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Package org.j3d.util.frustum

Generalised utility classes for all representing view frustum information.


Class Summary
ViewFrustum A utility for tracking the ViewFrustum planes and determining if a triangle or point is visible.

Package org.j3d.util.frustum Description

Generalised utility classes for all representing view frustum information.

The aim of this package is to provide an abstract representation of a view frustum for many different styles of application and algorithms.

The view frustum code uses features that are specific to Java3D 1.3 to access view projection matrix information.


The way the view frustum is implemented means that you will have a one frame delay between where your user code is at and where the view frustum is pointing. This is because it queries the Canvas3D and that query returns the projection matrix information for the last frame rendered, not the current settings. If you are doing jump cuts between locations, that can result in wildly inaccurate values.

To try to cope with some of these problems, a utility method is available to manually re-orientate the view frustum. The idea is that user code will move the viewpoint transformations, request the VWorld transformation matrix back and then apply that to the view frustum to give you a better idea of where the user is now going to be pointing in this frame. That should give more accurate results in the visual output over time.


The code in this package is based on the original work by Paul Byrne of Sun Microsystems.

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