THREE.JS / FOUNDATIONS 242

Let light travel through the asset.

Transmission, volume, IOR, specular response, dispersion, iridescence, and sheen form an optical stack. This study keeps the stack inside a real glTF asset so the loader mappings, texture channels, and compatibility rules stay visible.

Preparing glTF fixture—

Building closed optical geometry, transmission maps, and a loader-parsed asset…

backend: —
extensions: —
optical mats: —
focus: —
frame ms: —

Optical stack controlswaiting

material focus transmission factor 0.96 surface IOR 1.52 volume thickness 0.82 attenuation distance 2.40 specular intensity 0.75 dispersion 0.35 iridescence 0.84 iridescence IOR 1.33 film thickness 450 sheen 0.72 sheen roughness 0.28 environment exposure 1.16

use optical maps rotate stage auto-rotate camera

The parsed glTF materials will appear after the loader finishes.

Optical extension contractwaiting

transmissionR · linear

waiting

volume thicknessG · linear

waiting

IOR[1, 2.333]

waiting

specularA + RGB

waiting

dispersionscalar · transmissive

waiting

iridescenceR + G thickness

waiting

sheenRGB + A

waiting

environmentPMREM context

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Transmission controls light crossing the surface; volume adds thickness and absorption; IOR bends the path; specular controls non-metal reflectance; dispersion separates transmitted colors; iridescence shifts a thin film; sheen adds a soft grazing highlight.

The study uses the real GLTFLoader extension path and tracks every loaded resource for explicit release.

Derived from the official glTF transmission example, glTF dispersion example, transmission example, GLTFLoader, MeshPhysicalMaterial, and the Khronos glTF material extensions. Use ?forceWebGL=1 to inspect the labeled WebGL2 reference.

LAB 242 / GLTF OPTICAL MATERIALS