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steg

terrain

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Hi all, Having done a brute force terrain I am now looking at applying some optimizations to it. There seems to be quite a few ways of doing this : CLOD ROAM QUAD TREES I guess I should implement CLOD first and some culling ? Your thoughts would be appreciated, Steve

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I would go with octrees first personally, it''s not to hard to learn to implement, and if you do implement them, your implementation of CLOD would have to change to suit your quadtree rendering function. If however you implement your octree system first, your CLOD system would only need coding once.

I''ve personally not used ROAM, so perhaps someone else more knowledgable on the subject could guide you there.

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Thanks,

I''m thinking of using quadtrees with CLOD. First off though, my brute force is using triangle lists, so this is a defo no no, take it I''m better to use either index buffers or triangle strips ?

Steve

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Personally I would stay far away from CLOD because it is very CPU intensive. I suggest using Quadtrees or Octrees in combination with geomipmapping. They go very much hand-in-hand. Go to www.andyc.org click on #lectures and read the log on "the future of terrain rendering". It''s excellent!

Sander Maréchal
[Lone Wolves GD][RoboBlast][Articles][GD Emporium][Webdesign][E-mail]

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Quadtrees are overhyped. They mesh well with geomipmapping, but too often they are used with constant-LOD terrains for culling, which I wouldn''t recommend. Just project your fustrum on the ground plane and scan-convert the tiles. It makes for fast, accurate, tight, fustrum culling.

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Thanks guys,

Seems many of you use differing techniques. I''m thinking of using quadtrees with geomipmapping, seems quite nice. Would you still not use CLOD with this though ?

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The scan-conversion technique seems all well and good, but how well does it scale to really massive terrains? It seems that you are going to need some kind of hierarchical data structure for a massive terrain, and a quadtree is a good choice. What you could do is make each node in the quadtree a large block of tiles, and scan convert them. So the quadtree would be used for culling on the kilometer scale and above for example, then the nodes simply scan-converted.

I''ve read that the UT engine now uses a brute-force scan-conversion method, but then again their terrains aren''t very big.

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