HDR lens flare

jingquan · Post by **jingquan** » Sun Feb 03, 2008 4:38 am

Does anyone have an idea of how to create ghosting effects around the bright areas of the scene as part of HDR postprocessing. I have thought of using the bright-filtered image to locate the ghosting spots, but how can I apply it and change it according to view?

Any articles would help too. Thanks.

dlangdev · Post by **dlangdev** » Sun Feb 03, 2008 9:37 am

see:

http://safari.oreilly.com/9780321545404/ch29lev1sec8

jingquan · Post by **jingquan** » Mon Feb 04, 2008 2:19 am

Thanks, but is there any other free alternatives?

dlangdev · Post by **dlangdev** » Mon Feb 04, 2008 2:27 am

i think you can code it, though.

check if sun is in the viewing volume, then project a ray from it to the camera, you should be able to stick a billboard that looks like a flare.

jingquan · Post by **jingquan** » Mon Feb 04, 2008 9:06 am

Thanks. I've done tried similar sprite based. Although it works the results weren't really that nice. I'm looking for a true HDR based version of ghosting. Also, I'll need all of the intensly lit spots to have this feature, not just the sun.

This has awe-inspiring ghosting: http://www.daionet.gr.jp/~masa/rthdribl/

I'll see if I can find more info on the web.

jingquan · Post by **jingquan** » Wed Feb 06, 2008 5:52 am

Ah, I see they scale the brightpassed image at the center:

Code: Select all

Out.texCoord1 = (texCoord-0.5)*(-2.0) + 0.5;

But I kept getting a repeat of the image if I downscaled it. How can I prevent this?