[Addon] Rigid body / spring physics for bones

[Pauan]

It’s almost feature complete, it’s well tested, and it’s very fast. But it could always use more testing (especially on real world projects).

It’s very safe and robust, but theoretically in extreme situations it could mess up your bone’s parenting, so make backups of your .blend files!

Also, don’t add any objects into the RigidBodyBones collection, they will be deleted.

Note that you need Blender 2.91.0 or higher, because of a severe bug in earlier versions of Blender.

Pauan/blender-rigid-body-bones

[cconst]

I test it a little, when I run the example file and try to move root bone the entire chain of bone breaks. Does this happen into yours as well?

[Pauan]

@cconst Thanks for trying it out. I don’t have any issues when moving the root bone either in Edit mode or Pose mode. What is your Blender version? And could you share a screenshot?

[cconst]

This is in 2.90.1

armatureanimations

Also this log appears all the time in console, if is helpful to mention.

[Pauan]

Thanks. As I explained, you MUST use 2.91.0, it will not work in 2.90.1 because of a severe bug in Blender.

[cconst]

OK, I tested it quite a bit. It was really easy to use. Some ideas about this:

• I was able to enable and use the addon in 2.90 despite not working at all. This means at least perhaps other users might run on LTS or something else. At least there should be a strong ban on the registration process not to allow the addon get enabled at all. Provide a nice warning message.
• One common use case I do is to select a dozen of bones and change the properties at the same time. Selecting-bone-changing-setting-selecting-bone-changing-setting is too much of a burden. Luckily I learnt somewhere deep in the forums that having multiple objects selected ALT+CLICK a property allows you change the same property for all the selected objects. I wonder if you know this trick - is perhaps one of the most hidden secrets of Blender. That way I could change some properties easily for multiple bones. However not easy to do on enabling Active bodies and such, it would lead to crashes. Something really good to consider if it can be solved somehow.
  
  
• Another idea is that relative settings could be grouped together so they are changed at once. Such for example, all stiffness values and all damping go together. Sliding along the value boxes and then setting the value only once, really useful that way. Checkboxes can be slided all at once however only input boxes that are grouped together should be slided, and that way you can’t hit X Stiffness + Y Stiffness in one go. Just a usability note here, in terms of organization your design makes sense, but is only a matter of speed here.
  

Generally, it was really good.

armature_test

boxer.blend.txt (812.1 KB)

[Pauan]

@cconst

At least there should be a strong ban on the registration process not to allow the addon get enabled at all. Provide a nice warning message.

It already specifies the minimum version: Link

According to the documentation, that should prevent it from being installed:

https://wiki.blender.org/wiki/Process/Addons/Guidelines/metainfo#blender

@cconst

I wonder if you know this trick - is perhaps one of the most hidden secrets of Blender. That way I could change some properties easily for multiple bones. However not easy to do on enabling Active bodies and such, it would lead to crashes. Something really good to consider if it can be solved somehow.

Yes, it is in the TODO list, but it is tricky because the add-on API does not give access to the bone:

How to access bone from PropertyGroup update function?

My addon uses a PropertyGroup (which is attached to EditBone). This PropertyGroup has various update callbacks which are used to update the bone when a setting changes. My goal is: if the user changes a setting it will only apply to the active bone, but if the user selects multiple bones and uses Alt, it will apply to all the selected bones. This is the default behavior of Blender. Normally I would use self.id_data to solve this problem, but that does not work with EditBone. Here is an exampl…

@cconst

Another idea is that relative settings could be grouped together so they are changed at once. Such for example, all stiffness values and all damping go together.

I copied Blender’s UI for rigid body and rigid body constraints, but I agree that grouping them differently would be better, so maybe I should make it different from Blender’s UI.

[Pauan]

@cconst I released version 1.1, it fixes all of the issues that you mentioned:

Release Version 1.1 · Pauan/blender-rigid-body-bones

[cconst]

Great. You can also jump to blenderartists.org to continue with further feedback in case you want to get more ideas about features and such. Or decide to split code into a lite free version and a commercial full-featured.

[Pauan]

I released version 1.2:

Release Version 1.2 · Pauan/blender-rigid-body-bones

[Pauan]

I released version 1.3:

Release Version 1.3 · Pauan/blender-rigid-body-bones

[Pauan]

I released version 1.4.1:

Release Version 1.4.1 · Pauan/blender-rigid-body-bones

[Pauan]

I released version 1.5.0 (this is a big release):

Release Version 1.5.0 · Pauan/blender-rigid-body-bones

[Pauan]

I released version 1.6.0:

Release Version 1.6.0 · Pauan/blender-rigid-body-bones

[Pauan]

I released version 1.6.1:

Release Version 1.6.1 · Pauan/blender-rigid-body-bones

[RomboutVersluijs]

Actually the wiggle bone has this feature. Add an update attribute to the prope and then loop over by.context.sepected_pose_bones. that should work

[Pauan]

@RomboutVersluijs That was fixed a long time ago: Release Version 1.1 · Pauan/blender-rigid-body-bones · GitHub

[RomboutVersluijs]

Think I was mixing this up with the other wiggle bone addon. Problem though, laptop users which use alt to pan and scroll won’t be able to use this

[Pauan]

@RomboutVersluijs I’m not really sure what you’re saying. Using Alt to make changes to several things at the same time is the standard Blender shortcut. That’s how it works throughout all of Blender. If somebody changes their settings so that Alt doesn’t work, then that will affect all of Blender, not just this addon. So that’s a problem that has to be fixed in Blender, there’s nothing I can do about that.

And in any case Alt is only a convenience, all of the functionality can be done without Alt. There is also a Copy from Active operator that will copy-paste the settings to multiple bones, so that can also be used.

[RomboutVersluijs]

Well in prefs there is a setting to simulate a 3 button mouse. This is done by using command key alt

By adding a update attribute to a prop you cN still update all items. It does need addition code for each prop to get this to work on all inputs