THREE.JS / FOUNDATIONS 245

The UVs are part of the asset.

KHR_texture_transform lets a glTF textureInfo carry atlas offsets, scale, rotation, and a UV-set override. The real loader turns those declarations into cloned Three.js textures, so one image can serve several material layouts.

Preparing glTF fixture—

Building four atlas panels and a loader-parsed texture-transform asset…

backend: —
maps: —
channels: —
focus: —
frame ms: —

Texture transform controlswaiting

material focus stage orbit 0.70 environment exposure 1.10

apply asset transforms wireframe show UV frames auto-rotate camera

The loader will map the textureInfo extension before the first frame.

KHR_texture_transform contractwaiting

atlas cropoffset + scale

quarter-turnrotation around origin

UV1 overridetexCoord = 1

raw referenceno extension

atlas cropoffset / scale

waiting

quarter-turnrotation

waiting

UV channeltexCoord override

waiting

texture identityclone + shared source

waiting

samplerwrap + color space

waiting

loader resultmap channels

waiting

The extension changes texture sampling coordinates; it does not modify vertex UV buffers or create a second image.

The study uses GLTFLoader's native KHR_texture_transform path and tracks the base image plus every cloned texture for explicit release.

Derived from the official glTF loader example, GLTFLoader, Texture, and the Khronos KHR_texture_transform contract. Use ?forceWebGL=1 to inspect the labeled WebGL2 reference.

LAB 245 / GLTF TEXTURE TRANSFORMS