This demo shows dynamic per-pixel lighting with shadows and proper shadow overlapping. The shadows are created by using the stencil buffer and Carmacks reversed algoritm.

Required OpenGL extensions:

This demo does self shadowing bumpmapping. Letting the bumps in the bumpmap cast shadows over the surface really adds a lot to the feeling of depth of bumpmaps. On the bad side of things is that it's not exactly for free, though not horribly expensive either. A horizon map is needed for every texture. The horizon map is a 3D texture of considerable size. For some textures you can get away with a fairly low res horizon map, for others you need a quite large one to get good results. For this demo I'm using one 256KB large horizon map and one 1MB large one for another texture. Performance quickly suffers if I use larger horizon maps.

For the sky I've written a shader that animates some kind of cloudy Quake-looking sky by using a 3D noise.

All shaders are written in HLSL.

The demo should run on Radeon 9500 and up and GeForce FX series.

2003-10-11:
Updated to include a menu item to let you toggle selfshadowing on and off.

Required Direct3D capabilities:

Normally shadowmapping uses only a single channel of the texture the scene is rendered to. Using that depth you can extract information about whether the current fragment is in shadow or not. However, this only works for opaque occluders. This demo extends the idea to work for transparent surfaces too, and makes transparent surfaces cast a projection of itself over the scene. To do this not only the depth is rendered to the texture, but also a color. Opaque surfaces renders white along with the depth, while transparent surface renders its color and leaves the depth unmodified. Then by simply multiplying the shadow factor contructed in a normal shadowmapping fashion with the color stored in the shadow map you'll get a nice projection of transparent surfaces over the scene.

The demo should works on Radeon 9500 and up and the GeForce FX.

Required Direct3D capabilities:

This is a demo that renders the scene to look as if it would have been sketched. This is done by finding edges in the picture. First the scene is rendered to a texture and the normals and the depth are outputted into it. Then a Sobel filter is applied to all components. This will highlight all edges, not only the silhouette against the background, but also internal edges where there's a difference in depth or when the normal changes a lot over a small distance. To get a smoother image, and to give it a fuzzy pencil drawn feeling, the edge value isn't thresholded, but instead I'm outputting the square of the Sobel filter to allow all kinds of shades of gray. Finally a slight blur filter is applied to smooth it out a little.

Should run on Radeon 9500+ and GFFX.

Required Direct3D capabilities: