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View Full Version : How to implement smooth ZOOM???



immy
05-06-2002, 07:28 PM
Hi
I implemented zoom in & zoom out in my terrain engine but since the fps is low so its looks jerkey & slow.
I want it the zoom function to be smooth. any suggestions. Hoping for nice replies
Bye http://www.opengl.org/discussion_boards/ubb/smile.gif

Zeno
05-06-2002, 08:39 PM
If you want a smooth zoom with a slow framerate, you'll have to either zoom very gradually or find some way to increase your framerate. No other options here.

-- Zeno

billy
05-06-2002, 11:27 PM
If you want to increase frame rate, I think you need to decrease the detail of the scene while zooming. Render only what you can see.

immy
05-07-2002, 01:57 AM
Originally posted by billy:

If you want to increase frame rate, I think you need to decrease the detail of the scene while zooming. Render only what you can see.



Hi
Thanks billy thats a nice idea but am using display lists so can't change whatever is displayed http://www.opengl.org/discussion_boards/ubb/frown.gif

LordKronos
05-07-2002, 02:22 AM
Originally posted by immy:
thats a nice idea but am using display lists so can't change whatever is displayed

Sure you can. Just break up your large display lists into several smaller ones and organize them well so that you can effectively cull whole lists at a time.

For LOD, either create multiple display lists for each LOD, or have a single display list for the highest LOD and then manually draw the lower ones using arrays. Or just completely drop the display lists together and use indexed arrays (probably the best option).

Never say you cant do something one way because you are already doing it another way (its kinda like saying you cant start eating healthy because you are already fat from eating junk food). If the other way has problems that you cant solve, its probably a flawed technique and is in need of being replaced anyway.

billy
05-07-2002, 05:41 AM
Immy, do you use some kind of optimisation like bsp trees or octrees?

I think you should do some research on this. Unfortunately I can't help you.