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View Full Version : Is something wrong with this?



soconne
12-25-2003, 03:24 PM
I have a terrain that has about 9,000 triangles. I was recursively rendering the terrain since i stored it in a quad-tree like structure, so I decided to create a display list at startup and just call the list. Well before using the display list I got 130 fps, and now I only get 150 fps. I am only using 1 texture, with no lighting or fog of blending at all.

Here are my system specs:
P4 2.8 Ghz HT 800Mhz FBS
Radeon 9800 Pro 128MB

Something has got to be wrong. I've seen people render 32,000 triangles with a p3 450Mhz and get 150fps.

Does it matter how the data was rendered while creating the display list? I don't understand why it's not amazingly faster than this. Any ideas?

soconne
12-25-2003, 05:43 PM
Well i got it to run a lot faster.

without any textures or lighting, i get 750 fps with 32,000 triangles.

i get 275 fps with 90,000 triangles.

I then decided to add 1 texture and i got 650 fps.

But here's my second problem, when i perform multitexuring with only 2 textures the frame rate drops from 650fps with 32,000 triangles to 165fps. Is this normal? Should it be dropping this low?

JanHH
12-25-2003, 05:55 PM
what are you doing *g*

a) how did you manage to get it to run a lot faster? that could be a clue.

b) using a quad tree is absolutely pointless when you put the whole tree into one display list.

c) using one texture should be as fast as using no texturing at all. using multitexturing also should not cause a slowdown (if you are not using more textures than the number of texture units your graphics card has).

d) when all these things cause performance to slow down, the only thing I can imagine is memory swapping that occurs. very large display lists, very large textures.

e) or something completely different is going wrong.

regards,
Jan

soconne
12-25-2003, 06:38 PM
When I said i used a quadtree I meant when I was rendering it before because frustum culling is used this way. But I recursively go through the quadtree to simply submit each triangle to the display list, that's it. As for textures, I have 4 and each are 512x512. But I'm using a Radeon 9800 Pro, so this still should be fast as heck.

soconne
12-25-2003, 07:10 PM
Well this is really wierd. I binded 4 textures but didn't specify texture coords for units 1 - 3, only 0, and I got about 400fps. Even with 4 textures binded i get this. But as soon as I specify tex coords for the other 3 units it slows back down to under 90 fps.

Maybe I should contact ATI :-p