Glossary

PBR Materials

PBR (Physically Based Rendering) is the modern standard for representing surface materials in real-time 3D, including web 3D and AR. Instead of fixed shaders that approximate how a material looks, PBR materials describe physical properties (base color, roughness, metallic value, surface normal), so renderers can compute realistic lighting consistently across devices. PBR is native to glTF/GLB and is what makes a model look the same in Blender, in the browser via Three.js, in Apple Quick Look and on Apple Vision Pro.

Quick Facts

Stands for
Physically Based Rendering
Core idea
describe materials by physical properties, not visual approximation
Standard channels
base color, metallic, roughness, normal, ambient occlusion, emissive
Format support
native in glTF 2.0 and GLB
Renderer support
Three.js, model-viewer, Quick Look, Scene Viewer, RealityKit, all modern engines
Why it matters
a model looks the same across devices and renderers

Before PBR, every 3D engine and tool used its own ad-hoc shader model. A material that looked correct in one engine looked wrong in another, and matching real-world surfaces required artist tweaks per renderer. PBR fixed that, by describing materials by their physical properties rather than by appearance.

The standard glTF PBR material consists of: base color (the albedo, the surface’s true colour without lighting), metallic (how metal-like the surface is, 0 to 1), roughness (how smooth or rough, 0 to 1), and a normal map for surface detail without extra geometry. Optional channels add ambient occlusion, emissive light, clearcoat and others. Each channel can be a flat value or a texture map.

Because every PBR-compatible renderer interprets these inputs the same way, a model authored in Blender with PBR materials looks consistent on the web via Three.js or model-viewer, in Apple Quick Look on iOS, in Google Scene Viewer on Android, and on Apple Vision Pro or Samsung Galaxy XR. That cross-platform consistency is what makes PBR essential for 3D and AR on a website. A model uploaded to PausAR Viewer carries its PBR materials all the way to the user’s device.

PBR materials are how a 3D model can look like an actual wooden table or a brushed-metal handle, without per-platform tuning. They are also why GLB has won as the web format: the GLB exporter includes a fully defined PBR material on every mesh by default.

Comparison

ChannelWhat it controlsTypical input
Base colorThe surface's actual colour (albedo)Texture or flat colour
MetallicHow metal-like the surface is0 to 1 value or texture
RoughnessHow smooth or rough the surface is0 to 1 value or texture
Normal mapSurface detail without extra geometryNormal map texture
Ambient occlusionSelf-shadowing in crevicesGrayscale texture
EmissiveSelf-lit surfaces (screens, lights)Colour or texture

FAQ

Do I need PBR materials for Web AR?

In practice, yes. The GLB and USDZ formats both expect PBR materials, and modern AR viewers (Quick Look, Scene Viewer, model-viewer) render PBR by default. Non-PBR materials work but tend to look wrong under real lighting in AR.

What's the difference between PBR and traditional 3D materials?

Traditional materials describe appearance directly (shiny, matte, with this much specular). PBR describes physics (this is metal, this roughness), and the renderer computes the appearance from real lighting. The result is consistent across renderers and lighting conditions.

Where do I create PBR materials?

Blender handles PBR natively with its Principled BSDF shader. Other common tools include Substance Painter for textures, and most CAD-to-mesh pipelines now output PBR by default.

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