[Algorithms] normals in skeletal animation

[Vladimir K. <vka...@si...>]

Hi,

How to handle normals in skeletal animation?

Currently I use this way :
After loading model I take first frame and calculate all normals.
Then I use inverted bone matrices to transform normals into
some 'pretransformed' state and store it same as offset vectors
(every vertex has list of pre normals for affected bones)

At rendering time for every affected bone I transform this
normals using current bone matrix, multiply to the weight, sum it
and normalize.

In result I get something hm.. :)
In most cases it looks ok but sometimes it looks like some normals
was calculated using incorrect bones.

In any case I think should be much better way for this.
Can anybody recommend something?

Thanks
vlad