Questions tagged [pbr]

Physically-based rendering (PBR), sometimes referred to as physically-based materials or physically-based shading, is a 3D graphics rendering process that attempts to produce realistic images by accurately modeling light-matter interaction. Use this tag for questions about physically-based rendering, including shading, lighting, and materials.

Physically-based rendering (PBR), sometimes referred to as physically-based materials or physically-based shading, is a 3D graphics rendering process that attempts to produce realistic images by accurately modeling light-matter interaction. Different rendering engines may employ different methods and use different input parameters to target this goal.

Information

Examples

Parameters

Most PBR systems include some means to set how rough a surface is, and how metallic a surface is. One parameter may have multiple effects, for example increasing the roughness may blur the reflection map and spread out the specular highlight at the same time. This example image is a composite of outputs from the OSGJS PBR demo linked above:

Samples of PBR roughness and metallic-ness

66 questions
0
votes
1 answer

Physically Based Shading, IBL, Half Vector, and NDotR vs NDotV

I'm trying to figure out some simple concepts about image based lighting for PBR. In many documents and code, I've seen the light direction (FragToLightDir) being set to the reflection vector (reflect(EyeToFragDir,Normal)). Then they set the half…
Robert
  • 413
  • 4
  • 12
0
votes
0 answers

Does any know how UE calculate the rayleigh scattering coefficient?

In the file "SkyAtmosphereComponent.cpp", I've found the rayleigh scattering coefficient: const FLinearColor RayleightScatteringRaw = FLinearColor(0.005802f, 0.013558f, 0.033100f); But UE don't tell what the formula it bases on, only the…
0
votes
2 answers

Physically Based Rendering shows discontinuity on closed surface

I added a mesh to a pyvista.Plotter() with p.add_mesh(mesh, show_edges=True, color='linen', pbr=True, metallic=0.8, roughness=0.1, diffuse=1) but it displays with a discontinuity (where the mesh started and ended) Why is this junction of cells…
user258279
  • 371
  • 4
  • 12
0
votes
1 answer

Assimp FBX loader and PBR textures

I would like to know if the assimp FBX loader does supports PBR materials. I am currently using it with glTF/glb files and it perfectly loads my PBR textures. I am loading PBR textures via the "assimp/pbrmaterial.h" header file, but this file is…
Bicyclette
  • 13
  • 2
0
votes
1 answer

Generating a proper alpha (transparency) value out of a PBR material

I'm writing a PBR shader and I'm trying to determine the correct way to generate the alpha value that is output for the image. The goal is to have a final image that is 'premultiplied alpha', so it can be used with another Over composite operation…
mb13
  • 139
  • 12
0
votes
0 answers

Mixing Phong and PBR materials in three.js

I have an application that includes meshes rendered with MeshPhongMaterials. They work well with the full suite of lights available in three.js. However, I want to combine them with imported GLB/GLTF models. In order to have the models lit, I…
Morne
  • 11
  • 3
0
votes
2 answers

SCNParticleSystem partially hidden or occluded in wrong manner

I have an issue with particle systems, which can be, in rare cases, kind of occluded in a wrong manner. The particle system you see on the print-screens is a sphere (with invisible material, material transparency = 0.0), that emits particles from…
ZAY
  • 3,882
  • 2
  • 13
  • 21
0
votes
0 answers

pbrt question about unresolved external symbol

Recently, I am stduying pbrt(physically based rendering). However, I have a question in using it in VS2019. I have cmaked the pbrt system(using the command "git clone --recursive https://github.com/mmp/pbrt-v3/"), and included it in VS. After I have…
0
votes
0 answers

PBR - Incorrect direct lighting

Based on many internet resources I wrote PBR implementation for directional lighting for my DirectX 11 game engine, but It works incorrectly. Bellow, you can see a screenshot where I forced metalness to 0.0f and roughness to 1.0f. As you can see…
bilek993
  • 85
  • 11
0
votes
1 answer

Direct3D11 / PBR Shader - Scene keeps too dark - any experience with the a BRDF (Burley/Disney) Shader?

I dived successfully into DirectX/3D11 (SharpDX/C#), I brought everything to life and finally, I wanted to implement PBR. I highly wanted the one-and-only BRDF like Disney / Burley, and luckily I've found the Microsoft Shipped PBREffect.fx in the…
0
votes
1 answer

Error while cmake the filament rendering project

I was trying to Cmake the google filament project (https://github.com/google/filament ). But I came across the error show below. I have followed the steps mention in the Windows build section, but still have the error. Is there any other way to…
Kasun
  • 187
  • 3
  • 15
0
votes
1 answer

Wrong result when solving the bright dots in pre-filter convolution

In learnopengl specular IBL tutorial, to solve the bright dots in the pre-filter convolution, tutorial references this article and the pre-filter calculation are following: float3 PreFilterEnvMap(TextureCube envMap, sampler samEnv , float roughness,…
Outro
  • 89
  • 6
0
votes
1 answer

ThreeJS GLTFExporter doesn't export PBR material maps

I have a simple Cube with a PBR Material. Used maps are color, metalness, roughness, bump. When I export the scene via this code, the exported glb is missing all maps but the color. Is this a bug in ThreeJS? e = new…
nurbs999
  • 87
  • 10
0
votes
0 answers

Unity 3d PBR shader graph: replace transparency with color

I am using unity 2018.3.5f1 with Shader Graph 4.9.0 and Lightweight RP 4.9.0. I want to create shader that will be replacing transparent part of the texture with color. This is how my shader graph looks like the issue is that I receive weird…
Seoner
  • 101
  • 8
0
votes
0 answers

How to fix floating point errors in OpenGL PBR

After finishing my PBR implementation I noticed that when I get close to a reflective surface, artifacts appear which I think are floating point errors. I would really wish not to using doubles as my GPU tends to handle doubles in a performance…
James Nguyen
  • 1,079
  • 1
  • 10
  • 20