[Radiance-general] Metal Reflection Problem

[Carsten Bauer]

Hi Marcus,

in pic room1_default5a you probably miss the reflection of the big 
light-source rectangle on the floor. This is the classical backward ray 
tracing problem, with photon-map things would look differently.

concerning the metal reflections:  high jittering parameters can be 
tricky, a good way to find out what's happening is to start with very 
low settings for both material and rendering params (i.e. almost smooth, 
polished surfaces and the default -dj -dc -dt -sj -st vals) and raise 
them in little steps subsequently to grasp the point when the modelling 
differs from the expectations.

the latter should not be too high, either, many special surface 
properties of custom materials can not be modeled adequately with the 
standard Radiance models. This is understandable as things become really 
difficult when looking at the details. sometimes it helps to add an 
extra normal perturbing texture modifier to the specification, as one 
often has to deal with "roughness structures" which are too big to fit 
into the microscopic roughness models employed by plastic(2)/metal(2) 
materials

-cb