In PS, I want to get a ray in view space to do volume rendering.
Let's say I have the camera position in the view space. I want to get the other end of the ray corresponding with the screen position. So I can define the ray.
My question is how to convert the screen position to view space in PS?
The camera position in view space ? It is the origin : float3(0,0,0) :)
The viewspace ray can be determine from the screen coordinate normalize to -1..1, add a fake z that represent something like the far plane (value depends on the kind of projection you use), w set to 1 and multiply by the inverse projection. Divide the result by w, normalize the float3, and you have your viewdirection
