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View Full Version : Do not tell OpenGL which will be render..?



Suvcon
11-17-2001, 08:15 PM
there is a large land,many object in or on it.Player just see a 5inchX5inch square in this land.
I wonder:if i tran all the land item to opengl and let it draw,the opengl can auto avoid rendering the unseen items and only deals with the item in the 5inchX5inch square.Does it right???
I write some codes to do the job,find which items is in the 5X5 square and trans them to openGL and let OpenGL render them.but i didn't get any profit.So i think,OpenGl can find the items in the 5X5 square to render and let the other unseen stuff pass by.
but,the land is so large and reading it into memory is a very waste.so the code to decide which items will be seen and read them.the code is necessary for the game as hl,myth...

maybe i am wrong,I put my ideas here and waiting you direct me with the word of "thanks" in mouth.

sorry,i from china and my english is not good as chinese.

T2k
11-18-2001, 01:22 AM
you have to filter all seen objects before passing them to opengl or you will get lower framerates, but if your filter-function is slow you will not gain any profit ... try to filter objects (check each object as sphere against the frustum-sphere) and let opengl filter the rest ...)

Lev
11-18-2001, 02:41 AM
as t2k said, you need to do frustum culling by yourself, but let opengl do the clipping. For terrain engines I would recommend octrees, quadtrees or kd-trees.

-Lev

Suvcon
11-18-2001, 02:56 AM
Thank you very much.
and now i get my mind clear.

and more:where can i read more about the "octrees, quadtrees or kd-trees" on line?

Bob
11-18-2001, 06:30 AM
Try this (http://www.google.com) place.