As a Roblox developer, there is currently no way to apply a scale or size to a bone.
Writing a CFrame with a scaled matrix to the WorldCFrame property does not solve my problem because Roblox orthonormalizes the CFrame upon setting.
If Bones had a Size property, I could implement cool effects which involve selectively scaling sections of a mesh, or dynamically rescale parts of a mesh for editing a character’s proportions.
The reason they dont, is because bones are derived from attachments, which dont have a scale property. If the team behind implementing skinned meshes would have made a new class instead of deriving it we might have gotten it! so yeah +1 on this, its really useful at times.
Every single object type is “derived” from the Instance class, that does not mean that they cannot have their own unique APIs that they add onto the base Instance class just for themselves. It is how Terrain can have a WaterTransparency property even though Instance does not. There is nothing stopping the engineering team for this sort of stuff from adding a Size property to the Bone class, there just might be difficulty implementing it in a functional and sensible way.
Yes, i know they are derived from the Instance class.
I just mean they could have made a new class that derives from Instance, instead of Attachment.
But how would that change anything? They can still add a .Size property to Bones, deriving directly from Instance just means more work on their part when Bones need very similar properties and functionality to Attachments and they could just use that, add some code on top for the actual mesh manipulation, and call it a day.
I’ve been eagerly waiting for bone scaling for a long while now, or at least for someone to say they are working on it.
+1 on this. This would especially be useful when importing animations from blender that change size of bones.
I absolutely support this feature request!
Making cartoony animations in roblox with stretching and squashing is currently almost impossible but something I enjoy doing with Blender.
But of course since bones don’t have a size property I cannot export animations with stretching and squashing.
Roblox is unbelievably limiting with animations in general.
While they’re at it I’d also love to have extra ways to blend animations such as additive/subtractive blending.
Support!
Being able to directly set the size either by Transforming or Direct set would do wonders for custom rig animations :\D
You’d think with how much they’re pushing layered clothing and editable meshes we’d at least get something for bone scaling.
Bump, why this isn’t a thing genuinely doesn’t make any sense to me.
Bump, would add so many possibilities
So need this. What really does not make sense is that you can change the size of bones in studio, but there’s no way to scale them via script. ???
I support this. Bump!
Please consider this.
why is this not a official feature yet :C
Bump
I’d love to see this as a feature!
I’ve talked to the animation/avatar team at RDC, this feature is considerable but the problem is the fact that bones are derived from attachments, adding scale is a bit difficult, the whole visualisation of bones and stuff has to be changed while still maintaining backwards compatibility, but it has been considered. :>
please implement this, it would be a great feature 
All other engines have this, why not Roblox? It’s just another property to lerp. Support!