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Phobeus
06-13-2002, 05:32 AM
Hi Guys, i am working with OpenGL for some month know, and currently try to learn some methods to speed up programms. So however I land at the display lists and thought I would have realized how to use them.

However everything is working quite nice, no speed drop or something like that, like some are writting frequently, in fact, i cannot see any speed gain. If I use thousand of objects with using display lists or not, i always getting the same speed.

So my question: Are display list still up to date or are they somekind if relict of ancient times? I currently working on a P4 with 1,7 Ghz and a Geforce2MX with a system full of RAM (shall be ideal for display lists right?)

Thanxs for answers http://www.opengl.org/discussion_boards/ubb/wink.gif
Sincerly,
Phobeus

GameMaker
06-13-2002, 05:58 AM
You can use display lists for static data that doesn't animate and it is very fast. I hear vertex arrays are about the same speed too. As for your frame rate not changing...Can you draw the model hundreds of times in a loop with no slowdown???

Phobeus
06-13-2002, 06:01 AM
In fact I used vertex arrays also in the test and even have the feeling that they are the most best way to get data fast on the screen.

When I drawing static data in a loop, of course the FPS goes down also, but it seems to me like there not much difference between using a display list or normal rendering.

Or does it really is usefull, when using complex models? I used for testing a textured cube and let several hundreds of them rotating on the screen :-/

thx,
Phobeus

zen
06-13-2002, 06:10 AM
According to the red book,for small lists(models) the list callinf overhead might make them not worth the while.So you propably need some more complex objects to see any difference.

yakuza
06-13-2002, 06:41 AM
I did a similar experiment with 1000 cubes, with a keypress to alternate between display list and immediate mode. I noticed no change in speed with this scenario.

However, when I put the rendering code for a good sized .3ds model into a display list, my framerate tripled! (from ~30 to ~90 fps)

So you definitely need complex objects to take advantage of the speed increase of display lists.

[This message has been edited by yakuza (edited 06-13-2002).]

Phobeus
06-13-2002, 06:51 AM
Okay, thanks for the answers. I will test it out then with some more complex objects http://www.opengl.org/discussion_boards/ubb/smile.gif

Thanks!
Phobeus