Search found 70 matches

by shocker_0x15
Sat Feb 23, 2019 9:58 am
Forum: General Development
Topic: Shading normal issues w. adjoint bsdf
Replies: 7
Views: 860

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: 860

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: 9717

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: 3091

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: 12531

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...
by shocker_0x15
Mon Dec 04, 2017 2:31 pm
Forum: General Development
Topic: Why is volumetric emission proportional to absorption coefficient?
Replies: 7
Views: 12531

Re: Why is volumetric emission proportional to absorption coefficient?

Thanks for reply. I can find the volumetric emission term which proportional to absorption coefficient for example in, Jensen's Photon Mapping book, Spectral and Decomposition Tracking paper or Wojciech Jarosz's thesis. In the Jarosz's thesis reference, there is the following sentence by the equatio...
by shocker_0x15
Tue Nov 28, 2017 6:19 pm
Forum: General Development
Topic: Why is volumetric emission proportional to absorption coefficient?
Replies: 7
Views: 12531

Why is volumetric emission proportional to absorption coefficient?

Hi, I have a simple question as in the title. Why is volumetric emission proportional to absorption coefficient? I often see the volumetric emission term is written as volumetric_emission_term_1.png I can also see another representation, volumetric emittance function (e.g. in Mark Pauly's thesis: Ro...
by shocker_0x15
Sat Nov 25, 2017 4:02 pm
Forum: General Development
Topic: Weighted delta tracking question
Replies: 4
Views: 4845

Re: Weighted delta tracking question

The reason why I wrote 1 / (1 - P_n(x)) is that PBRT-v3's delta tracking implementation only cares about the interaction is null-collision or not, while the integral formulation in the paper simultaneously cares about three types of interaction (scattering, absorption(emission), null-collision). The...
by shocker_0x15
Sun Nov 19, 2017 11:49 am
Forum: General Development
Topic: Weighted delta tracking question
Replies: 4
Views: 4845

Re: Weighted delta tracking question

Hi, In my understanding, T_r / p_surf becomes the weight computed by cumulatively multiplying the following single step weight: single_step_weight.png as in the SD tracking paper. If this is implemented by following PBRT's interface for example for GridDensityMedium::Sample(), it returns the above w...
by shocker_0x15
Thu Jun 15, 2017 5:46 am
Forum: Visuals
Topic: My First Spectral rendering
Replies: 5
Views: 7542

Re: My First Spectral rendering

Cool ;)

What is the material?
Do you implement Hero wavelength spectral sampling?