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View Full Version : Clipping planes: Looking for information.



4dartist
10-16-2007, 05:47 PM
I was wondering if anyone could explain to me or point me to documentation explaining how/why objects get clipped at a certain distance in LW in OpenGL. It isn't really something i HAVE to know, but it's always boggled me a little. I do lots of animations of rockets and flybys, often i find my objects/backgrounds/smoketrails getting clipped in openGL at great distances and it makes it difficult to work in the scene and create animatics with preview for clients because the background sphere gets clipped or other stuff. They usually render ok, but don't display in open GL.

And whats weird is, say my rocket is being clipped in the camera view because it is too far away but then i zoom in with the camera and i can see it again. *shrug*

Using [ and ] seem to help problems with the near clipping plane and sometimes it seems to effect the far clipping plane, but sometimes i get stuff clipping far off and no matter what i do with [ and ] the clip never moves. from 10mm to 1km of grid size.

I think i need to do some serious testing to see what exactly is going on at what distance, but i thought i would toss this out there to see if anyone can clear up this foggy subject for me.


Work arounds have been, make world null, make EVERYTHING child to it, and scale it down to like .1 .1 .1 and then my animation will fit in the scene. Unfortunately Hypervoxels will puke on you if you change the scale of the emitter. :(

or

fake the distance of an object by scaling it over time as it goes away from the camera thus looking like it's traveling further...

Just wondering.. Thanks!

clumsycloudy
10-17-2007, 03:11 AM
Hmmm, you did notice the grid changing when loading large stuff, lets say a starfield... Have you tried the fixed near clip distance in display settings? You could always rely on wireframe mode... ..opengl can be crappy in lw, even could be a graphic card issue.

regards ric