Quote from: Themodman101 on June 07, 2012, 12:32:20 AM
EDIT:
1) Ahhhh okay guys, I didn't know that I needed both a compute normal and a compute terrain leading into the Distribution shader.
2) Now I'm wondering something else. is there a special order that you have to do things in to get good results with DEM without loosing the shapes that are there naturally? Cause anytime I add detail it seems I loose the subtle shapes that make up the DEM. and it also creates nasty artifacts.
I attached an image to show what I mean.
1) No, that's not true. Like Ulco (Dune) said you'd need to have a compute normal before the terrain fractal in an order like:
Heightfield Shader -> Compute normal -> Fractal Terrain (blended by distribution) -> more displacements -> compute terrain -> shade/texture.
The reason for a compute normal before the fractal terrain is because it will provide the data-stream from the heightfield to the fractal terrain shader with the calculated normals of the heightfield. Since selection by slope is based on the direction the faces are facing, i.e. the normals, you only need to compute those.
For altitude restriction you'd need texture space to be calculated. You can do this separately with a "TEX coords from XYZ" node.
However, a "compute terrain" node does BOTH normals and texture space.
2) See above answer for the most easy way to understand how it works. At a later/advanced stage you can use compute nodes throughout all the network, but seldom that's necessary and like I said only necessary when doing complicated stuff.
I'd suggest you disable fractal detail in the heightfield shader (red one). You'll get a supersmooth heightfield which you can precisely tweak with fractals. Often the enrichment of the heightfield shader by the fractal detail function can get in the way with other things, like fine displacements or fake stones etc.