Hi, I have been testing the effects of translating a scene (including
viewpoints and lights in the local scene) away from the origin.

When I get to around 1million units, spheres get truncated in a strange way:
they are drawn either hemispherical or quarter spherical. Looking at
Spheres.cpp gives me no clue as to the cause - nothing obvious.

The truncation is not z buffer clipping or due to other objects in the scene
(a plane) as far as I can determine. I suspect that the displacement is
introducing enough error into the program that some part of the
calculations do not render some quarters of the spheres.

Anyone have insight into the actual part of the calculation that is failing?

Image and pov file are here:

http://www.planet-earth.org/SpheresStressTest1Mil.pov
http://www.planet-earth.org/SpheresStressTest1Mil.jpg

Post a reply to this message