Timeline for Refraction: given an incoming and transmitted direction, can I deduce the normal?
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
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| Jun 27, 2018 at 22:07 | comment | added | Marc HPunkt | haha. of course R+I. Man I wrote some very useless complicated stuff. I can recommend this blog post which is a very good treatment of fersnel. seblagarde.wordpress.com/2013/04/29/memo-on-fresnel-equations | |
| Jun 27, 2018 at 22:03 | comment | added | Phil McLaughlin | For reflection, normalize(R + I) = N unless dot(R, I) == 0, in which case there's no collision anyway. Refraction is the tricky part. | |
| Jun 27, 2018 at 21:57 | comment | added | Phil McLaughlin | So, yes I know the "true normal" at any point on the surface, but microfacet BRDFs work by treating every point as having many very small facets whose normals are different from the true normal, and you pick one from a probability distribution. Connecting edges in bidirectional path tracing requires being able to determine the probability of generating point x + 1 given point x, which would depend on what normal you get from the distribution. I want to be able to say "ok I need this particular normal to make this bounce happen" so I can ask the distribution how likely that is. | |
| Jun 27, 2018 at 21:53 | history | answered | Marc HPunkt | CC BY-SA 4.0 |