Image by <a href=mailto:"nickamy@paradise.net.nz">Nicholas Chapman aka OnoSendai</a><br/>Posted 2005-10-29<br/><br/><img src="galleria/fullsize/onosendaiim1130416397.png"/><h1>Description</h1><br/>An image from my spectral Monte-Carlo path tracer.
Instead of each ray having a RGB triplet of radiances, each ray has a radiance for a single wavelength, where the wavelength is randomly selected from a range that is usually about that of the visible wavelengths, eg 400-700nm. The light source in this image emits uniformly over the visible wavelengths.
So when a ray is spawned, a particular wavelength is chosen, and the ray bounces around the scene. The final RGB contribution of the ray is calculated by mapping the (wavelength, radiance) pair to XYZ colour using the CIE XYZ curves, then linearly transforming the XYZ colour to RGB colour.
Dispersive refraction (different indices of refraction at different wavelengths) is implemented, and is responsible for the rainbow-ish colours near the base of the glass.
The image took 11000 seconds to render, and used 2500 primary samples per pixel.
More info and images at <a href="http://homepages.paradise.net.nz/nickamy/">http://homepages.paradise.net.nz/nickamy/</a>
the wavy edges around the very bottom edge of the glass are due to mesh artifacts i think, yeah. Dunno about the higher frequency ones just above the rainbow. I am using smoothed normals, but apparently that\'s not enough :)
Really nice Ono, I know you\'ve been working hard on this.
Just one thing, you cannot see the far side of the glass. I am can see the near side, and the edges, and then it seems to dissapear. Is this a problem? Do you know see what I\'m referring too?
