Hello everyone i have a self shadowing problem using shadow maps the shadows work just fine except some spots which look like in the picture below www.baltzstudios.com/artifact.jpg does anyone know whats wrong and how to fix it ? :P i am using a simple version of shadow mapping

thats quite normal, try to increase the z bias and maybe add a little offset when comparing the shadow depth buffer with your scene depth buffer (very small). maybe you have also a percision problem, try using a greater bit depth (32 bit instead of 8 or 16 bit).

shadow mapping is a lot of tweaking, especially if you don't have high percision formats available.

Quote: Original post by Baltz
Hello everyone

i have a self shadowing problem using shadow maps

the shadows work just fine except some spots which look like in the picture below


www.baltzstudios.com/artifact.jpg


does anyone know whats wrong and how to fix it ? :P

i am using a simple version of shadow mapping

If the object is closed, render only its backfaces (backfaces to the light source of course).
Try some bias too, especially good if your shadowmap depth isn't dependant on perspective (then bias can be constant across the scene).
Try PCF. Then try VSM. :)

I have been playing with the zbias the last couple of days almost as much as i have with my willy... :P

i guess i will have to move on to techniques such as VSM or PCF

thx for the ideas gyes