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ugluk
08-04-2010, 05:13 AM
I have a heightfield that is of power 2 width and height. Height and width are the same. For higher LoDs I render all the triangles in the hf, but for lower LoDs I skip every 2nd, 4th, ... vertex.

The problem is that all the normals of the hf mesh are computed for the highest LoD, not the lowest LoD. What are the approaches to solve this situation? Do I need to recalculate the normals for each of the LoD levels, or maybe do something else? Are there algorithms to simplify the normals along with the triangle mesh?

I fear the entire thing is going to be very complicated. I've read of people calculating normal maps to simplify the geometry, but retain the quality of the rendered image.

remdul
08-04-2010, 08:31 AM
I would suggest baking the lighting into a texture, or if you need dynamic lighting, use a world space normal map. Use this for all LODs. It significantly reduces 'popping' when switching between LODs and generally looks better on the lower LOD levels.

Personally, I would not even consider lower LODs having their own set of normals. It wastes memory, be of lower quality, visible popping between LODs etc. I can't think of any advantages.

ugluk
08-05-2010, 04:44 AM
With a "world space normal map" you mean a megatexture, if the world is very large?