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mithun_daa
11-19-2003, 02:31 PM
i have a scene with a real heavy duty opengl list and another really simple one that doesnt need too many resources. i want to rotate the simple list while keepin the heavyduety list fixed. i m able to do that, but just because i have the heavy duty list in memory, even the simple list is very slow when its rotated. any suggestions to make it faster?

nexusone
11-19-2003, 06:45 PM
Buy a better video card!!!

guest
11-19-2003, 07:18 PM
If the heavy duty list does not move, then why not render it as a texture? Also, I will guess that the program is slower because you keep redrawing the heavy duty list even though it is not moving (I am assuming no transformations are being done on it). Is the heavy duty list transformation limited or fill rate limited?

mithun_daa
11-20-2003, 07:38 AM
Originally posted by Guest:
If the heavy duty list does not move, then why not render it as a texture? Also, I will guess that the program is slower because you keep redrawing the heavy duty list even though it is not moving (I am assuming no transformations are being done on it). Is the heavy duty list transformation limited or fill rate limited?

i dont know what "transformation limited or fill rate limited" means.
the only transformations done on the heavy duty list is that its being translated and rotated so that its at the origin.

guest
11-20-2003, 10:11 AM
Transformation limited generally means you have too many polygons which causes the geometry calculations to slow down the rendering the most. Fill rate limited means that too many pixels are being drawn that it is the main cause of slow down.

Example, rendering 1 million tiny triangles would be transformation limited. Rendering 10 Full screen quads (or triangles) would be fill rate limited.

If your program is transformation limited, draw less polygons and use textures instead. Otherwise, your polygons are too big and/or your drawing over the same region of the screen too many times (use culling).


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But to help you with your problem...

1. If you have lighting enabled but don't need it, then disable it (also make sure you do not enable more lights then you need).

2. Reduce the amount of geometry you have in the display list. Check the model you are putting in the display list to see if it really needs a high level of geometry.

The problem you have is common and the most common solution to it is to reduce geometry and use other features of OpenGL to simulate high geometry (such as texture maps).

Without knowing specifically what you are doing, I can't really give specific examples.

mithun_daa
11-20-2003, 11:53 AM
Originally posted by Guest:

Without knowing specifically what you are doing, I can't really give specific examples.

i have a terrain generated from a height map (.dem). i have provided a feature wherein, when u rotate the terrain, only a wireframe cube enclosing the terrain rotates, and when the desired angle is reached and the mouse button released, only then is the whole terrain rotated.
can u tell me more about how to make it a texture. is there any way i can just store whatever is draw on the screen as an image?

thank u