Another dumb question regarding shaders, but meh.

I already do calculate a depthmap for use in a depth of field post processing shader. Now, I wanna use the same depthmap in a terrain shader to allow some kind of dynamic lod system. What I basicly wanna do is blending out detail maps depending on the distance to the camera. I however do not wanna use lod techniques, because I want to have different lod stages for a single model/terrain.

But in general, can I use a processed bitmap, as the depthmap, in an object shader?

I don't see why you shouldn't be able to do this. You just have to define a sampler with the depthmap as a texture. You should however keep in mind that the depthmap is then from the previous frame.

However, I think it would be easier to transform the objects vertices in a vertex shader to camera space. You then already have the depth of the objects vertices in their z coordinate. Compared to the depthmap solution you have up to date data and don't need to do the texture lookup. So the depthmap solution is something like a detour for something you need to do anyways in a vertex shader.

Ahh, of course, why didnt I see this.. all I got to do is re-calculating the depth in the vertex shader, of course, thank you. It's so easy...