[Radiance-general] Rendering a normal map with RADIANCE

[John Mardaljevic]

Claus,

> I need it for importing the per-pixel normals into a program I am
> writing myself, which will estimate the scene illumination conditions
> from an image of a scene. I have a 3D model of the scene, I know the
> camera position and orientation relative to the scene, and from the
> camera I get the "measured reflected radiances". Given the per-pixel
> normal information I have developed a method for estimating the
> illumination conditions in the scene ... makes sense?


Well, perhaps if you're going to do something 'fancy' (but no if you  
just want the illuminance).  As suggested, a command like this:

vwrays -ff scene.pic | rtrace -h -w -fff -on scene.oct > norm.dat

will write out a binary file of the normal at intersection for each  
pixel.

I'll own up to being intrigued.  The derivation of the "illumination  
conditions" at the pixel will be confounded by any deviation that the  
scene materials have from pure diffuse reflector.  In any case,  
you'll need to know what those diffuse reflectances are on a per  
pixel basis.  Can you expand a little on your method?

-John

-----------------------------------------------
Dr. John Mardaljevic
Senior Research Fellow
Institute of Energy and Sustainable Development
De Montfort University
The Gateway
Leicester
LE1 9BH, UK
+44 (0) 116 257 7972
+44 (0) 116 257 7981 (fax)

jm at dmu.ac.uk
http://www.iesd.dmu.ac.uk/~jm