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NOTE: This Technical Q&A has been retired. Please see the Technical Q&As page for current documentation.

Clarification of TQ3HitData's 'distance' Field

Q: TQ3HitData's "distance" field is described for window-point picking as "the distance from window point's location on the camera frustrum (in world space) to the point of intersection with the picked object." Does this refer to the (center) of the intersection of the pixel's frustrum with the hither plane, or maybe the yon plane, or could it be the camera location?

A: TQ3HitData's "distance" field is the world space distance from the origin of the picking ray to the intersection point. Effectively, this is the distance from the camera to the intersection point in world coordinates.

[Apr 08 1996]

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