What is PBR material in Second Life?
PBR is Second Life's physically based material system (glTF), live since 28 Nov 2023. It reacts to light more realistically than the older Blinn-Phong materials, but a viewer without PBR support only shows a fallback texture.
What PBR is
PBR stands for Physically Based Rendering. Second Life launched it on 28 November 2023 as a material system based on glTF. Instead of faking shine with a few textures, it describes what the surface is made of, and the sky, sun, and lights around you decide how it looks.
A PBR material is a set of four textures:
- Base Color + Transparency: the surface color with no lighting baked in; alpha controls overall transparency. This is what the tint changes.
- Occlusion / Roughness / Metalness: three grayscale maps packed into one texture. Metal, latex, and leather get most of their look from these.
- Emissive: color and amount of self-illumination.
- Normal: fine surface detail such as bumps and wrinkles.
PBR vs the older materials
The older materials are now called Blinn-Phong (diffuse, normal, specular). Their diffuse texture has the lighting baked in, so shine is only an approximation.
PBR works differently:
- The environment (sky and sun) contributes to reflections, so the same item can look different in different places.
- The base color has no baked lighting.
- Colors look a bit more saturated, because PBR adds tonemapping.
- A face uses either a PBR material or Blinn-Phong textures, not both at once.
What you need
- A viewer with PBR support. On a viewer without it, you only see the item's fallback Blinn-Phong texture (by default the plain wood texture, unless the creator added a baked fallback).
- A machine that can handle it. If it lags, the official wiki suggests lowering these graphics settings: Transparent Water off, Screen Space Ambient Occlusion off, Shadows none, Screen Space Reflections off, Reflection Detail "Static Only", Reflection Coverage "Manual only". Local lights are now controlled by the "Quality & Speed" slider under World > Improve graphics speed.
Common problems
- The item looks different in different places: normal for PBR. Color and shine follow the light around you.
- A black tint turns white: see Why does a pure black PBR tint turn white?.
- Lag in a busy area: many reflection probes in one place can cause artifacts and lag. That is a property of the area, not of your item.
Source: Second Life Wiki: PBR Materials