[Radiance-general] ambient occlusion map ?

[Brajesh Lal]

Hi Christopher

Actually i am computing per pixel visibility ( or say each point visibility of the surface) in the up direction. I suppose if we set ambiance bounce more than zero, then it will have inter-reflection effect. and to avoid interreflection contribution i have done surface material perfectly black and bounces zero.

Yes we do need light source, for that i am using glow ( self luminous surface  ) and a unity hemispherical light source for a point.

and logically i suppose -completely visible point is shaded as unity, and zero will be treated as occluded. so value of rgb determines the visibility factor.

-i option produces  irradiance map. 


so basically i render the scene 
rpict  -x resx, -y resy -i -ab 0 -vf camera.vp  scene.oct > scene.hdr


Best Regards,     Brajesh Lal


________________________________
 From: Christopher Rush <Christopher.Rush at arup.com>
To: Radiance general discussion <radiance-general at radiance-online.org> 
Sent: Friday, March 15, 2013 3:57 PM
Subject: Re: [Radiance-general] ambient occlusion map ?
 

You will need at least one ambient bounce to calculate the contribution of an ambient “glow” source. Zero ambient bounces means only direct sources like “light” would be traced.
 
Also, I’m not sure, but the rpict manual says the -i option actually estimates the irradiance using the radiance value and the lambertian reflectance. I’ve never delved into the code, so I’m not sure how accurate that description is. After testing -ab 1, you might also try assigning a very small reflectance to your black surface.
 
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