[Radiance-general] defining structured (textured) surfaces in radiance?

[Lars O. Grobe]

Hi list!

Once again a question about texturing a surface. In radiance, I know 
about two ways putting color modification (pattern) or / and normal 
modification (texture) on a surface to achieve a structured appearance. 
Besides, brdf-modifiers allow to implement the reflection effects of 
more complicated surfaces.

However, if I have surfaces with effects caused by their 
(micro-)structure, I get into difficulties. Radiance does not have 
something like displacement maps, so the effects from geometry can only 
be achieved by modeling the surface. I have been thinking a while about 
how to get the appearance of a mosaic for example, which conists of a 
layer of gold, a piece of glass in front of it, and which has it's 
effect when seen from a distance because of the specular reflections, 
the different layers and the irregularities in the overall surface. 
Another example might be the well-known tennis-ball, which can be 
rendered in radiance only by entering the geometries as instances. 
However, this example hass afaik less complicated reflection 
properties, e.g. the specular reflection is not that important. There 
are other known examples for textures with important geometric details, 
of course, e.g. textiles.

Is there a way now to apply a geometry (in the radiance software 
handled like an instance for memory effectiveness) as a texture? It 
would be much more convenient to apply such a 3d-texture by using the 
tex-modifiers to an existing surface than writing scripts to place 
these instances following an imaginary surface. Did anybody think about 
doing something like that with radiance, or are there reasons why one 
should not even try that?

CU, Lars.
--
Lars O. Grobe
grobe@gmx.net


--
Lars O. Grobe, grobe@gmx.net, ++90-212-2458330

Kardesler Apartment, Turnacibasi Sokak 28
Galatasaray - Beyoglu, 34433 Istanbul