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View Full Version : BVH: Help with concatenating local transforms...


eek
09-09-2009, 07:52 PM
Im trying to understand this line from a document about BVH parsing:



Adding the offset information is simple, just poke the X,Y and Z translation data into into the proper locations of the matrix. Once the local transformation is created then concatenate it with the local transformation of its parent, then its grand parent, and so on.

vM = vMchildMparentMgrandparent…

Taken from http://www.cs.wisc.edu/graphics/Courses/cs-838-1999/Jeff/BVH.html


Does this mean for every recurve parent get its local transform, and multiply them together, with the rotation from the BVH?

PEN
09-09-2009, 08:11 PM
Sounds like it as I think that each of the values is in world space from what I remember.

eek
09-09-2009, 08:18 PM
Sounds like it as I think that each of the values is in world space from what I remember.

I think what happens is that your building a transform from its local parents transforms. eg.

theRotationMatrix

the parents
a.parent = b.parent = c

which means theRotationMatrix * (a.local transform) * (b.local.transform) * c

something like this, as basically we building a transform thats relative to the joints, great great great etc parent (its final parent) i think

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09-09-2009, 08:19 PM
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