pfLightSource Frustum Culling Question

New Message Reply Date view Thread view Subject view Author view

Angus Dorbie (angus++at++division.demon.co.uk)
Tue, 10 Jan 1995 21:26:25 +0000

The performer manual states that when I use pfLightSources with no bounding
volume they won't be culled to a viewing frustum in the directed cull pass. I
interpreted this to mean that even if the pfLightSources were in scene graph
below nodes with a bound volume they wouldn't be culled if they had no volume
themselves. Unfortunately even if I explicitly set the bound volume of a light
source to be empty they still cull if a pfDCS node higher in the tree has a
dynamically updating bound volume. I've also tried adding an empty pfDCS above
the pfLight source as an experiment but this didn't help. The directed cull for
lights still seems to be prunning the tree.

I need my light sources to exist in the same hierarchy as my geometry but
without culling to my frustums. As an added complication I have a custom cull
callback which needs to return PFTRAV_PRUNE from some graph nodes and cull
pfLightSources below. This all works as expected appart from the frustum
culling of lights.

I'm using Performer 1.2 with IRIX 5.2 on various platforms.

My question is:

Do I have to separate the pfLightSources from my geometry graph to avoid
frustum pruning of lights (which means pfDCS duplication or matrix
concatenation overheads) or have I overlooked something?

Thanks in advance,

Angus.

-- 
_______________________________________________
 Angus Dorbie                Division Ltd,
 Software Engineer           19 Apex Court,
 Tel: (01454)615554          Woodlands,
 Fax: (01454)615532          Bristol BS12 4JT,
 angus++at++division.demon.co.uk  UK
_______________________________________________

New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:50:51 PDT

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.