Search found 5 matches

by vchizhov
Fri Apr 26, 2019 10:18 pm
Forum: General Development
Topic: Point lights and non-diffuse brdfs
Replies: 9
Views: 1569

Re: Point lights and non-diffuse brdfs

Thanks anyways, I appreciate it. I'll keep looking for a formal proof, and if I find one I'll make sure to link it for future readers.
by vchizhov
Fri Apr 26, 2019 7:27 pm
Forum: General Development
Topic: Point lights and non-diffuse brdfs
Replies: 9
Views: 1569

Re: Point lights and non-diffuse brdfs

Thank you, I have looked through pbrt already, but just saying - "it's a Dirac delta" is hardly mathematically robust - there's no derivation. It doesn't even derive central relationships like \frac{\cos\theta}{r^2}dA = d\omega . It doesn't try to evaluate the incoming radiance directly, but instead...
by vchizhov
Fri Apr 26, 2019 3:27 pm
Forum: General Development
Topic: Point lights and non-diffuse brdfs
Replies: 9
Views: 1569

Re: Point lights and non-diffuse brdfs

I understand it in the sense that you want just that one direction, however, I don't see how that solves the intensity vs radiance issue. After all the rendering equation considers radiance and not intensity. If you really need academic respectability to be convinced, maybe you should take a look at...
by vchizhov
Thu Apr 25, 2019 7:11 pm
Forum: General Development
Topic: Point lights and non-diffuse brdfs
Replies: 9
Views: 1569

Re: Point lights and non-diffuse brdfs

I am aware that a point light is not physical, I am just wondering how the commonly accepted formulae in real-time cg are motivated. They are using in most cases the intensity as if it were radiance, with brdfs defined in terms of radiance. Do you have a reference for the part where you mention that...
by vchizhov
Wed Apr 24, 2019 5:00 pm
Forum: General Development
Topic: Point lights and non-diffuse brdfs
Replies: 9
Views: 1569

Point lights and non-diffuse brdfs

I've had a question that I couldn't answer myself and haven't found any formal derivation on the topic. If one has a point light with position \vec{c} and intensity I , then the irradiance at point \vec{p} at some surface can be derived as: E(\vec{p}) = \frac{d\Phi}{dA} = \frac{d\Phi}{d\omega}\frac{...