#physically based rendering

According to my notes:

The colors texture has RGB for albedo and A for some fresnel bullshit.

The "mix" texture is packed PBR with R=occlusion, G=likely roughness, B=specularity.

There's something funky going on with villager body textures compared to their face, where there's only an occlusion map.

Normal maps are as expected.

Opacity, where needed, is in an "op" texture.

Looking at the downloaded models from The Models Resource, the packed stuff is all unpacked and labeled:

The fresnel bullshit from the albedo A channel is "crv", which sent me down a rabbit hole and a half before.

Mix G is missing entirely, leaving only R="ocl" and b="spc".

For body textures, there's no specular map either.

Now, looking into it a little deeper in RenderDoc, I see why:

vec2 _640 = texture(fp_t_tcb_C, vec2(_86, _88)).xz; float _642 = _640.x; float _644 = _640.y;

Or more readable:

vec2 oclSpc = texture(mixSampler, uv.xy).xz; float occlusion = oclSpc.x; float specular = oclSpc.y;

And for the body specifically, it's like this:

float occlusion = texture(mixSampler, uv.xy).x;

So that's why there's several different shaders in use here, huh? But wait, it gets better!

According to my notes, this applies to outfits too. Nothing could be wronger.

vec4 mixStuff = texture(mixSampler, uv.xy)).xyzw;

This is grabbing all the stuff and one more to boot! In the RenderDoc capture I'm using here, Audie is wearing a tracksuit, which has these textures:

That's albedo RGB, albedo A (fresnel stuff), mix R (metalicity?) G (occlusion) B (some "edge" bs?), and A (roughness?). Not shown: the opacity map.

I got that from comparing things to the tropical muumuu that Audie normally wears, whose textures are included in the TMR download.

If you work in 3D art, game development, or rendering, you’ve probably heard the term PBR texture generator. But what does it actually mean, and why is it such an important tool in modern workflows?

Let’s break it down in a practical way.

First: What Does PBR Mean?

PBR stands for Physically Based Rendering.

It’s a shading and lighting model designed to simulate how light behaves in the real world. Instead of manually tweaking materials until they “look right,” PBR uses physically accurate surface values so materials respond consistently under different lighting environments.

This is why PBR materials look correct whether you're rendering in Unreal Engine, Unity, Blender, or another modern engine.

What Is a PBR Texture Generator?

A PBR texture generator is a tool that creates a full set of physically based texture maps for a material.

Instead of painting each map manually, the generator produces coordinated texture maps such as:

Albedo (Base Color)

Normal

Roughness

Metallic

Ambient Occlusion

Height or Displacement (optional)

These maps work together inside a PBR shader to create realistic surfaces.

Why Artists Use PBR Texture Generators

Creating materials from scratch can be time-consuming, especially when building large environments or asset libraries.

A PBR texture generator helps by:

Speeding up material creation

Maintaining consistency across assets

Generating seamless tiling textures

Allowing fast iteration

Reducing manual technical setup

For game artists and environment designers, this can significantly improve workflow efficiency.

How PBR Texture Maps Work Together

Here’s a quick breakdown of the most important maps:

Albedo Map

Contains pure color information with no lighting or shadows baked in.

Normal Map

Adds surface detail without increasing polygon count.

Roughness Map

Controls how shiny or matte a surface appears.

Metallic Map

Defines whether a surface behaves like metal or a non-metal material.

Ambient Occlusion

Adds subtle shadowing in crevices to enhance depth.

When these maps are correctly generated and aligned, materials react realistically under dynamic lighting.

Where PBR Texture Generators Are Used

You’ll commonly see them in:

Game development

Architectural visualization

Product rendering

VR and AR experiences

Film and VFX production

Because PBR is now an industry standard, generators that support this workflow are widely adopted.

Procedural vs Image-Based Generation

There are generally two main approaches:

Procedural Generation

Materials are created using adjustable parameters like noise, grain, wear, or surface damage. This allows high flexibility and seamless tiling.

Image-Based Conversion

A single image can be converted into multiple PBR maps using automated analysis.

Each approach has strengths depending on the project needs.

Things to Watch Out For

Even with a PBR texture generator, there are common mistakes:

Using incorrect metallic values (metals are usually either 0 or 1)

Overusing ambient occlusion

Ignoring real-world scale

Mixing metallic-roughness and specular workflows improperly

Understanding PBR fundamentals helps avoid these issues.

Why PBR Texture Generators Matter Today

Modern engines rely on physically accurate materials. As rendering becomes more realistic (especially with real-time ray tracing), properly structured PBR materials are essential.

A PBR texture generator is not just a convenience tool - it supports a standardized workflow that improves visual consistency and production efficiency.

会社員になってからすっかり画像認識の人になってしまったけど、最近のCGレンダリング事情にキャッチアップしておきたい。 リアルタイムレンダリング系の書籍を買っておきながらしばらく積んでいた↓ 画像認識もCGも、リアルタイム化を目指す際の考え方は共通点が多いと最近感じる。 極力ユースケースを絞って重い処理はなるべく事前計算へ追いやり、キャッシュをフル活用してリッチな処理を近似する。実行時の自由度と処理負荷のバランスを調整していく。。 応答のリアルタイム性を追求するとどんなジャンルでも考え方は似通ってくるのかな。 レンダラやGPUアーキテクチャの話もあるけど、基本はやっぱりBRDF(反射)なので、とりあえずミクロなスケールでShaderの話からキャッチアップして行こう。 今月のCG WORLDはPBR (Physically Based Rendering)特集だったね。 (more…)

(Image shows a GPU pathtraced tinted glass bunny with some non-reflective patches and some other objects with different materials being illuminated by a box light source)

About two weeks ago I scrapped together some old GPU pathtracing code for a small demo for some school students. It was able to do basic diffuse lighting and perfect reflection and reflection of spheres and boxes.

I like pathtracing, so I spent a few evenings putting some more stuff into it, like bounding volume hierarchies, some more BSDFs, direct light sampling, different importance sampling techniques and texture support for diffuse and specular components. Everything is a bit hacky and not super optimized in shader code, but it runs interactively (though depending on the scene, this is like 1 FPS). Nethertheless, it works and looks decent enough and I had a bit of fun coding.

(Sponza model with area light source, a mirror and a glossy sphere)

(Sponza model with area light source, a mirror and a glossy sphere, this time with higher roughness, making the reflection look more diffuse)

(different translucent objects. The refracted light is focused nicely on the other side of the objects)

Review: Substance Painter 2

I found Substance Painter incredibly easy to use and the workflow just seemed to make sense. The interface is ordered and customisable which is perfect as you start to get used to the tools.