LOD Terrain - Better to be small and many, or one big piece? -
11-30-2002, 10:00 AM
Im wondering if anyone has and stats/specs on the speed to the map (FPS that is) if you have one large LOD Terrain piece, or if you make it up with several smaller ones. I can see the advantages of both, but I'd hate to make it one way or the other and have it be slow as all heck. Thanks!
Either way will not affect Fps adversely at all as long as you delete unseen polys. The thing is to limit the open areas, where the engine has to render a lot of data at once. I personally build my terrain in patches, adjust them , and then snap them together.
Now there is a seamless terrain with no overlap (that is where it could slow down--when the engine is drawing layers of terrain instead of 1 solid piece).
See the thread "low FPS outdoors" at http://www.dafront.com/~nemesis. Vonderbaklufts answers will surely explain FPS in outdoor/terrain areas. And how to insert vis_leafgroups to limit what the engine will draw, thus increasing FPS.
well what i do with lod terrain is make a small section, edit it the way i want without touching the edges. then i make another small section and line up the edges with the first section and snap to stationary terrain and edit some more. and just keep repeating those steps. if you are making a map without a lot of lod terrain i feel this is the easiest way to edit it.
That is a very good way to do it. If you adjust your vertices first, and then snap the individual pieces toghether, you get a seamless final terrain that bypasses the vertex height restriction. It all depends on the layout of the map.
Proximity to LOD terrain causes large sections to be fully rendered. Deleting unseen vertices causes it's neighbors to be always rendered. The engine can only handle LOD if the elevation does not exceed 512 units per section and it doesn't matter if they are joined or not. You are getting a fair amount of mis-information here.
[quote:803c4]The engine can only handle LOD if the elevation does not exceed 512 units per section and it doesn't matter if they are joined or not.[/quote:803c4]
It does matter. If you take your 512x512 patch and adjust it's vertices to the heights you want, you can then do the same to another piece, and then snap them together for a total height DOUBLING the max restriction per patch. This process can be repeated to triple and quadruple the height restriction.
The key is to build the terrain in sections. If you join your 512x512 flat patches, and then adjust your vertex, then you are limited. So adjusting them first is the key. Then snap them together.
There is no misinformation here at all. Try it and see for yourself.
[img]http://www.msnusers.com/_Secure/0QwDeAikUC62ysmT4IR!A3Oj5CETGSPnMTpM5NA06mFcO*cY0U rv5htlC2s2dmDeTYUpdqstOL4yGcHW2kFrXvnBgq6UIpCLNvKl c0st0KeI/height.JPG?dc=4675399361776658818[/img]
You're absolutely right. But try snapping a grid of 16 LOD pieces together, and then adjust the vertices. Then tell me, even though the piece is 2048x2048, that you can get it higher than 512.
The way I built it, even if I went 512 high per section, I could have an elevation of 2048. You can't get that if you snap it first. You are then limited to 512 again.
You have shown 4 sections with a maximum elevation of 512 units. You could have done the same thing without joining them. Why do you think you have to join them? The maximum elevation per section is still 512 units, or 45 degrees. To exceed the limit you would have to show 3 sections of greater elevation. It's possible to have 2 sections exceed 45 degrees, so that doesn't count.