It's dubbed the Variance Shadow Maps Demo (D3D10), and, unsurprisingly, it demonstrates variance shadow maps under Direct3D 10. It's programmed by a chap called AndyTX, and it looks pretty funky in action.
You can open it up and play with a bunch of the different variables to get different shadow effects, and there is plenty of techy documentation in case you want to understand exactly how this works. Apparently, "int32 is also really awesome for summed-area tables" and "the splits are rendered into a texture array and the applicable split is computed in the fragment shader when shading the scene". Obviously.
The demo appears to be part of the GPU Gems 3, the latest graphics programming handbook to come out Nvidia, and the source will be included in that. To get it up and running you'll need Vista, a DX10 card, the latest DX10 redistributable and the latest Visual C++ package. Check it out, and let us know if it knocks your little LCD socks off.
Please note the requirements (as detailed in the included Readme):
- Any reasonably modern CPU/RAM
- Windows Vista (for D3D10)
- A D3D10 capable video card
- DirectX Redist April 2007
Available free from http://www.microsoft.com (search for the above) - Visual C++ 2005 Redistributable Package
Available free from http://www.microsoft.com (search for the above)
Some screenshots:
SAVSM:
PSVSM:
Note that this quality level is greatly superior to stock PSSM/CSM, even when the latter have much larger shadow maps and more splits. Check out the PSSM demos if you don't believe me.
PSVSM Splits:
Zoom in and note that pixel quad trick at work.
VSM for the same scene:
Note how much poorer it looks compared to the above - the effect is even more pronounced in motion, and for lower resolution shadow maps.
