View Full Version : display lists and the speed

06-13-2002, 06:32 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

06-13-2002, 06:58 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???

06-13-2002, 07:01 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 :-/


06-13-2002, 07:10 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.

06-13-2002, 07:41 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).]

06-13-2002, 07:51 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