From: owner-3dui@hitl.washington.edu on behalf of lpastrana@altern.org
Sent: Friday, August 18, 2000 6:36 AM
To: 3d-ui@hitl.washington.edu
Subject: Re: Far clipping planes

>I'm actually hoping for multiple answers here, folks, so please take 2
>minutes and check where your 3D authoring tool puts the far clipping plane.

>On our end, Alice puts the far clipping plane at 256 meters by default.

>Jeff

Hi jeff i guess there could be a bilion answers to your question this way... but i believe what determines your Z-clipping planes is the bitdepht of the z buffer on the implementation side; is it 16, 24 or 32 bits, i mean bit depth of your z buffer is THE constant...

in fact the first answer to your question 

>I have found that the diagonal of the bounding box for the "universe" times
>a fudge factor (1.05) works well. 

was the most "exact" technically... to be more precise, what you need to determine to set the far clipping plane is : 
1: what is the longest distance you want to be able to manage ?
2: what is the precision/scale/unit you need for the z values in your scene ?
3: does that fit into your 16, 24 or 32 bits z buffer ?

Hope that helps.

Lorenzo Pastrana.