# Questions tagged [ibl]

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1 vote
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### 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 ...
• 183
1 vote
48 views

### 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 ...
• 111
323 views

### 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
254 views

### 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 ...
• 117
50 views

### 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 ...
• 117
378 views

### 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 ...
177 views

### Weirdly looking diffuse irradiance map

I have problem with creating diffuse irradiance map. As reference I am using https://learnopengl.com/PBR/IBL/Diffuse-irradiance and https://github.com/TheEvilBanana/PhysicallyBasedRendering/blob/...
3k views

### 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 ...
• 1,377