Question

I hope you can help me. My problem is with the collada’s skinning equation:

v += {[(v * BSM) * IBMi * JMi] * JW} 

• n: The number of joints that influence vertex v
• BSM: Bind-shape matrix
• IBMi: Inverse bind-pose matrix of joint i
• JMi: Transformation matrix of joint i
• JW: Weight of the influence of joint i on vertex v

Each vertex “v” must be calculated (i.e. through a “for” bucle). But, it`s not very, very slow if I have a mesh of 10,000 vertices or more? This must be calculated ever in real time? No other way to calculate “v”?

Thank you very much. 🙂

Answer 1

You can probably use a threshold JW – for each vertex v, you may skip further computation for any joint i on v where JWi is below some threshold.

Also you could precompute IBMi * JMi for each joint once, right?