KHRMaterialsEmissiveStrength

KHR_materials_emissive_strength defines emissive strength and enables high-dynamic-range (HDR) emissive materials.

The core glTF 2.0 material model includes emissiveFactor and emissiveTexture to control the color and intensity of the light being emitted by the material, clamped to the range [0.0, 1.0]. However, in PBR environments with HDR reflections and lighting, stronger emission effects may be desirable.

In this extension, a new emissiveStrength scalar factor is supplied, which governs the upper limit of emissive strength per material and may be given arbitrarily high values.

For implementations where a physical light unit is needed, the units for the multiplicative product of the emissive texture and factor are candela per square meter (cd / m2), sometimes called nits. Many realtime rendering engines simplify this calculation by assuming that an emissive factor of 1.0 results in a fully exposed pixel.

Properties:

• EmissiveStrength

Example

import { KHRMaterialsEmissiveStrength, EmissiveStrength } from '@gltf-transform/extensions';

// Create an Extension attached to the Document.
const emissiveStrengthExtension = document.createExtension(KHRMaterialsEmissiveStrength);

// Create EmissiveStrength property.
const emissiveStrength = emissiveStrengthExtension
    .createEmissiveStrength().setEmissiveStrength(5.0);

// Assign to a Material.
material.setExtension('KHR_materials_emissive_strength', emissiveStrength);