- When do we clip in 3D? We should clip to the near plane
*before*we project. Otherwise, we might map*z*to 0 and then*x*/*z*and*y*/*z*are undefined. - We could clip to all 6 sides of the truncated viewing pyramid. But the plane equations are simpler if we clip after projection, because all sides of volume are parallel to coordinate plane.
- Clipping to a plane in 3D is identical to clipping to a line in 2D.
- We can also clip in homogenous coordinates.

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Readings: Red Book, 6.6.4;
White book, 6.5.4.
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CS488/688: Introduction to Interactive Computer Graphics

University of Waterloo

Computer Graphics Lab