Problems w/ Dynamic Shadowing

I’m trying to generate shadows - using sample from OpenGL super bible - and am getting strange rendering artifacts on the backside/shadow side of my scene. The front.jpg and back.jpg file located @ http://rastar.merseine.nu/~hall_monty/ illustrate this. I’ll post code upon request, but I suspect it’s some type of texture parameter that impacts resolution. The backside looks “voxelated”.

The technique used in the book:

  1. Creates a 3d depth texture from the light’s point of view
  2. Draw the scene in low lights(shadow) from the user/camera view.
  3. Draws the scene in high lights(light on) but uses the rotated 3d texture into user/camera view as a stencil. I mean a stencil in effect and not in fact, that is no writes to stencil buffer.

This technique seems a little different from what I’ve seen where the user need to calculate shadow, this brute force calculates and applies texture. Any how, if anybody can recommend a fix or have a working example using the approach above (not from nehe), would appreciate.

Regards,

Monty

That’s shadow acne. You may try to apply an offset to the polygons z-values when rendering the depth map.