Hello there.
I am converting an old 3d cinematics engine from sandy3d to away 3d.
In my engine, actors are made from different meshes, placed in a bone hierarchy. All the meshes from one actor shared the same material; a bitmapData where all textures were drawn.
Face expressions were drawn from a movieclip into the bitmapData, and there were quite a lot of different ones.
Sandy3d used the texture as a reference when creating each triangle fill, so to change expressions I would only need to redraw on the bitmapData.
Away3d uses the GPU buffered system, this means the usual way to animate a texture is to have it’s frames in a 4x4 matrix (or 8x8 or similar) and draw only the section required. This method will become troublesome, because I have more than 16 expressions, and I don’t want to build a too big bitmapData to hold all the possibilities.
What options do I have?
1-draw on the bitmapData and reassign it to the material in each change of expression?
2-separate the face in a smaller bitmapData, and draw on it, reassigning it to the material- same as before, but with a smaller texture?
3-limit my expressions to a sizeable matrix of 4x4, separate the face in a bitmapdata texture with these 16 expressions drawn, and animate it with the standard method?
4- is there another method that I don’t know of?

Many thanks.