work this way.
Zacharias Reinhardt explains how to use linked assets with Sheep it in this tutorial (link goes to the appropriate timecode).


Body and Armature A-Pose / Clothes T-Pose

The goal can be reached having all 3 objects (Armature, body and armor) in a T-pose as Rest Pose.

This can be a procedure:

Move in pose mode the armature using FK (while it is deforming the body only) until you get the desired T-Pose; then adjust the IK controls so that there is nearly no difference between IK and FK.

Select the body and Apply its Armature modifier.

Select the armature, turn on all its bone layers, select all bones and click "Apply pose as rest pose" from the menu "Pose - Apply".

At this point you can parent the armor to the Armature, add a new Armature modifier to the body and set  the Armature as object.

Don't forget to move the new Armature modifier on top of the modifiers stack, and check its "Mantain volume" option.

This procedure doesn't affect any premade weight assignements.


How to import many images so assign to texture_node and duplicate "n" times objects and materials?

You could use the import images as planes add-on from preferences->add-ons to quickly import your 244 photos as a plane with matching dimensions. The add-on lets you set basic material options for cycles and bi on import.
The created planes and materials get the same name as the image. After import, you would just need to place the planes on the correct locations in your scene.


Rigid Body Issues (Chain is passing through object and not following the mesh)

This example uses the same arrangement mentioned in my comments above in that the falling object is parented to another which is to drag it along (or down) with it.   It's been done in Vers 2.77a. (Blend file below)

With this one, a necklace wouldn't be rigid when it lands, so it's best to keep the array and curve modifier's active so both can be adjusted to emulate real world physics. i.e. deform the necklace's curve.
Soft-body physics etc. can be tried but for this sort of job emulating physics with a few simple keyframes and hooks is arguably more effective and efficient.
To begin with, a circle curve in Edit mode has just 4 control points.  Intermediate CP's can be added by selecting two adjacent points and using "Subdivide". (press W)  Reshape the necklace as necessary at frame 1.
Six CP's are used here.  Nth, East, Sth & West, with two subdivides, SE & SW.
If it's going to be noticed, the chain's array modifier's link offset-value, will need minute adjustment via a keyframe when the array comes to rest.  This will prevent an overlapping link appearing at the array's original starting link.
Animate the hooks to deform the curve-circle and emulate physics.  The Graph editor makes this a relatively simple task, reshaping each hook's curves accordingly.  (See the Blend file -> Graph Editor)
-============-
The large circle-empty designated "Nav" (navigation), parents everything involved with the necklace. i.e. the original array, the curve circle, and hooks, to keep it all together.  The 'Nav' in turn is parented to the bust.
It's the Nav-empty that's keyframed to take the whole thing down initially, and on impact the hooks take over to deform the necklace's curve-modifier.  The bust when moved, takes the whole thing with it.
You would do the same thing when the bust (or character) is moving about, simply deform the necklace's curve to suit and emulate physics once more.
If you're looking to the physics engine to do it all for you as a game engine might, I'm not sure that would be practical in Blender.


Fixing unclean Normal map on round shapes?

The only way to improve the look here is to increase the low-poly polycount.

The normal map looks ok, but if you will face any problems in the future, you can find a massive amounts of good info here: http://wiki.polycount.com/wiki/Normal_map


Creating transparent glass with an image texture w/ alpha channel

I found a solution to your problem. The answer lays within the lightpaths. You want your direct rays with your texture and alpha and your indirect (Colored shadows) using a solid blue object. This can be done fairly easy inside the nodes.
So, this shadow:
With this texture:
This is your solution:
One material will be used when rendering the cube and the other one when rendering the shadow. The Lightpath node will output white when the ray is directly coming from the object to the camera. Black if it isn't.


How do I extrude a face to a single vertex

One way is to use Vertices > Merge (or Alt+M) > Collapse to turn multiple selected faces into multiple vertices:

Collapse
Every island of selected vertices (connected by selected edges) will merge on its own median center, leaving one vertex per island.

Merging vertices


Can someone help me understand how this was done with the armature?

I try to understand your problem. If you're talking about, let say, the left index finger controller, you can see on the N panel that its location and the X and Z scales are locked: Actually he uses both Y SCALE and ROTATION to make the finger bend, so its movement completely depend on these constraints. If you want this finger to do something else you need to free it from these constraints on the particular frame, or all along the timeline. I personally find it a bit complicated but maybe he has good reasons to rig this way.


Animation Nodes only wants you to remove other version of Animation Nodes currently installed. So just uninstall/remove any other version of Animation Nodes before installing it. So, leave those addons as is.


The character is posed: the bones of its armature are not in rest pose (at least one of them). When you enter edit mode, the mesh is shown in its rest pose.

You can enable these two buttons to have your armature have effect in edit mode also:

Or you can temporarily disable the armature modifier to show both meshes in rest pose, or even select all bones and press Alt + G , Alt + R, Alt + S to reset all poses of the bones or, at last, select the armature and in its properties panel choose rest position instead of pose position.


You can simply use the Mirror modifier.

Object Mode: Select the flaps.
In the Properties panel, click the wrench icon.  Add Modifier, Mirror.

At the bottom, Mirror Object: select your plane object.

Axis will depend upon orientation of scene.
I believe X is the correct orientation in your image.

click Apply, and you're set.


All of the cycles material nodes available in blender have OSL script versions that are used when OSL is enabled. These scripts can be a good place to begin when you want to start your own OSL script. You can view them online at developer.blender.org or download a copy of blender's source code to view locally.

For your example let's start with the toon shader. The main part is the call to diffuse_toon(). For IOR the glass shader by default calls microfacet_beckmann_refraction() with some other calculations. Merging these two together you could start with an OSL script as -

#include "stdosl.h"
#include "node_fresnel.h"

shader toon_with_IOR(
    color ToonColor = color(0.0,0.0,0.8),
    float Size = 0.5,
    float Smooth = 0.0,
    color GlassColor = 0.8,
    float IOR = 1.52,
    float IOR_Roughness = 0.0,
    normal Normal = N,
    output closure color BSDF = 0)
{
    float f = max(IOR, 1e-5);
    float eta = backfacing() ? 1.0 / f : f;
    float cosi = dot(I, Normal);
    float Fr = fresnel_dielectric_cos(cosi, eta);

    closure color ToonPart = ToonColor * diffuse_toon(Normal, Size, Smooth);
    closure color GlassPart = GlassColor * (Fr * microfacet_beckmann(Normal, IOR_Roughness) +
            (1.0 - Fr) * microfacet_beckmann_refraction(Normal, IOR_Roughness, eta));

    BSDF = ToonPart + GlassPart;
}

Instead of adding the two results you could mix them together, you would then add another float input called Fac and change the last line to BSDF = (1.0 - Fac) * ToonPart + Fac * GlassPart; - that's from the mix closure node.

At this stage you can easily test the result by comparing it to the nodes we got the code from. Then you can go further and customise the result to get the result you want.


Go to sculpting remesh is on top or right bar depending on tool aligment. remember to use adaptation this one is useful where you have lot of flats check out quads too


Why can't I move the camera as freely as I can navigate in the 3D View?

The camera has absolutely no restrictions whatsoever. Normally you can move it just like you can move any object with your Move, Rotate and Scale tools.

If you want something like a first-person-mode expand the side panel on the right edge of your 3D-view (or hit the N-key on your keyboard) and then go to the tab View->View Lock and toggle Lock Camera to View. This will "bind" the camera to your viewport perspective.

Once you're happy with your camera position un-toggle the option to move freely again, without accidentally displacing your camera.


Is it possible to add key frames to initial shape setting?

Not as keyframes, but you can create presets when you add a shape, by pressing the + sign right next to the operator presets.

By creating a preset you can recall custom settings.

Note that once you modify an object in any way there is no way to go back and re-edit the parameters of the created object.

Read: Is there any way to edit parameters for an object after it is created?

If you want to create an animation by modifying the shape look into using shapekeys

https://docs.blender.org/manual/en/latest/animation/shape_keys/index.html


Subdivide doesn't work on face after subdividing and smoothing vertex on another face of mesh

As Mr Zak says above in comments, face with more than 4 verts often give troubles editing, like here. It is usually better to avoid ngons and stick to "quad" face (4 verts. 3 verts is also bad for animation).

But, if you wish, you could edit your mesh first to make the side face a quad face, using knife tool: in ortho side mode, use K, followed by C - to cut straight lines - and Z to cut through all mesh.

Then click to start the cut,

click to end the cut

and press enter to confirm. You get this.

This allows you to to create a loop (since normal face loop tools won't work either, for the same reason as subdivide):

the side face is now a "quad" and subdivide works:


Here's how I got it to work:

1) Upgrade to the latest Blender 2.8.1

2) Go to export panel:

Export -> glTF -> Presets

3) Set the options:

Transform -> +Y Up
Animations -> Always sample animations

4) Test your exported animation in a viewer:

https://gltf-viewer.donmccurdy.com/


How do you keep blender from shutting down?

If Blender crashes, it's a bug in Blender (or you're doing really crazy things, but let's not assume that). Please help us Blender developers to fix this bug.

Investigate how you can make Blender crash as fast as possible, and as reliably as possible.
Think of a way to describe the bug you just found.
Search for the bug, to see if someone else already reported it.
If it hasn't been reported yet, report your bug. Be sure to include an example blend file and the steps required for the developer to make Blender crash.

Especially this last step is important. If the developers can reliably make Blender crash the way you made it crash, it will help tremendously in getting things fixed.


Interface. Join areas is not working properly

Just right click on the border and select Join Areas.
Then you can choose which way to merge them.


Vertex Weights:
You can use Vertex Groups.

Subdivide your plane (W> Subdivide)

Deselect the middle with Circle select (C) and use MMB to deselect (or hold Shift and use LMB)

Add a vertex group and click Assign in Properties > Object data > Vertex Groups:

Select the vertex group in Properties > Particles > Vertex Groups:

Textures:
You can also use a Particle Texture. This does not require that you subdivide your mesh.

Add a particle texture to your object by clicking New in Properties > Particle system > Textures. Then switch to the texture tab.

Ensure that the the datablock type is set to Particle system.

Set the texture type to Blend

Set the Progression to Sphere

Enable Density in the Influence section so the texture influences the density of the particles.

Enable Ramp to control the texture with a color ramp.

Flip the ramp and adjust the stops so the particles are correctly placed.


You can use the solidify modifier to essentially add a second copy of the object on the inside. Select the inside geometry and assign it to one material, and the outside geometry to another material. Then they can be textured differently!


Can you reduce detail with a normal/bump map?

In the case of a spherical object, it is pretty simple. Just add a Normal Edit modifier and enable Auto Smooth in the Normals panel of the Object Data menu.

Before:

After:


Blender Orient an object (displaying Vector Arrows)

Consider a [Track To] constraint  which will rotate the arrow toward the location of a given target.  The green arrow points to the red ball below, wherever the ball happens to be.

In the animation below we see a few alternatives with constraints and modifiers

The blue arrow is a curve in case you find the straight lines excessively boring.  Circular cross section bevel. The curves has hook modifiers for the end points.  A third point is added into the blender curve to introduce more [visual curve] into the blender curve. The visual curve is optional. The green cap is position with a [follow path] constraint.  Of course this flexibility requires more work.
The yellow arrow is an array modifier fit to curve straight line
The large green arrow is the [track to] constraint as before
The hook constraints


operator_enum of object.mesh_add and object.empty_add is displayed unexpected

I've found the solution:

The API has been changed (Code from /usr/share/blender/scripts/startup/bl_ui/space_view3d.py):

class INFO_MT_mesh_add(Menu):
    bl_idname = "INFO_MT_mesh_add"
    bl_label = "Mesh"

    def draw(self, context):
        from .space_view3d_toolbar import VIEW3D_PT_tools_add_object

        layout = self.layout

        layout.operator_context = 'INVOKE_REGION_WIN'

        VIEW3D_PT_tools_add_object.draw_add_mesh(layout)

I was misleaded by this comment in INFO_MT_add:

#layout.operator_menu_enum("object.mesh_add", "type", text="Mesh", icon='OUTLINER_OB_MESH')

This code doesn't work anymore!


Can mining rig be used for blender rendering?

I went out and purchased a P106-90 video card for about $70.
The card showed up properly on windows 10 and automatically installed the drivers.

Blender automatically detected the card

And it cut renders down from
1:32 to 49 seconds
Which means I was able to cut my render times in half.

Additionally, searching the blender benchmark data shows benchmarks from users with the cards p106-90 and p106-100
https://opendata.blender.org/benchmarks/query/?device_name=P106-090&device_type=CUDA
Note: According to some sources, the eevee render only uses the first gpu, so its likely adding a second gpu won't increase the speed of previews. Only Cycles renderer is able to use multiple GPUs.
Also these cards can only be leveraged for blender, since nvidia blocks the ability to use these cards for video games.
Additional information

Motherboard: ECS A885GM-A2
Windows 10 Home


Is it possible to hide particle emitters in the viewport without hiding particles?

Another way (similar to Michal's answer) is to use a Mask modifier:

Add an empty vertex group to the particle emitter by pressing the + button in Object Data > Vertex Groups:

Add a mask modifier after the particle system with the empty vertex group:

There was a bug in 2.69; in order for the mask modifier to work you had to assign and remove some geometry to the vertex group. It has since been fixed.


Optimal noise threshold for Adaptive Sampling with AI Denoiser

"Optimal value" is quite a subjective measure and depends on available render time compared to desired quality - so it's not possible to generalise to one specific "optimal" value. The impact will also vary based on your particular scene and lighting conditions.
For each 'tile' rendered in the final result, Blender determines the 'noise' for each sample over the whole tile - with the noise being measured by comparing each render result with that of the pixel it is being merged into. As the tile converges towards its 'ideal' (infinite samples) pixels the difference between the newly rendered "passes" and the current rendered result (the combination of all the previous "passes") will reduce. The Noise Threshold determines how close the difference should be before this tile is considered 'complete'. The noise will depend on the amount of illumination and bright/dark sharp edges as well as reflections and caustics, etc.
The "optimal" setting is subjective as well as the render overhead giving diminishing returns (doubling the samples will typically half the noise - so to get rid of all noise requires a very large number of samples). The best option is to render a scene at various thresholds and compare the result with the render time, picking the level with most appropriate render time to quality ratio.
NOTE: The adaptive rendering will only make use of the maximum number of samples you are rendering your scene with. Therefore, ensure your total Samples is sufficiently high to allow the adaptive sampling to get the noise level low enough to produce the desired quality for a 'full' render.
In order to determine an optimal value for your scene you could follow the following process :

Increase the total number of render samples to a suitably high value (the 'best' quality you desire for your render)
Set Threshold to a suitably high number so that each tile is effectively only rendered once. eg, 1.0000.
Render the scene and record the time taken.
Reduce the threshold to a significantly new value - eg, 0.1000.
Render the scene and record the time taken.
Compare the result and time taken.
Repeat until you see suitably high quality results. eg, at 0.001
Try increasing slightly again (eg, 0.0025) to compare the time saving with additional samples until you hit upon the 'sweet spot' for your situation.

Bear in mind that like the Denoiser, Adaptive Sampling is not a 'magic bullet'. It requires some tweaking to get the best results and will always be a trade-off between render times and final render quality - which will depend on your scene and your needs and priorities.


does Blender have a Material Swatches panel showing all available materials?

It does, in the materials tab, and the arrow points to the droplist of all your materials. I never tried drag'n'drop, though, so you need to check it. This is from Blender 2.7x so the current version (2.9x) must have this much or more.


Your Curve Segments are highly twisted. To correct this you can use Twisting > Smooth under Curve Data tab - Shape section.


Trying to reduce polygons (decimate) is not an option

You'll probabably have to do retopology and then bake the normal information into the low poly one, in case you don't know what I'm talking just google "Bake in blender high poly to low poly" or something of the sort and you'll find plenty of tutorials on how to do it
Also you could always do this too: Youtube link


Create a plane for your image to be on. put the image on it with (with alpha transparency). In particle system settings under "render" chose Render as "Object". select your plane.
Made you this quick video
EDIT:Image as smoke
shoudl work now


After @Xylvier's suggestion (thanks!) I wrote in the Kit-Ops support page and the developer explained to me that it is a function within the plug-in which can be turned of.
I suppose there is a recursive function which selects all the elements which are recognized as part of the main container object.


BVHTree.FromPolygons not accepting vertex list

Oops, it wasn't the verts that was the problem. It was the polygons sequence. It requires a sequence of sequences:

BVHTree.FromPolygons( verts2, [ (0,1,2,3) ] )

Thanks lemon for the answer!


Multi-File Packages need to unregister all classes from files

If there are any custom PropertyGroup classes in the submodules, they have to be loaded in the correct order. You also need to "unregister" the submodules.

This is a pattern in the main file

def register():
    #register operators and propertyGroups explicitly
    bpy.utils.register_class(myPGClass1)
    #and/or run a helper function that finds all the classes and registers them

    bpy.utils.register_module(__name__)

    #add to the schema
    bpy.types.Scene.myTool = bpy.props.PointProperty(type=myPGClass1)

def unregister():

    #important: delete custom schema
    del bpy.types.Scene.myTool
    #unregister_classes, or use helper
    bpy.utils.unregister_class(myPGClass1)
    bpy.utils.unregister_module(__name__)

if __name__ == '__main__':
    register()

The this should work find if everything is in the __init__.py file. But since this is not the case, then these are the issues I discovered.

register_module() just finds the bpy.types.* classes in the module and runs register_class which looks to be a python call into C. So this doesn't look in the other files. So one has to call register_class on anything defined there.
enabling and disabling scripts will find the register and unregister functions by duck-typing. But only the __init__.py file will be in the list that gets checked. So anything in unregister() will not get called. This is the del types.myType line.
even though registering and unregistering is not working. Reloading will import the submodules, thus causing erratic behavior and classes will be reregistering, and the schema will try to update from a dereferenced raw pointer.
disabling/enabling addons has more to do with marking modules with a flag than with loading and unloading modules. Loading happens on first load and reload(f8).


Two keyframes will suffice, if the centers of the objects are already spread out in the correct order.

Check the manipulate center points button.

⇧ Shift RMB select the objects.
Press I and choose Location to keyframe the location.
Move the cursor in the timeline to the second position. I have the dopesheet open to see the created keyframes.
Press S to scale the objects. Because of the Manipulate Center Points only button, the objects will only be moved, but not scaled. You can constrain the movent to a specific axis, by pressing S>X, S>Y or S>Z.
Repeat 3 to insert a second keyframe.


Bone Weights for Mesh are not behaving as I expected

Choose the Parent Armature Deform best suited to you.

Check your modifier panel settings.  Know that your bones in your example and mine are perpendicular to the rather linear mesh portion example. For limb animation and rotation for organic models the bone is often inside the mesh for major limbs.  Consider making the bones parallel to the mesh.  Consider blurring the weights for gradual transitions.

Try these settings above when you parent the mesh to the armature.

You will achieve a more flowing gradient.

[With Automatic Weights]
Try the other settings.

You will achieve a more abrupt gradient.

[With Envelope Weights]

Below Closeup Abrupt Influence with a little curve.

Below Closeup Flowing Influence with a big curve.

Another way to get abrupt influence in my example is to choose Bone Envelopes only in the modifier panel.


Can't scrub through animation in Blender 2.8

Resolved:
Preferences > Keymap > Animation > Change Frame

Default value: shift right mouse

Change to: Left mouse

Note: No need to disable the "box selection" behavior. This overrides that. The above change is all you need to do.


Can we create an Action from a Dopesheet animation?

Actions are automatically created the first time an object receives a keyframe of any kind. That is, assuming an action has not already been created in advance for the purpose of animating said object. So there would not be a reason to create an action for a Dope Sheet animation, because one would already exist as soon as there was an animation. This connection could be made clearer through the Blender UI, granted, so I'm not surprised to see that people are often unclear about exactly when, or how, actions come into being.


You could try to use "limited Dissolve"
Just select all the vertices, then press X > Limited Dissolve, after that try the inset again.


you can stabilize with tracking you're video in blender.  Here is a youtube tutorial for that:https://www.youtube.com/watch?v=nU8zqn091rM


Python Opengl Render doesn't show texture

If you can render from the GUI button I assume that you have the method to display/shade objects in the 3D view set to Texture.

With that out of the way the only thing that you need to do is to set both the write_still and view_context to True like this:

bpy.ops.render.opengl(animation=False, write_still=True, view_context=True)

If you only set one of them to True you get the solid display


ctrl+., then scale as usual.

This is basically this option:


How to make blender render a further distance

Increase the End Clipping of the camera in it's Lens properties.


Why can't I get the foot and the ankle move with the rest of the leg?

The main problem is that you are setting lots of IK constraints. To fix this I disabled the IK constraints for all bones except for the leg.lower_L.001 bone. To disable the IK you click on the eye icon as shown below:

Then I select the leg.lower_L.001 bone and set the chain length of its IK constraint to 3 to affect the whole leg (it's 3 parents) and now the IK works great as shown below:

To move the bones in edit mode, you will need to select the whole bones and move them together as shown:


You could give your robot armature a Child Of constraint and choose the root bone as parent, don't forget to click the constraint Set Inverse button so that the armature stays where it was.


bisect plane normal (mesh and bmesh) how calc the 3th vector to mathutils.geometry?

The plane normal is the Cross Product of two vectors laying on that plane

  N = normalize( Vect(P1,P2) X Vect(P1, P3) )

where Pn is point on the plane
all these calculation are done using the mathutils.geometry.normal(vectors) which takes 3 points and return the normal vector

Note: Normal direction depends on the Points order

Update

to get the third Point we use the function region_2d_to_vector_3d() which take a 2d coordinates and returns the a normalized vector of the view at this point ,then we add this vector to the point which we used its 2d coordinates to get a new one on the same line of sight (same plane ) , at last we pass the three points to the normal()

v3 =  view3d_utils.region_2d_to_vector_3d(viewport, area.spaces[0].region_3d, co_2d)
v3 = v3+ vert[1].co

normal =  mathutils.geometry.normal(vert[0].co,vert[1].co,v3)

Note you have to pass the the co_2d not co_2d_w to the bisect()

the file


Get the selected median point in python?

You can calculate it quite easy:

import bpy
from mathutils import Vector

ob = bpy.context.object
ob.update_from_editmode()

me = ob.data
verts_sel = [v.co for v in me.vertices if v.select]

pivot = sum(verts_sel, Vector()) / len(verts_sel)

print("Local:", pivot)
print("Global:", ob.matrix_world * pivot)

You could also use the bmesh module, but the standard API appears to be faster despite the update operation:

import bpy
import bmesh
from mathutils import Vector

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

bm = bmesh.from_edit_mesh(me)
verts_sel = [v.co for v in bm.verts if v.select]

pivot = sum(verts_sel, Vector()) / len(verts_sel)

print("Local:", pivot)
print("Global:", ob.matrix_world * pivot)


How to render as only wireframe in Cycles?

Add the Wireframe modifier and adjust the Thickness value.

Now set up the World's color to black and make the wire look brighter (replace Diffuse with an Emission shader). You may also increase its Strenght value to 2.000 or 3.000 if it isn't bright enough.

To vary between the smooth wireframe object and the polygonal wireframe object place the Subdivision Surface modifier above the Wireframe modifier and set up the desired amount of subdivisions. Now changing the type from Catmull-Clark to Simple will result in making the wire look more polygonal.

Here's the rendered result.


Apart from the article you linked to, rag doll physics refers to the ability of a character in a video game or simulation to be able to react to falling over or being hit in a more dynamic way.

Rather than having to create specific animations for falling you could let the character fall and determine how it moves based on how it's limbs collide with each other or the ground and how they drag each other (as long as a correct hierarchical skeleton is present) when a force is applied.

These are calculated on-the-fly in the game engine when the game is run rather than having been predefined beforehand (though they could have been limited to only have a certain amount of effect or be set to mix with a key framed animation).

The addon appears to help with the setting up of the collision boxes and game logic for the limbs that are necessary for accurate collisions.

The term rag doll is used because as the character or object falls it may have the appearance of a doll as it loses stiffness and collapses.


As the name implies the Maximum operations picks the maximum of the two input values, meaning it chooses the greatest of the two.

In your case by calculating the maximum between $10$ and $76.3$ you obtain a resulting intensity value of the highest input, hence  $76.3$.

From what what you describe you seem to want the opposite operation. If you set it to Minimum it will pick the smallest value of the two, effectively limiting emission to $10$, or whichever value is lowest.


Modeling a car wheel arc: Move vertex to form an arc

There are two tools that can help you achieve that.

1) Scale to sphere (Alt + Shift + S)

2) LoopTools Addon to space out vertices.

I recommend you proceed like this:

Scale to sphere

Set the 3D cursor to the center of your arc. We will use it as the pivot point for scaling the vertices.
press "." (NOT on the NumPad) to set the pivot point to the 3D cursor
select all the vertices you want to sit on the arc.
press Alt + Shift + S and move your mouse until the vertices align on an arc.

Space the vertices

Enable the LoopTools Addon in the User Preferences
with the vertices selected, press W and select LoopTools - Space


How to render with same style as seen in solid viewport?

Change the render engine from Cycles or Eevee to Workbench in the Render Properties tab and play with the configurations:

also, this video show in details how to use Workbench:
Introduction to Workbench Blender 2.8


readline is a blocking operation : http://pyserial.readthedocs.io/en/latest/shortintro.html#readline

Try to use something like :

def modal(self, context, event):
    if event.type  == 'LEFTMOUSE':
        ser.close()
        return {'FINISHED'}
    if ser.inWaiting()!=0: # or if ser.in_waiting !=0: (see remarks below)
        self.x = int(ser.readline())
        if self.x >0:
            value = int(self.x)
            value += 10
            degree = value * 3.14/180
            bpy.context.object.rotation_euler[0] = degree
            print(degree)
    return {'RUNNING_MODAL'}

Another edit as I have read that "inWaiting" function may have been changed into a property form from v3.0 of Python :

  in_waiting
      Getter:   Get the number of bytes in the input buffer
      Type: int

Return the number of bytes in the receive buffer.

Changed in version 3.0: changed to property from inWaiting()

So you should replace "if ser.inWaiting()!=0:" by "if ser.in_waiting !=0:".

Edit for a little explanation : the line "if ser.inWaiting()!=0:" wont block as it is just testing if there is something to read. So if nothing is available, the function will directly go through the "return {'RUNNING_MODAL'}" without blocking.

You can also test the behavior, replacing "if ser.inWaiting()!=0:" by "while ser.inWaiting()!=0:". It's hard to know which is better. The difference is "if" will immediately give the hand to Blender and "while" will eventually take into account several serial inputs before giving back the hand to Blender.

For this line :             self.x = int(ser.readline())
You should also read data depending on the waiting available bytes you need here (but as I dont know how your device communicates... I cant say).

(not tested)


This feature was added to Blender in version 2.75a.

To enable it, you have to be in Camera View, which you can enable by pressing Numpad 0. Optionally, you can lock the camera to your view by pressing selecting View > Lock Camera to View in the panel on the right-hand side of the 3D View (N).

To enable the Anaglyphic viewport, go to the Render Layers tab of the Properties panel, and check the Views checkbox. The default settings should be sufficient:

This is what it looks like:

For more detailed information, check out the relevant Blender Manual page.


Branched Path Tracing control for preview in 2.78

With branched path tracing the viewport preview quality is controlled by the AA Samples setting, to the left of the sample settings.

The amount of bounces is multiplied by the number of Anti Aliasing samples, thus controlling preview quality while keeping the same settings in sync for final render.

If those are not enough for you, you can alternatively add some custom presets on the menu above, keeping a lighter one for viewport preview, and a more complex one for final production.


How to do basic parametric modeling onto a spline

Starting from this thread (Make a 3D tube with a bezier curve), I figured that the curve modifier had to be used somewhere. First the spline and the length however.

Use  the following spline settings:

For the length of your object, you can use the array modifier with "Fit Type" set to 'Fit Curve' and then select the curve you want to trace. Then pick your start & end cap. Next up append the curve modifier and take the beziercurve as the object. (deformation Axis = x)

Lastly figure out how to reposition your endcaps so the vertices close up. (I haven't fully grasped the math behind this myself).

EDIT: Considering the end caps. Turns out the array matches them perfectly when you just 'snap attach' them in edit mode to the middle section that you want to array. As in the picture below.


How to quickly fix (or avoid) the n-gons caused by boolean operation?

Select the N-gons with Shift+G
CTRL+T
Alt+J

This is the fast and easy way. The minus is that it's not always all quads. And avoid Boolean if you can as corrections are required if you use it

OR, easier yet

Use CTRL+R once on the pointed edge and snap it to vertices before you OK it.

Btw. okaying answers gives you +2 reputation.


With cycles, how do I render only highlights and only shadows and nothing else?

I'm not exactly sure about what features you need to highlight, and you might not like my solution because it will just tell "global" highlights from "global" shadows, instead of underlining "local" sharp changes in lighting (however, I think this is exactly what your example image is doing).

With that in mind, I think you can start with a very simple Compositing Nodes setup:

Take your RenderLayer input, and between it and the output, add a "RGB to BW" and a "ColorRamp" node.

Move the sliders around on the ColorRamp node to find your highlight/shadow range.


Cloth is going through the collided ball

The vertexes in the curtain are getting stuck inside the ball--You'll want to increase the collision distance:


How to lock the position of one of my bones?

Maybe you should explain more precisely what is your case. But for example, you could unparent your bone in Edit mode, then in Pose mode, give it a Child Of constraint (press the Set Inverse button to keep the bone at its original position). When you'll need the child bone to be unparented, you'll simply create 2 Influence value keyframes: at frame X-1 you'll keyframe an Influence of 1, and at frame X you'll keyframe an Influence of 0.


It is posible to obtain a armature from a Rig?

create a copy transforms constraint on each of your bones and set the rigged armature's bones as target. then bake the animation by selecting clear constraints.
for baking see baking with reference question


How do I create an oblong torus with a constant thickness?

If you stretch a torus, both the major and the minor radii will be stretched, so the effect you see is perfectly normal. There may be some way to remedy that, but I haven't found it. I have come up with some workarounds though.

Method 1

Add a mesh circle.
Tab into Edit mode1.
Scale it along one axis, SX or SY.
Tab back to Object mode.
Convert the circle, which should now be an ellipse, to a curve AltC > C.
Put a bevel on it. If you want a circular tube, you needn't use a bevel object. Just set the bevel depth and resolution to whatever rocks your boat and set Fill to Full.
When you're happy with it, convert it back to a mesh AltC > M.
Unfortunately I haven't been able to find out how to include the menus when I take screenshots, so this doesn't show the conversion between mesh and curve and back.

The reason I don't use a curve directly, is that neither Bezier nor Nurbs curves represent elliptical object very well. They approximate circles acceptably, but with ellipses they fail miserably unless you give them a ridiculous amount of vertices.

Method 2

If you have the Extra Objects addon installed and activated, you can use XYZ Math surface to create a torus object of practically any shape.

To enable this addon, go to User Preferences CtrlAltU > Add-ons > Add Mesh > Add Mesh: Extra Objects.

Add > Mesh > Math Function > XYZ Math Surface

For an elliptical torus with a major axis of 3, a minor axis of 1 and a circular tube with a radius of 0.25

X equation:
(3+.25*cos(u))*cos(v)

Y equation:
(1+.25*cos(u))*sin(v)

Z equation:
.25*sin(u)

U min and V min: 0
U max and V max: 2*pi
U wrap, V wrap and Close V enabled.

The normals will be pointing inwards, so you'll need to flip them. Tab into Edit mode and hit CtrlN to recalculate them to point outwards.

Method 3

Here's a third method that I discovered today, when reading this question. It uses the Skin modifier, which is something I've never used before. This seems to be the simplest method, and very straightforward, and that's the reason I'm making this late addition.

Add a mesh circle.
Tab into Edit mode1.
Scale it along one axis, SX or SY.
Tab back to Object mode.

Add a Skin modifier.

Add a Subdivision Surface modifier. As pointed out by PGmath in a comment to this answer, the Catmull-Clark algorithm doesn't produce a perfect circle, and depending on your need for accuracy in the shape of the skin, you may want to consider using one of the first two methods instead.

The radius of the skin can be scaled. Make sure the Skin modifier is still in the modifier stack, i.e. do not apply it.
Tab into Edit mode.
Make sure everything is selected (A once or twice).
Press CtrlA and then drag the mouse or use the arrow keys on your keyboard until you're happy with the thickness. Enter or left mouse button to confirm.

1Scaling in Edit mode is essentially the same as scaling in Object mode and then applying the scale.


Why the blender browser plugin is not updated?

As an alternative.  You can also have a look at blend4web which can directly export to an HTML file and since it uses WebGL, no browser plugin is needed.   It can also export to a more programmer oriented format for use with some of their other tools.

So far as I know, it is not yet capable of using BGE logic bricks however b4w is being updated regularly and can already be used to make really nice looking browser games.  There is also a lot of documentation available so getting started should not be too difficult.

https://www.blend4web.com/en/

Here is a BA.org thread that is currently being maintained by an employee of blend4web  http://blenderartists.org/forum/showthread.php?333214-Blend4Web-a-3D-web-framework-for-Blender-artists


My laptop gets too hot when rendering in cycles

I have the same laptop, and it does indeed get hot. But this isn't really an issue specific to Cycles or even this laptop, any CPU / GPU heavy computation that has good multithreading will do it, and laptops often just aren't made to run cool under such loads.

I suggest to use CPU rendering with a lower number of threads like 2 or 3 instead of using an automatic number of threads. This mobile GPU isn't faster than the CPU in most scenes anyway. Cycles doesn't have an explicit way to specify using fewer GPU cores, though you could try decreasing the tile size to make it render slower and hopefully get it to run cooler as well then.


How to create a super fine wireframe with low poly?

You could try something like this - material only, no geometry.

All it is really, is a mix of two separate Wave Textures (on different axes), clamped by ColorRamps to make sharper "ridges". I softened the effects of the procedural textures (noise and wave) in a few places using MixRGB nodes, mixed with white, and I ran the (multiplied) result of the 2 Wave textures through a Bump Node and into the Normal input of the Principled BSDF.
I slightly warped the input vector using a Noise Texture so the result isn't so "gridlike", and I mixed a bit of Ambient Occlusion shadow effect to make the ridges "pop" even more.


The number pad hot keys still work in 2.8. Have you remembered to re-apply emulate numpad in system preferences, because it is a new version of blender so the settings will be set to default (I made that mistake myself :) Also you can use the button next to the 1 to switch through lots of different views in 2.8. I think that may have been mentioned in the above answers. Hope I could have been of some help!


How to make objects follow an elevated curve yet stand straight?

Vanilla Blender can do it perfectly fine!
I found a bug which we can abuse to get the wanted effect ;)
The setup is incredible simple as well. Just make your curve with your array and curve modifier like normal. Then it obviously is not looking like what we would want, but then notice what happens if you scale the curve object in object mode.
To get the wanted effect, just scale the curve in object mode along the z axis to 100 or 1000 of its height. Then go into edit mode and reduce the height by scaling with 0.01/0.001 respectively. This is the result:

EDIT:
In my first test Tilt needed to always be 0.0, but further testing showed, you sometimes need sligthly different Tilt values, but I'm not sure why. That will solve your deformation issue though.
If you only use flat bezier handles (scaled to 0 on the z axis) a tilt of 0.0 everywhere is perfectly fine.


Particle System ignoring my vertex group density

Because vertex groups only consider vertices, not faces, so the influence of a vertex will extend until the next vertex:

We can see it if we switch to Weight Paint mode:

So what you need to do is create additional edge loops where you want the particles to stop, and make sure thay are not part of the vertex group:

Here is what it will give:


The armature itself doesn't store all the bone shapes ('Custom Object' in 2.8+), it just references them (or the bones do). This means that when you append an armature that is using custom bone shapes it has to append the objects that are being used as the custom bone shapes as well. So what you are seeing is the armature and the custom shape objects it's referencing.

If you're in 2.79 you can just move the bone shape objects to a new layer or if you're in 2.8 you can move them to a new collection and hide them.


Sculpting is hard. Any other way to make a drop?

Start with your dropper object, and add a loop cut where you want your paint line to be.

Select the whole bottom (painted) section, right-click and choose "extrude faces along normals" to bring the sides out a little bit (to mimic paint thickness).

Bring down the bottom center of the dropper and scale it inwards to make a "point".

Extrude the center section a couple of times and then scale the center line to make a shape like this:

To make everything round, add a Subdivision Surface Modifier. You may need to add some supporting geometry (such as the highlighted loop cut) to control the roundness the way you like. Don't forget to right-click and shade smooth when you're done.

Finally, just assign the correct materials to the different sections.


It's because your empty is not at the same location as your object origin, so the distance between the origin and the empty shifts the iterations. What you can do is:

Select the object
Press ShiftS > Cursor to Selected
Select your empty
Press ShiftS > Selection to Cursor

It should work.


Why are these fluid particles not being blocked correctly?

The most possible reason for that behaviour is non-manifold geometry.

When closing particles within the lamp by filling a face inside of the lamp, you create non-manifold mesh which might be hard to deal with for engine. Particles fly through from the bottom, where the face is created and which should block them.

To make the mesh as manifold one, first delete that inside face. Then you'll need to:

Solidify the mesh (either with Solidify modifier or by extruding geometry in Edit mode and scaling extrusion a bit inside).

Create a face which will block particles. For that, select edge loop, left from original face, bevel it with Ctrl+B and fill 2 new faces (they will be Ngons, however it doesn't really matter here).

Beveled edge loop:

Filling new faces:

Particles will  fly inside and collide with walls as expected:


On Mac you can access and manage presets from
Finder
Go (upper menu) hold Alt key to bring Library on the list
Library > Application Support > Blender > 2.93 > scripts > presets
or
Go to Folder shift+cmd+G
and paste this path directory
~/Library/Application Support/Blender/2.93/scripts/presets/

Terminal
cd ~/Library/Application\ Support/Blender/2.93/scripts/presets/

Notes: In all cases change the number 2.93 to your current Blender version you use. Specifically Sapling's presets are stored in sub folder operator > add_curve_sapling. Difference in path for Finder and Terminal is just in representation of space character in name of Application Support - Terminal use back slash and space.


How to make this script compatible with Blender 2.8 API?

Here is the Script converted to 2.8
import bpy

def reset_shape_keys ():
    for name, shape_key in get_active_block().items():
        shape_key.value = 0

def get_active_block ():
    block_id = bpy.context.object.active_shape_key.id_data.name
    return bpy.data.shape_keys[block_id].key_blocks

def select (selection):
    bpy.ops.object.select_all(action='DESELECT')
    selection.select_set(True)
    bpy.context.view_layer.objects.active = selection

def select_last_shape_key ():
    shape_key_count = len(get_active_block().items())
    bpy.context.object.active_shape_key_index = shape_key_count - 1

def remove_shape_keys (object):
    selection = bpy.context.object
    select(object)
    shape_key_count = len(get_active_block().items())
    select_last_shape_key()
    for i in range(0, shape_key_count):
        bpy.ops.object.shape_key_remove(all=False)
    select(selection)

def apply_modifiers (object):
    selection = bpy.context.object
    select(object)

    for key, modifier in object.modifiers.items():
        if key != 'Armature':
            bpy.ops.object.modifier_apply(apply_as='DATA', modifier=key)

    select(selection)

def super_apply_modifiers ():
    original = bpy.context.object
    bpy.ops.object.duplicate_move()
    backup = bpy.context.object
    backup.name = 'backup'
    remove_shape_keys(original)
    apply_modifiers(original)

    for key, shape_key in get_active_block().items():
        select(backup)
        bpy.ops.object.duplicate_move()

        meshed_shape_key = bpy.context.object
        select(meshed_shape_key)
        reset_shape_keys()
        get_active_block()[key].value = 1
        bpy.ops.object.convert(target='MESH')

        select(original)
        meshed_shape_key.select_set(True)
        bpy.ops.object.join_shapes()
        select_last_shape_key()
        bpy.context.object.active_shape_key.name = key

        select(meshed_shape_key)
        bpy.ops.object.delete(use_global=False)

You can write the bpy.ops.object.duplicate_move() like this because your only use the default values of this operator.
[Tested on 2.83.3]


Good question Austin,

---the below answer is if you want to render a file which has audio embeded, not for if you are having trouble playing back an audio file in the Video Sequence Editor---

Once you have audio in the video sequence editor, you're halfway there.

So you need to change your render output settings in the render tab

Change it to a video format (I normally pick h264)

Then change the wrapper format to Quicktime MOV, and the codec to h264  or PNG if you need lossless quality.

Below that, change the audio codec from none to AAC or MP3 (they're the ones I have had most luck with)

And then hit render and it should be in the final render output file (a .mov)


Set up a bone that only effects part of the wing and animate the bone so it moves the wing up and down. There are many tutorials showing how to use bones, but really select the faces that you want to move than assign them to the bone. By moving the bone, parts of the mesh move, but not all of it.


How to maximize a view from quad view (ex. front ortho)?

In Quad View, you have to toggle off the Lock button first, then move the mouse cursor over one of the four views, press Ctrl Alt Q again.


How to stop Blender from slowing down zooming and panning?

I know this post is very old, but what I do is if I want to work up close, I switch to object mode, deselect everything, zoom in about where I want to be, then go back into edit mode. The zoom scale is reset from that point. So basically, the zoom scale will always be there, but wherever it starts is wherever you go into edit mode with nothing selected.


Cycles is painfully slow even for the simplest of scenes

Make sure you dont have "Square Samples" checked.


Scaling (set of stairs) between two edges

If I got what you asked, try this:

get the desired length selecting the mesh delimiting the available space (in the image it seems a sort of cubic shape), and copy the Y dimension in the properties panel.

Then select your stair made of array-copied steps, and in the same panel it should have a different value:

now paste the copied value in the Y dimension.

it should fit perfectly


Can you make a custom mouse cursor for the game engine?

You can use python to do this, for example using essentially the script from this answer by Mike Pan:

from bge import logic, render
render.showMouse(False) # hide default cursor

def mouse2world():
    z = 1 # distance for cursor

    cam = logic.getCurrentScene().active_camera
    vec = cam.getScreenVect(*logic.mouse.position)
    camPos = cam.worldPosition
    projectedPos = [0,0,0]

    projectedPos[0] = camPos[0] - vec[0] * z
    projectedPos[1] = camPos[1] - vec[1] * z
    projectedPos[2] = camPos[2] - vec[2] * z

    return projectedPos

def main():

    cursorObj = logic.getCurrentScene().objects['cursor'] # where 'cursor' is the name of object to use as a cursor
    cam = logic.getCurrentScene().active_camera
    pos = mouse2world()

    cursorObj.worldPosition = pos
    cursorObj.worldOrientation = cam.worldOrientation

To use this, add an always sensor to the camera and enable true pulsing (you can add the sensor to any object, but I think it's more intuitive to put the logic bricks on the camera..). Then connect it to a python controller with the script:

Example file


How do I mirror one side of an object to another side that's already there?

I'm going to provide 2 solutions to this answer: mirroring the side with the cone shaped holes, and secondly extruding that side to give bullet chambers that pass all the way through. Feel free to use either option.

Solution 1 - Mirrored Side Option

Delete the duplicated object Drum.001
Enter edit mode on the Drum object
Change selection mode to Edge and select an edge that connects both side of the cylinder.
Select S - Cursor to Selected (make sure you don't move the cursor after this step)
Select all the verts on the end that you are not keeping and delete.
Select all the verts on the other side that you want to mirror, and Shift D to duplicate
Press the . key to change the pivot type to Cursor
S Y -1 to scale along the y axis in the negative direction. This should copy your verts to the other side of the cylinder.
Select all, and Remove Doubles
Select all, and do Limited Dissolve (this is optional but it makes connecting the two side easier in the next step).
In edge select mode select the outer circle of both sides. Then SPACE and type Bridge to find the Bridge Edge Loops command.

Solution 2 - Extruded Side

Delete the duplicated object Drum.001
Enter edit mode on the Drum object
Change selection mode to Edge and select an edge that connects both side of the cylinder.
Select S - Cursor to Selected (make sure you don't move the cursor after this step)
Select all the verts on the end that you are not keeping and delete.
Select the tips of the cones and delete. You should now have one face with 6 holes in it.
Select all, and Remove Doubles
Select all, and do Limited Dissolve (this is optional but it makes connecting the two side easier in the next step).
Press the . key to change the pivot type to Cursor
With all verts select press E to extrude and Enter.
S Y -1 to scale along the y axis in the negative direction. This will move your extruded side to the other location giving you a full cylinder with 6 bullet chambers that pass all the way through.


The bevel feature in question wasn't added until Blender 2.63 and shortcuts weren't added until 2.64 so CtrlB won't work.


One thing that really improves Booleans is the 3D printing tool add one. Enable that (it is not enabled by default in 2.81) and then view it from the side menu at the top right. You can e it to check that everything is manifold and all your normals are correct and so one before you do a Boolean


Looks like you have intersecting or non-manifold geometry and the problem are aliased edges. There is no way to bake the AO with anti-aliased intersecting edges, that is not yet supported.

There are 3 option:

get rid of the intersections (or non-manifold sections)
bake a much much higher resolution and then downscale the texture
go over those edges with paintbrush and fix them manually


how to get camera exactly like in the z perspective view

Top view for camera has no translation or rotation.
See.
Align camera to view precisely and automatically, without manual fiddling
How to convert current view as camera?

Oops, realized after making gif q asked for perspective rather than ortho. ie don't change to ortho, however ortho is IMO may be a better way to make text look 2D.
In the cameras property boxes, can clear both location and rotation, to have the camera facing downwards.
Via shortcuts / menu with
AltG  Object > Clear > Clear Location
AltR  Object > Clear > Clear Rotation
Then move up in $z$ and set camera type to perespective
Here is a script to do this, moving the camera to 2 bu directly above origin.
import bpy

context = bpy.context
scene = context.scene
cam = scene.camera

cam.matrix_world.identity()
cam.data.type = 'PERSP'
cam.matrix_world.translation.z = 2


How to get rid of shadowy texture on objects?

It's hard to tell from the images alone what you mean, there may actually be two different issues at play here.

As mentioned by Mr Zak you could easily make your arrows shadeless either by

Increasing Emission -  This will make the object as if it were emitting light, it will partly retain shadows and glossy reflections (with the right render settings you can even actually maker them glow if you render with Blender Internal)
Turning on the option Shadeless under the Properties Window > Material Options > Shading - This Will make your object flat colored, as if it were bi-dimensional, no shadows, no glossiness, or shine, and no light emission (basically doesn't react to lighting)

There is another issue at play here, that may be slightly messed up normals which will yield weird or unexpected shading. Use an edge split modifier on all your objects to make shading as expected.

Have in mind that switching to Blender Cycles may not be a full lasting solution on it's own, it will require setting up materials and scene differently from scratch since they are two completely separate and independent render engines, and Blender Internal materials are incompatible with Cycles and vice-versa


some kind of dynamic and localized subdivision surface modifier - type algorithm?

Well, as I originally suggested in the previous question, you can always try using the Remesh modifier.
It dynamically generates a clean mesh with ~equal size quads out of the volume of your mesh.

I'd recommend using the smooth mode and an octtree depth of 7 or more to get accurate reconstruction of your mesh.

ADDED: It also helps to add a smooth modifier on top of the remesh modifier, because the mesh generated by the remesh modifier is still a but funky due to the issues with the original mesh.

Here's a code snippet you can add to your script:

myObject.select = True # Replace myObject with a reference to your actual mesh object
bpy.context.scene.objects.active = myObject

bpy.ops.object.modifier_add( type = 'REMESH' )
m = bpy.context.object.modifiers['Remesh']
m.mode         = 'SMOOTH'
m.octree_depth = 7

bpy.ops.object.modifier_add( type = 'SMOOTH' )
m = bpy.context.object.modifiers['Smooth']
m.iterations = 26

It's not exactly what you asked for, but might do the job nontheless.

ADDED: You only need to add this modifier once, of course (it will adapt to changes in your mesh), but it will slow down your script considerably, since the remesh modifier takes quite a bit of time to calculate, especially in the higher octtree_depth levels.


Your problem is that even though you used all quads, they do not flow with the muscles underneath and they do nothing to describe the form other than define a surface. You need to watch some of the tutorials on retopology and you will see how they create loops around the eyes, mouth etc. and join them to create a mesh that is easy to animate with rigging, as well as low poly enough to properly uv unwrap and texture. High resolution sculpts can be used to derive the form and the lower poly mesh is what you animate and bake the details to.

Sorry you got such non constructive criticism, but that seems to be the norm on the internet. I would suggest taking a look over at some tutorials on CGCookie.


How to select loops with 'emulate 3 button mouse' and 'LMB select' enabled?

In blender 2.8 it is double left click to select a loop if the Emulate 3 Button Mouse is checked in settings.


Blender 2.49b: Loop animation between selected markers

The options I was looking for were indeed trivial. Nor did the pose markers have anything to do with the looping.

On the Timeline window, select "Frame" menu, followed by "Set as Start (Shift s)". This merely means that if the animation starts before this point, it will advance normally until the end point, following which it will loop in-between the current start and end points.

One can see the start and end points in the image in the OP by noting the section of light gray in the timeline window (Which also happens to match up with the pose markers, implying that they have something to do with the looping; they don't.)


The UV layout for this model makes selecting rows very easy with the Box Select tool.  (I hid the ends because they have hidden faces that are causing problems.)

By selecting every second loop of the UV's and then using Tris To Quads, you can establish guide loops that allow you to use the tool again and achieve consistent results.

b for Box-Select.  Also make sure to activate the icon for use_uv_select_sync as shown in the animation.

Now use Tris to Quads on the selected rows, then select everything and repeat Tris To Quads.

Now you can repair the few mistakes by using the Join tool j.  In the following case, I used Join and then used Make Face f to make a quad at the center of the error point.


You can use the new Wireframe modifier to do this. It will convert edges into solid geometry:

Or you can use the old Wireframe tool:

Select your mesh and enter edit mode (Tab)
Select all (A)
Press CtrlF> Wireframe.


How can I programatically evaluate each pixel before final composition?

An example of a pixelated image in the compositor.  This may help for one part of your question.


Blender 2.8 render wireframe select specific edges

To hide the edges between faces that lay on the same plane, use a Decimate modifier above your Wireframe modifier.

Set it to Planar mode, and adjust the angle limit if needed.

The inconsistent line thickness is caused by the original mesh having been scaled up in the three dimensions with different scale factors. The mesh "remembers" these factors and applies them to the modifier results, making the wireframe stretched weirdly. To fix the problem, you must make the mesh "forget" that it has been stretched, and make the new scale permanent ("Apply" the transformation). To do so:

select the object
do Ctrl+A > Scale.


Is there a blender script or way to configure Blender to do this (Retopo)

You could try the Bsurfaces addon:
https://www.youtube.com/watch?v=YQb5lHDFjjs
(The video also activates another add-on).
I haven't tried it myself (new blender doesn't work on my laptop)
but looks simple enough for me.


Auto-saved files are located in the same directory as your .blend file inside folder "auto_save".

To take script works you have to save your .blend file first.


Square - Octagon - Circle - Modelling puzzle

in my opinion you are going fine, remember that there are many ways to achieve what you want in Blender, so in this case I see two other possibilities.

Option one:

You can add the flat base geometry.

Select and erase these vertices

Add a mirror modifier like this

And then extrude

Option Two:

Use Boolean

Add a cube

Add a 8 vertices cylinder

Add a Boolean modifier to the cube like this

To look the cylinder in wireframe only, go to Object menu > Display > and set Maximum Draw Type to Wire

Repeat the previous steps with the other geometry, at the end you will have something like this

Now when you're ok with the look, just apply the modifiers and done.


How can I rotate a cylinder in such way that one of its faces would be perfectly aligned along one of the global axis?

If the face you want to align is the top/bottom one, you can do so when you create the cylinder by pressing align to view (you have to align your view first, 7 for top view etc). For one of the side faces, you can compute the angel and type it in while rotating. For 8 faced cylinder, the angle from the center to the face is 360/8 -> 45 degrees to rotate by one face. The cylinder is perfectly aligned when you create it, so you can just press R and type in the angle. You can also compute the final rotation and type it in in the object menu.


First create a texture in the properties window:

To add the texture in the compositor use an input>texture node, and select the texture you've just created:

Then overlay that on to the background image. You can control the size and shaprpness of the noise by adding a value node and a blur node.

(click on the image to enlarge)

To make it change from frame to frame you can keyframe the values.

Another note: try other forms of noise like Clouds, Musgrave or Stucci to find the texture pattern that matches that of your rendered model's


What is a good workflow between blender and 3d coat?

I also use 3D Coat, the built in AddOn helps a lot. You have to go into preferences and enable it.
My workflow is: Sculpt Highpoly in 3DCoat, retopo and lowpoly in 3DCoat, Exporting Highpoly and transfering the lowpoly to Blender for unwraping, after that just baking in xNormal.


How to create cylinder with varying radius at different height

Bmesh script.

Here is but one of may ways could approach this.
Rib n Bridge

Make growth_segments cirlcles all with segments segments.  Each
has a radius in range (min_radius, max_radius) and the the next is
in the range of  (min_growth, max_growth) above.
A translation matrix, using the accumulative height is used to place
each successive circle.
Each circle is added with bmesh's create circle primitive. On each
iteration a "rib" is the last added segments edges of the bmesh.
Skinned by bridging each rib with its next.
Finally the first and last ribs are ngon filled with the
contextual_create operator, somewhat akin to bmesh's F
"fill" key.

import bpy
from bpy import context # for testing
import bmesh
from random import uniform
from mathutils import Matrix

segments = 16
min_radius = 0.5
max_radius = 2.0

growth_segments = 10
min_growth = 1.0
max_growth = 2.0

bm = bmesh.new()

h = 0
ribs = []
# make the circles
for i in range(growth_segments):
    bmesh.ops.create_circle(
            bm,
            segments=segments,
            radius=uniform(min_radius, max_radius),
            matrix=Matrix.Translation((0, 0, h)),
            )
    h += uniform(min_growth, max_growth)
    ribs.append(bm.edges[-segments:])

# bridge the loops
for rib, ribnext in zip(ribs, ribs[1:]):
    bmesh.ops.bridge_loops(
            bm,
            edges=rib + ribnext,
            )

# fill the ends

bmesh.ops.contextual_create(
        bm,
        geom=ribs[0] + ribs[-1],
        )

# Create object load mesh
me = bpy.data.meshes.new("RandomCyl")
bm.to_mesh(me)
ob = bpy.data.objects.new("RandomCyl", me)
context.collection.objects.link(ob)
# make selected and active
ob.select_set(True)
context.view_layer.objects.active = ob

Matrices
Have used a matrix in the create circle operator to translate to the height

Here I've extended this a bit further to give a panel beaten effect, each rib is now a random ellipse using above min max for two radii, and also rotated randomly 0 to 45 degrees in Z.
A diagonal matrix is a quick way to produce a scale matrix.
Sx = Matrix.Scale(4, 3, 'X')

is equiv of
S = Matrix.Diagonal((4, 1, 1))

Each circle is transformed by R @ T @ S (rotation, translation, scale)
    bmesh.ops.create_circle(
            bm,
            segments=segments,
            radius=1,
            matrix=(
                Matrix.Rotation(uniform(0, 0.7854), 4, 'Z') @
                Matrix.Translation((0, 0, h)) @
                Matrix.Diagonal(
                    (
                    uniform(min_radius, max_radius),
                    uniform(min_radius, max_radius),
                    1,
                    )
                ).to_4x4() # since tanslation mat is 4x4
                ),
            )

Cannot emphasize enough, the better we become at using linear algebra (vectors and matrices) the "easier" it will be to use API methods. Is also generally faster and IMO cleaner.
Spin Profile
Another way would be to make  profile edges on XZ plane and spin it around z axis to make a solid of revolution.

Equivalent of making profile shown on left, and creating mesh by spinning it with the screw modifier (default settings)
import bpy
from bpy import context # for testing
import bmesh
from random import uniform
from mathutils import Matrix
from math import radians

segments = 16
min_radius = 0.5
max_radius = 2.0

growth_segments = 10
min_growth = 1.0
max_growth = 2.0

bm = bmesh.new()

h = 0
verts = [bm.verts.new()]

for h in range(growth_segments):
    radius = uniform(min_radius, max_radius)
    verts.append(
            bm.verts.new((radius, 0, h))
            )
    h += uniform(min_growth, max_growth)

verts.append(bm.verts.new((0, 0, verts[-1].co.z)))

for edge in zip(verts, verts[1:]):
    bm.edges.new(edge)

# spin the sucker

bmesh.ops.spin(
        bm,
        geom=bm.edges[:],
        axis=(0, 0, 1), # z axis
        angle=radians(360), # 2pi one rev
        steps=segments,
        )


How can I avoid Undo/Redo on StringPropery or bpy.props in general?

Setter and getter saving data outside blend file data.
Suggest this could be done with a setter / getter. For example could append string property to a text file, which would be outside the influence of the blend file data (undo stack.)
Here is a test example, using a hardcoded filepath to a text file.  The property is prepended to the text editor footer to test.

import bpy
from bpy.props import StringProperty

from pathlib import Path
filepath = "/tmp/test.txt"

def get(self):
    f = Path(filepath)
    if f.exists():
        return f.read_text()
    else:
        return "Default"

def set(self, value):
    f = Path(filepath)
    f.write_text(value)

bpy.types.Scene.foo = StringProperty(
        get=get,
        set=set,
        )

def draw(self, context):
    scene = context.scene
    self.layout.prop(scene, "foo")

bpy.types.TEXT_HT_footer.prepend(draw)

Note: This is solely a proof of concept. Would require a blend file name based filepath, or in file data for different values on a per blend basis.


Cycles render is different when rendering with GPU

I'm using a HDRI lighting in my scene which is not yet supported in OpenCL. Anyone knows when it will be supported?

Well i just had a look at the supported features page, and it says that HDR float isn't supported yet with opencl

blender.org/manual/render/cycles/gpu_rendering.html

"OpenCL: No support for HDR (float) textures at the moment.".


When Animating the Eye with the "Track To" Constraint, the location of the mesh changes. How do I fix this?

It is hard to see the "how to" in the context you describe, but here is an approach for rigging the eyes.

Create an armature
Add bones for the eyes to this armature (keep a main bone, extrude and set it as not connected bone)
Place these bones to the center of the eyeball (place the 3D cursor in the center and place the bone at the 3D cursor, use Shift + S)
In object mode, select the eyes, then the armature and Ctrl + P and "with automatic weights"

At this step we may have something like this :

Create 3 empties (bottom of the image below)

2 empties for the eyes, with a little convergence. 1 empty to drive the 2 previous. Parent the two first with the last empty.

Back to the eyes armature

Go to pose mode (for a direct answer, this point 'pose mode' is probably the problem in your question).
Select the left bone and add a "track to" constraint. Set the corresponding left empty as target.
Then do the same for the right eye.

It is done :

Eventually, you can parent this armature to your current armature, but I think this is better to incorporate all in your armature.


Okay, my original answer was wrong. Try experimenting with Orientation Axis and Randomize Phase