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From: tkessells01@cc.curtin.edu.au
Newsgroups: comp.graphics
Subject: Triangle/Box intersections
Message-ID: <1991May9.144308.8054@cc.curtin.edu.au>
Date: 9 May 91 06:43:07 GMT
Organization: Curtin University of Technology
Lines: 28


What is needed is a fast triangle/box test. I don't need to know the 
intersections, only whether they hit each other.

Currently, I 'm doing :

pre-1)	usual bounding extent tests, etc ...

1)	check if whether the box is completely above or below the plane
	fitting the triangle.

2)	check if an edge of the triangle intersects the box.

3)	check if an edge of the box intersects the triangle.

I have fiddled the order of doing these tests with little change in speed.
The reason a very fast test is needed, beause I am converting triangulations
into blocked representations where there is a higher resolution near the
triangles and grids of 400x400x400 are not uncommon.

Any code, ideas or complete solutions would be appreciated

	Michael

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