[Radiance-general] mixfunc for dichroic film?

[John An]

Hi all,

I have a somewhat complex problem defining a material.  With the 
introduction of "smart" materials (that are able to exhibit different 
behavior under different conditions) into the architectural context, 
I'd like to experiment with defining such a material.  The mixfunc 
material seems promising in that it allows one surface to display two 
different behaviors.  What I would like to achieve is to use an 
"if-then" condition to determine which of the two material properties 
should be exhibited in the rendering.  More specifically, I'd like to 
define two different behaviors (rgb, reflectance, and transmittance), 
and use mixfunc to determine which one of the two behaviors will be 
used for the rendering (on a each pixel) along the surface depending 
on,
1. the angle of the light ray from the point of view to the surface 
normal; and
2. the angle of the light ray from the light source to the surface 
normal

If this is possible, then would it be possible to eventually define 
more than two behaviors (by modifying a mixfunc with another mixfunc) 
to get a more gradual gradient between the different behaviors?

Thanks.


John An