I am wondering if there is a way in Blender to show a derivative graph (f)curve of the speed of an attribute. I have searched the forum, but was unable to find anything about this.

In After Effects, if you right click inside the Graph Editor, you can choose between "Edit Value Graph" and "Edit Speed Graph". The speed graph really helps understanding the acceleration (or easing) of objects. Therefore I'm looking for a way to show me this info in the Blender Graph Editor.

Using the Animation Nodes add-on (which is amazing!) I already created a speedometer to show me the current speed of an object in km/h. Useful, because I'm animating cars on a highway. But it's hard to see the slowing down and speeding up of the cars in slopes of the fcurves. Hence my question :D

I did find this post about calculating the derivatives, which touches upon the subject, but does not quite goes as far as I want:

https://blenderartists.org/forum/sho...ght=derivative

On reddit someone posted the same question, but unfortunately there was no real answer to his question there:

https://www.reddit.com/r/blender/com...peed_graph_on/

Hope someone has a genius tip on how to accomplish this!

Thanks! ]]>

I am currently creating an external Python script (for use with MatPlotLib library) that use the same maths and similar functions to the way Blender imports a .bvh and creates the rotation keyframes for each bone in the armature.

I have access to a database of .bvh mocap data that I must analyze using TensorFlow and am now eager to find a way to re-write some functionality into a custom application.

Synopsis:

I have been examining the contents of import_bvh.py (file on GitHub: Link) and have come to the conclusion that my external application seems to be mostly correct except for the bone_rest_matrix (line 569) which I believe is in Blender's bone space (or possibly Armature space)??

I do not know how to reproduce this value for a given armature (eg. the armature created in the MatPlotLib app).

When I look closely at import_bvh.py I see that it creates an armature and object (line 380) it then sets the bone.head and bone.tail (line 419) for each bone in the list of imported bvh nodes. But I do not understand how it sets the bone roll.

Also I notice that the left and right arms have different Up pointing orientations, so I assume the roll is local and not globally determined.

Objective:

I have been given some armature hierarchical data and I need to somehow compute the correct bone_rest_matrix so it can be used to extract the bone's Euler angles from the homogeneous coordinates:

Code:

`euler = Euler(bvh_rot, bvh_node.rot_order_str[::-1]) #input Eulers`

bone_rotation_matrix = euler.to_matrix().to_4x4()

bone_rotation_matrix = (bone_rest_matrix_inv * #NEED TO COMPUTE THIS (Inverse)

bone_rotation_matrix *

bone_rest_matrix) #NEED TO COMPUTE THIS

rotate[frame_i] = bone_rotation_matrix.to_euler(pose_bone.rotation_mode, prev_euler)#output Eulers

prev_euler = rotate[frame_i]

I am also not sure what "prev_euler" is doing or why it was required (I am not sure if it is part of the bvh decoding algorithm or just some Blender internal math stuff).

Any help here in understanding what this matrix represents or how to reproduce it would be amazing!!!

Thanks ]]>

i just rigged a human body and animated it. Then i loaded it into Unity and saw, that certain vertices where not properly bound to their bones anymore (they just did not move or did not move correctly. After that i found out, Unity only supports vertices bound to maximum 4 bones (UE4 supports up to 8 bones - but with a slight perfomance drop if you use more than 4 bones per vertex). After that i used the "Limit Total".-function of the Weight Tools in Blender. After that the mesh-deformation was also strange in blender - as expected ... So far so good but now my question:

Obviously i have to fix this strange mesh-deformation issues after i limited up to 4 bones for each vertex but if i begin to weight paint it by hand to fix it, vertices are put in multiple vertex groups again (due to the weight painting) and i end up with nice deformations but again with vertices that are assigned to more than maximum 4 vertex groups ...

Does anyone know how to get around this problem? Maybe Blender has some smart tools are there is a best-practice to avoid this problem. ]]>

This would be the equivalent of grabbing all the keyframes on a f-curve and moving the curve up and down.

The propagate tool just overwrites the keyframes after with the absolute value, but I need it to be relative. ]]>

I've created a helper empty that is rotated to the angle that I'd like my rotation to happen on. I have the gear door as a child of that empty. I create a key at frame 0 that is of type Rotation with zero rotation, then on frame 25, I rotate my gear door helper empty in local y (r-y-y) and then when I play the animation back, it looks way wonky...So I'm sure I'm leaving out something important here. Any thoughts? ]]>

(i want to do a path for a bullet, and the cam is also go on the same path, byt insted of doing the same move like the bullet i want to give the cam a little offset and go more up above the bullet) ]]>

ive tried making my own rigs but most of the time the animations end up looking messed up on valve models when i do that (in engine, tf2, sfm, etc) (but not on other models with the same armature for some reason...) ]]>

I have gotten into a project that involves a revolver being fired, along with physics to control the bullet after it's been fired. Each cartridge is composed of a bullet (the actual moving "tip"), and the casing/shell. I'm wondering on

I've already explored a couple options, however I've hit dead-ends on each one.

Firstly, I have the good ol' parenting a shot. However, the obvious issue is that it's impossible to keyframe a disconnection between a parent and child.

Secondly, I tried using child-of constraints. And while this seemed to give some promising results (after setting it up in the most painstaking way imaginable), they seemed to just revert back to some

Thirdly, I looked into the Dynamic Parenting plugin, which seemed great at first; however, as soon as I went to play the animation, each cartridge got all jacked up and didn't want to cooperate. I then had to undo this to get them back to their desired state.

Are there any other feasible options? I've tried everything within my current knowledge. Any help is appreciated, and thank you!

The Blend:

RevolverDynoPaint.blend

Or is it recommended/good practice to do it in order? ]]>

I cant see em in the timeline, dope sheet, anywhere. The animation is still there, but i dont have any way to modify the keyframes!.

I click in the mesh, to be sure, i go to the graph editor, but nothing is there. Thanks in advance. ]]>

I've tried everything I can think of, but for either it's a setting I don't even know exists, or there's something I fundamentally don't understand...

The file is attached, please, any help would be immensely appreciated!

Okay, so, it seems that the graph is just a bit weird with rotation, as perfectly smooth, circular turning is a Sine Wave, not a straight line...

hollow, everyone! I want achieve this effect in blender! what should i do? ]]>

I was wondering how would one proceed to transfer animations from one rig to another, assuming the rigs have the same bones but that their scales might be different. Is it at least possible ? Does anyone has some experience with it ?

Thanks a lot ! ]]>