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Questions tagged [pdf]

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1 vote
1 answer
195 views

Confusion about PDF defined in solid angle / area measure

When using MIS, we always want to express the PDF value in a unified measure in order not to render the ratio between them meaningless. Yet when I read through chapter 16 of PBR-book, I got confused ...
Enigmatisms's user avatar
2 votes
1 answer
127 views

Integral over cosine weighted sphere cap/cone

I'm not sure I have the right terminology, but in rendering it can be useful to draw cosine weighted samples from a hemisphere. In this case the integral (over the weights) is Pi. Now I don´t want to ...
B_old's user avatar
  • 203
1 vote
1 answer
362 views

PDF for sampling emissive meshes for NEE/MIS

I'm writing a Monte Carlo path tracer, and I'm trying to allow any mesh to be an emitter, but I'm not entirely sure about the probabilities to use when I sample them. Right now, my algorithm for light ...
uhwo's user avatar
  • 55
1 vote
1 answer
42 views

How can I step through a pdf file while maintaining a fixed viewport for each page?

I have developed some software that generates a pdf file for visualizing air traffic. Each page shows a plan view of the traffic at a point in time, with a small time step (e.g., 20 seconds) from one ...
Russ P.'s user avatar
  • 11
0 votes
1 answer
330 views

How can I make the simplest physically based mixed specular-diffuse BRDF (and how to properly sample it)?

I am having troubles making a BRDF that has both specular and diffuse part. Each one is weighted by a coefficient and the sum of coefficients should be equal to one. I want this layered BRDF to be the ...
Balfar's user avatar
  • 76
1 vote
1 answer
191 views

How to find the importance sampling function for a specified BRDF?

I am currently working on BRDF and their associated probability density functions (PDF) in order to importance-sample them. It is really hard for me to find the correct way to compute the PDF of a ...
Balfar's user avatar
  • 76
0 votes
0 answers
28 views

Do scanners and scanning software compensate and enhance blurry sources?

I received a pdf from a client containing several invoices. Upon further inspecting, some lines on the invoice seem digitally produced. When I tried selecting the page, copying it then pasting it on ...
obi's user avatar
  • 1
1 vote
0 answers
77 views

Why isn't the 'Map Colors' fixup changing text colors?

I saw this question some where, I think Reddit, but I can't find it. I have same issue. Please see the screenshot beneath. I've uploaded the PDF to mega.nz I'm using Adobe Acrobat Pro DC Version 2019....
user avatar
0 votes
0 answers
62 views

An equation about PDFs and differentials in the book of pbrt-v3

Why does the equation at the bottom of the following page hold? http://www.pbr-book.org/3ed-2018/Monte_Carlo_Integration/Transforming_between_Distributions.html $p(\theta,\phi)d\theta d\phi=p(\omega)...
chaosink's user avatar
  • 591