STACX integrates itself as a channel shader into the material system of CINEMA 4D. As its name implies, STACX is working with layers in order to advance into the third dimension. You can stack up to 32 shaders and define a certain thickness for each layer. In this way you will get a three-dimensional material that you can use like a volume shader.
The idea for STACX came after a 3D project with wide landscapes. The memory usage for the textures was immense. The scene had to be divided into quadrants, in order to be able to use textures with lower resolutions for distant areas. Nevertheless, there were frequently appearing errors on some machines because of too little free RAM memory. Thus, STACX was originally designed as a terrain shader that creates varied landscape textures with a few relatively small bitmaps. While rendering, the shader accesses for each point on the surface the texture layer, that is responsible for the respective altitude.
For the transitions between the layers different functions can be defined. Possible are for example sine or triangle waves, or even an optional time-animated noise. In addition, the layers can be blended in a soft, adjustable range.
Three volume models are available for the orientation of the shader layers: cuboid, sphere and cylinder. Cuboids are suitable for all plane-oriented objects, such as a landscape model; the spherical model can be used for instance to figure a cutaway model of the globe in a simple way.
Demonstative examples can be found in the STACX video gallery.