Hello,
I’m trying to use skinning with collada and OSG. That’s my first skinning
experience.
The formula is given p 4-8 as:
outv = \Sum_i { ((v * BSM) * IBMi * JMi) * JW }
However v is in R^3 and BSM in R^{4x4} so the matrix product is not valid.
Am I missing something? What is the full formula?
I would have expected v to be replaced by [v(0) v(1) v(2) 1] but from my
tests with OSG, it seems more like [v(0) v(1) v(2) 0]. As a consequence
one cannot move the vertices located at [0 0 0].
Am I right? Is there a reason for this choice?
I’m trying to display forces (vectors in R^3) as animated arrows. My plan
is to attach a node to the tip of the arrow, and to translate it according
to the vector value.
In order to do this, I need to discard the orientation of the node, thus the
need for [0,0,0]-located vertices.
Here is a working (in OSG) example, illustrating this idea. The arrow is
a simple 2-vertices line.
http://gist.github.com/610049#file_skin_transl.dae
Here is a non-working one, where the vertex at [0,0,0] does not move.
http://gist.github.com/610049#file_skin … orking.dae
Maybe it would be simpler to scale and rotate the arrow. How would you do that?
Using matrix and scale? Or lookat and scale? Or rotate and scale (what happens
when the rotation axis is [0 0 0])?
Thank you for any insight.