Search found 75 matches

by shocker_0x15
Sat Jul 13, 2019 3:02 pm
Forum: General Development
Topic: Light-tracer weights
Replies: 9
Views: 1495

Re: Light-tracer weights

If I understand you correctly, by omitting this PDF in the pathtracer I need an additional weigh in the lightracer, right? Correct. Quoting PBRT again, are you talking about the following PDF? Yes. We need to pay attention when talking about light-tracing (and Bidirectional Path Tracing), so I need...
by shocker_0x15
Thu Jul 11, 2019 1:41 pm
Forum: General Development
Topic: Light-tracer weights
Replies: 9
Views: 1495

Re: Light-tracer weights

I don’t mean the naive pathtracer implementation by “division by PDF to generate the first intersection point”. Do your path tracing implementation (both with and without NEE) take the “PDF to generate the first intersection point” into account? That PDF is a PDF to generate a primary ray from a cam...
by shocker_0x15
Thu Jul 11, 2019 8:51 am
Forum: General Development
Topic: Light-tracer weights
Replies: 9
Views: 1495

Re: Light-tracer weights

Why do you think it shouldn't be there?
I think it depends on the ground truth implementation.
What is your expected brightness? Is it the result of path tracing?
If so, does it contain the division by PDF to generate the first intersection point (the second vertex if the first is on lens)?
by shocker_0x15
Wed Jul 10, 2019 5:44 pm
Forum: General Development
Topic: Light-tracer weights
Replies: 9
Views: 1495

Re: Light-tracer weights

However sometimes I see an implementation of path tracing which omits the division by the PDF of the first intersection (i.e. PDF for the next vertex to a point on lens). If you want to match the result to the implementation like this, you need to take additional factors to light-tracing into the ac...
by shocker_0x15
Wed Jul 10, 2019 5:23 pm
Forum: General Development
Topic: Light-tracer weights
Replies: 9
Views: 1495

Re: Light-tracer weights

I strongly suspect it is related to sample weights, when I connect to the camera. For now I only consider a pin hole camera with a lens radius of zero. Does “connect to the camera” mean that you are trying to do NEE with light tracing? If so, I have feeling that your weight calculation contains man...
by shocker_0x15
Sat Feb 23, 2019 9:58 am
Forum: General Development
Topic: Shading normal issues w. adjoint bsdf
Replies: 7
Views: 1991

Re: Shading normal issues w. adjoint bsdf

It might be help for you to visualizing the relation between geometric normal and shading normal like this: clamp( RGB( 0.5 + 10 * (dot(shadingNormal, geometricNormal) - 1), 0.5 + 100 * (length(geometricNormal) - 1), 0.5 + 100 * (length(shadingNormal) - 1) ) , 0, 1) This shows completely a gray imag...
by shocker_0x15
Fri Feb 22, 2019 3:14 am
Forum: General Development
Topic: Shading normal issues w. adjoint bsdf
Replies: 7
Views: 1991

Re: Shading normal issues w. adjoint bsdf

I don’t have a clear answer for your question, but I think there is a limitation with shading normal because it doesn’t have physical basis (as Veach noted). One apparent way to mitigate arbitrarily large values is using well polygonized model which has shading normal similar to geometric normal... ...
by shocker_0x15
Thu Sep 20, 2018 1:41 pm
Forum: Links & Papers
Topic: CUDA 10 available
Replies: 6
Views: 10546

Re: CUDA 10 available

We can already find a description about new features in the next OptiX from Google search (e.g. GeometryTriangles).
According to that, the next version of OptiX becomes 5.2 :)
by shocker_0x15
Mon Mar 05, 2018 5:23 pm
Forum: General Development
Topic: Geometry factor for parallel light?
Replies: 2
Views: 3886

Re: Geometry factor for parallel light?

I'm not sure if I understand your question, but I think 1 / r^2 term should always be considered and is implicitly considered if you trace a path from the light source even if it is parallel light. Light path construction is performed as follows: sample a point y0 on the light with pdf p_A(y0) and g...
by shocker_0x15
Fri Dec 08, 2017 6:34 pm
Forum: General Development
Topic: Why is volumetric emission proportional to absorption coefficient?
Replies: 7
Views: 13484

Re: Why is volumetric emission proportional to absorption coefficient?

My current thinking process when reading the paper you lastly mentioned is like following: 0. However, the mental model behind radiance transfer is not one that considers the interaction of individual particles. - Yes, I know. 1. eq. (1) says that contribution from source radiance Lm(x', w) is propo...