In an AGAL Vertex Shader, what is the 'w' component used for in the output shader?

Question

I understand the 'xyz' components of a vertex's position, but what does 'w' do? Could it be left as the same constant value all the time?

Example:

mov op.xyz, va0.xyz
mov op.w vc0.w

Answer 1

I'm not familiar with flash, but it seems that you are dealing with homogeneous coordinates . If you are only dealing with vertices, it should be fine to leave it as 1.