update_delta_rts

[subin6]

Hi, I have a question about the following function, update_delta_rts.

banmo/nnutils/banmo.py

Line 1207 in c449803

def update_delta_rts(self, rays):

Why do you compute rays['bone_rts'] by multiplying (bone_rts_rst)^(-1) * bone_rts_fw in correct_rest_pose function?
Is it right that you intend to multiply bone_rts_fw first and then multiply the inverse of bone rest transformation?

What I understand is that you first transform bones using bone_rts_rst, which results in restpose bones.
(restpose_bones = bones_rts_rst * bones)

Then, you make time t transformation using bone_rts_fw and bone_rts_rst in correct_rest_pose_function.
(bone_rts_fw = (bone_rts_rst)^(-1) * (bone_rts_fw) )

As shown in the rendering code, bones_dfm is computed using those two values.
(bone_dfm = bone_rts_fw * bones_rest
= (bone_rts_rst)^(-1) * bone_rts_fw * bones_rts_rst * bones

What I'm curious about is that why you multiply the inverse of bone_rts_rst and bone_rts_rst on before and after of bone_rts_fw matrix? What's the meaning of this multiplication?

Hope to hear from you soon.
Thank you.