Crepuscular Rays
Ah yes, crepuscular rays [ no relation to fatty corpuscle ], or 'god rays', or 'sweeet sweet light shafts', take your pick...whatever you call them, they're badass :-)
Crep. Rays are to the bloom effect, what the bloom was to the lens flare :-o
Here is an image from Wiki...incase you don't know what the hell I'm talking about.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Crepuscular_rays_in_ggp_2.jpg/800px-Crepuscular_rays_in_ggp_2.jpg)
So yea, there we have it.
My implementation is based off the article in GPU Gems 3. I read the article a while ago, but saw a youtube video when I was designing my GPU particle system, and the dude was demonstrating various post processing effects in his particle engine. I was instantly taken by the effect, seeing it in motion.
I sent the dude a message and he got right back to me, and I had it ingame in no time, it dropped right into my existing HDR pipeline a little too easily lol.
">Here is the video that inspired me [ the crep. rays are like at the end of the video, it's an interesting watch though ]
I'll have another update in a day or less with -
- 3 More tree types added into the environment [there's just one now]
- Heavy dynamic instanced grass / tall grass patches
- Updated crepuscular rays
- Mayyyybe some gameplay
Without further here are some screenshots of the effect :-D
55 Samples per pixel :-o One of the first images after I got the effect into my pipeline. I use MRTs to output to a postprocessing texture the size of the screen. I'm poised to implemented motion blur an depth-of-field into this game...but it might be overkill combined with the HDR/Bloom/Crep.Rays lol.
![](http://www.radioactive-software.com/images/Crepuscular_Rays2.jpg)
![](http://www.radioactive-software.com/images/Crepuscular_Rays3.jpg)
After more tweaking...
![](http://www.radioactive-software.com/images/Crepuscular_Rays_Composite1.jpg)
Until tomorrow or the next day, peace.
- Danny