Re: No geometry on the scene..

Jim Helman (jimh++at++surreal)
Thu, 27 Oct 94 13:38:00 -0700

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Unless a static bounding volume prevents upwards propagation
in the scene garph, the change of a child bsphere causes the
lazy recomputation of all bounding spheres of its ancestors
up to and including the pfScene.

For this reason, flat hierarchies are bad for performance. In
particular, a pfScene with 100 children will be an expensive update,
since when anything changes anywhere in the scene graph, all 100 child
bspheres of the scene must be unioned with pfSphereAroundSpheres.
It's also bad for culling performance, since typically all 100
child bspheres have to be cull tested when the parent is partially in
the viewing frustum. Use hierarchy!

rgds,

-jim helman

jimh++at++surreal.asd.sgi.com
415/390-1151

• Next message: Andrew Pickering: "Unsubscribe"
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