   Terrain creation, texturing and rendering
  This may sound like a content creation question, but it actually relates to programming as well:Are there any tools for creating terrains that support overhangs and caves, and for texturing a terrain by "painting" textures onto a terrain using a palette of available textures which can be applied to polys on the terrain?And then an LOD algorithm that works with terrain created by these tools?Lots of code out there shows how to do different terrain implementations such as CLOD, ROAM, GeoMipmapping, etc. but few people address the problem of terrain creation tools. I''m not just talking about the tools out there that take heightmaps and create a terrain, automatically putting snow in the highest areas and water in the lowest areas. I''m talking about having artists really be able to create terrains as they want them (overhangs, caves, steep hills, etc), and apply textures to the terrains as they want.3ds Max can be used for creating terrain meshes that have overhangs and caves. Is there any source code out there that can take meshes exported from 3ds Max, possibly in segments, and then render them using LOD? There are ways to do this using a heightfield with overhangs being seperate meshes and caves being holes in the terrain with a mesh placed in the hole, but this approach is difficult to do so that the terrain the cave match up properly. Also, heightfields cause stretching when the terrain is very steep. It would be nice to allow artists to create just about whatever they want for the terrain, without the limitations of having no overhangs, no caves, no steep hills, and no real control over the textures that are applied to the terrain.And then there''s the problem of texturing the terrain. I would prefer to be able to use the "texture splatting" technique described here http://www.cbloom.com/3d/techdocs/splatting.txt to texture the terrain. This would allow an artist to basically paint whatever textures they wanted onto the terrain. Put some rocks over there, put some dirt here, blend them together, etc. The problem is that, as far as I know, there aren''t any programs out there let you simply apply textures to quads on the terrain, and support blending between textures. I don''t like the technique of stretching a texture over the terrain and then use a detail texture which tiles over the terrain to add detail. Any suggestions, comments or criticisms?Clay 
  Look at this site :http://www.vterrain.org/index.html(how to make text an URL ?)... or wait the terrain engine and editor I''m working on I''ve been studying terrain for almost 1 year and I dont remember to have seen a tool/method for caves... ;  If you look at the NeL engine (http://nevrax.org), you will see that they have accomplished overhangs and caves by using beizer patches for the terrain, and having the terrain be modeled in a modeling package, rather than the engine interpreting a heightmap.   [edited by - MikeMJH on February 4, 2004 10:20:12 AM]