Mehran Hoodeh, 3D Raster
  What is 3D Raster Format ?
Raster (Satellite) images usually contain the average color of a prtion of the terrain. (X,Y,color)
The images are always a 2D image.
If we assign a Z-value (height) of the pixels' coordinate to them we will then get a 3D raster whose pixels are in an (X,Y,Z,color)
Now, if you can do a PutPixel command in 3D, you will simply get a 3D-Raster.

The advantages can be:
- Easy to make (no complex algorithm on Z interpolation)
- Easy to draw (no sophisticated 3D Engines needed, just a simple PutPixel_3D(x,y,z,color) function suffices)
- Easy to store (any custom file format can be used) 

The disadvantage would be:
- On zooming too much into such a drawing, the pixels would start separating and grains would show up. (This can have a simple remedy: making more pixels out of the existing ones by increasing the image size.)
- Its drawing is rather a CPU consuming than a GPU-dependent one.

  3D Raster sample  
  Mehran Hoodeh, 3D Raster