PBR Guide HELP

ikatalytic

Hey all, I'm reading Allegorithmic's PBR guide as part of my university studies and wondered if anybody would be able to tell me what a texture sampler is and what texture interpolation is? I've had a brief look at the polycount wiki and I'm still struggling to get my head round them. Thanks in advance.

HaukeThiessen

Sampling refers to the process of looking up the color information on a texture according to the uv coordinates of a given point on the mesh surface. When you render a mesh, the renderer looks up what mesh and what point on the surface of the mesh is visible in the pixel and finds the corresponding point on the texture, according to the uv coordinates and tiling settings. Since this process leads to visual artifacts due to resolution differences and distortions, texture interpolation is needed.

https://en.wikipedia.org/wiki/Texture_filtering

This article describes texture interpolation (the terms filtering and interpolation are nearly interchangeable).

While it's not necessary to know all texture interpolation methods, it's good to know that sampling a texture will always result in a slight quality loss. And especially with textures showing very small structures or grids, it's good practice to preview the textues applied to meshes in the engine to see if there are visual artifacts.