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Re: Picking

On Wednesday, December 25, 2002, at 12:41 PM, Brian Greenstone wrote:
That's exactly what I've spend all day doing. I just finished it 3 minutes
ago and it works perfectly now. It's too bad that OpenGL doesn't have this
built in for a few reasons tho:

It's been a while since I looked at picking, but I don't see why you couldn't work around the min/max depth value by doing a glReadPixels on the depth buffer for the single pixel under the cursor to get the 'exact' transformed depth value. If you pass this into gluUnproject along with the screen x/y you should get pretty good results.

You will still probably get more precise results by computing the final point via ray/triangle intersection tests yourself (since the depth buffer is typically 'only' 24 bits has non-linear precision :). Dunno how much the precision matters to you, though.

-tim
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