Questions tagged [ibl]

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1 answer

Integrating BRDF using Importance Sampling

I read some articles about BRDF integration with and without importance sampling and I don't understand one thing in equations. If we integrate a BRDF over hemisphere with uniform sample direction ...
1 vote
0 answers

Contour-line looking artifact on diffuse irradiance map

I tried implementing my own diffuse irradiance map maker after reading Learn OpenGL > PBR > IBL > Diffuse Irradiance. It takes an HDR image and makes six HDR cube map. But It keeps making ...
2 votes
3 answers

PBR : Understanding the right part of Split sum integration of specular IBL

This is the website I am learning from. In the specular part of IBL this is the split sum approximation Now the left part of the equation I have asked in This post and I have understood everything ...
  • 169
3 votes
0 answers

Comparing different sampling methods for GGX IBL

I have made a demo that shades a sphere with an environment map. I wanted to compare 3 different ways of sampling the environment. Uniform sampling. Importance sampling with the NDF as suggested in ...
0 votes
1 answer

Problem sampling uniformly envmap with GGX

I have made a program that samples uniformly an environment map and computes the lighting using the GGX BRDF. I have made a small example that reproduces the issue I'm having. You can check it out ...
0 votes
1 answer

How Image Based Lighting is applied to indoor scene?

Now the mainstream engine's approach is to use image-based lighting to achieve approximate global illumination, but such a technique seems to be only applicable to outdoor scenes.What kind of ...
0 votes
1 answer

Weirdly looking diffuse irradiance map

I have problem with creating diffuse irradiance map. As reference I am using and
16 votes
3 answers

Importance Sampling of Environment Maps

What is the best currently known and ideally also production-verified approach for sampling environment maps (EM) in a MIS-based uni-directional path tracer and similar types of renderers? I would ...
  • 1,405
6 votes
1 answer

Image based lighting, tangent space coordinates, and optimization

When I saw an implementation of normal mapping that computed the TBN matrix in the vertex shader and converted everything (in particular the view vector and light vector) to tangent space at that ...