Jump to content
  • Advertisement
Sign in to follow this  
jpventoso

UltraShadow on ATI?

This topic is 3633 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hello everybody, Yesterday I implemented Hardware Shadow Mapping (taking advantage of the nVidia's UltraShadow technology) on my 3D engine. Luckily it was easier than I expected :) I tested on my GeForce 6800 and it ran ok. But today I decided to try it on an ATI 2400+, hoping that the engine would automatically switch to standard Shadow Mapping (I use CheckDeviceFormat), and for my surprise, the engine started with Hardware Shadow Mapping enabled! So I went into debug mode, and I found that the ATI device allowed the use of a DEPTHSTENCIL usage texture with D24S8 format. Plus, I found that the intrinsic tex2Dproj returned the depth comparison as nVidia does! Is this normal? I thought that UltraShadow technology was a patent of nVidia. Did somebody have the same experience? Thanks in advance!

Share this post


Link to post
Share on other sites
Advertisement
UltraShadow technology is for accelerating stencil shadow volumes, not shadow maps. The NVIDIA shadow map feature you are most likely referring to is PCF (Percentage Closer Filtering). PCF is implemented in several ATI cards, for example in the 2400+ card that you have.

Share this post


Link to post
Share on other sites
Oh, thanks for the answer, my mistake then... That's good news! So I ended up implementing a feature that goes beyond nVidia, without knowing that!
Well, thanks again! You made my day :)

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!