John Rohlf (jrohlf++at++tubes)
Wed, 24 Jan 96 17:10:03 PST
To avoid z-fighting, make sure you either have a local light
or are using a local pfLightModel. This is a RealityEngine
bug/feature.
> The man page mentions that a pfFrustum is required by the pfLightSource. That
> pfFrustum should tightly bracket the scene to be shadowed for best results.
>
> What is a nominal and non-transformed pfFrustum?
A nominal (or non-transformed) pfFrustum is one whose eye is at
the origin and whose view direction is the +Y axis. This is what
you get when you call pfNewFrust(). Once you transform a frustum,
either explicitly with pfOrthoXformFrust or implicitly with an SCS/DCS,
you no longer have a nominal pfFrustum.
Note that an SCS/DCS above a pfLightSource does *not* change its
pfFrustum, rather it transforms it so to move a pfLightSource
around, just stick it under a DCS and attach a nominal pfFrustum.
Just make sure that the FOV of the frustum is wide enough
to encompass those objects you which to shadow. But if you make
it too wide your shadows will get blocky.
> Since objects are moving, is it necessary to recompute the frustum every
> iteration?
No.
> Is the frustum from the light source point of view?
Yes.
This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:52:18 PDT