[Radiance-general] Modulating diffuse albedo by an image

[Claus B. Madsen]

Dear List members,


I have written a function file which allows me to project real images
taken with a calibrated camera onto the (manually) modelled geometry of
the scene (see attached images). Writing the function file was dead
simple thanks to the really powerfull and well-designed function file
framework.

I have used colorpict to modify a plastic material with parameters (1 1
1 0 0), i.e. a perfect diffuse reflector. My function file tells
colorpict what uv coordinates to use for a given ray.

My question/problem is: how to handle the ray intersection points that
do not map to a pixel in the back projected image (i.e., points that are
outside the field-of-view of the original image). The attached image
clearly shows how the top and bottom image lines, and left and right
image columns get smeared across the geometry because I am computing uv
coordinates which in fact are outside the image bounds.

What I really want is to be able to return a controlled (constant) RGB
value for all uv coords falling outside the image bounds.

Suggestions, anyone?

Best,
Claus





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