@babylonjs/loaders
Version:
For usage documentation please visit https://doc.babylonjs.com/features/featuresDeepDive/importers/loadingFileTypes/.
116 lines • 6.71 kB
JavaScript
import { Color3 } from "@babylonjs/core/Maths/math.color.js";
import { Vector3 } from "@babylonjs/core/Maths/math.vector.js";
import { GLTFLoader } from "../glTFLoader.js";
import { registerGLTFExtension, unregisterGLTFExtension } from "../glTFLoaderExtensionRegistry.js";
const NAME = "KHR_materials_volume_scatter";
function multiScatterToSingleScatterAlbedo(multiScatter) {
const multiScatterAlbedo = new Vector3(multiScatter.r, multiScatter.g, multiScatter.b);
const s = new Vector3(4.09712, 4.09712, 4.09712);
s.addInPlace(new Vector3(4.20863, 4.20863, 4.20863).multiplyInPlace(multiScatterAlbedo));
const p = new Vector3(9.59217, 9.59217, 9.59217);
p.addInPlace(new Vector3(41.6808, 41.6808, 41.6808).multiplyInPlace(multiScatterAlbedo));
p.addInPlace(new Vector3(17.7126, 17.7126, 17.7126).multiplyInPlace(multiScatterAlbedo.multiply(multiScatterAlbedo)));
s.subtractInPlace(new Vector3(Math.sqrt(p.x), Math.sqrt(p.y), Math.sqrt(p.z)));
return new Vector3(1.0, 1.0, 1.0).subtract(s.multiply(s));
}
/**
* TODO: In-progress specification
* [Specification](https://github.com/KhronosGroup/glTF/blob/7ea427ed55d44427e83c0a6d1c87068b1a4151c5/extensions/2.0/Khronos/KHR_materials_volume_scatter/README.md)
* @experimental
* @since 9.0.0
*/
// eslint-disable-next-line @typescript-eslint/naming-convention
export class KHR_materials_volume_scatter {
/**
* @internal
*/
constructor(loader) {
/**
* The name of this extension.
*/
this.name = NAME;
/**
* Defines a number that determines the order the extensions are applied.
*/
this.order = 172;
this._loader = loader;
this.enabled = this._loader.isExtensionUsed(NAME);
if (this.enabled) {
// We need to disable instance usage because the attenuation factor depends on the node scale of each individual mesh
this._loader._disableInstancedMesh++;
}
}
/** @internal */
dispose() {
if (this.enabled) {
this._loader._disableInstancedMesh--;
}
this._loader = null;
}
/**
* @internal
*/
// eslint-disable-next-line no-restricted-syntax
loadMaterialPropertiesAsync(context, material, babylonMaterial) {
return GLTFLoader.LoadExtensionAsync(context, material, this.name, async (extensionContext, extension) => {
const promises = new Array();
promises.push(this._loader.loadMaterialPropertiesAsync(context, material, babylonMaterial));
promises.push(this._loadVolumePropertiesAsync(extensionContext, material, babylonMaterial, extension));
// eslint-disable-next-line github/no-then
return await Promise.all(promises).then(() => { });
});
}
// eslint-disable-next-line @typescript-eslint/promise-function-async, no-restricted-syntax
_loadVolumePropertiesAsync(context, material, babylonMaterial, extension) {
const adapter = this._loader._getOrCreateMaterialAdapter(babylonMaterial);
// If transparency isn't enabled already, this extension shouldn't do anything.
// i.e. it requires either the KHR_materials_transmission or KHR_materials_diffuse_transmission extensions.
// Additionally, this already needs to be a volumetric material to apply this extension.
if ((adapter.transmissionWeight === 0 && adapter.subsurfaceWeight === 0) || adapter.geometryThinWalled) {
return Promise.resolve();
}
const scatterColor = extension.multiscatterColorFactor !== undefined && extension.multiscatterColorFactor.length == 3 ? Color3.FromArray(extension.multiscatterColorFactor) : Color3.Black();
const scatterAnisotropy = extension.scatterAnisotropy !== undefined ? extension.scatterAnisotropy : 0;
// If diffuse_transmission, apply props to subsurface
// If transmission, apply props to transmission
// Load texture if present
let texturePromise = Promise.resolve(null);
if (extension.multiscatterColorTexture) {
extension.multiscatterColorTexture.nonColorData = true;
texturePromise = this._loader.loadTextureInfoAsync(`${context}/multiscatterColorTexture`, extension.multiscatterColorTexture, (texture) => {
texture.name = `${babylonMaterial.name} (Scatter Color)`;
if (adapter.transmissionWeight > 0) {
adapter.transmissionScatterTexture = texture;
}
if (adapter.subsurfaceWeight > 0) {
adapter.subsurfaceColorTexture = texture;
}
});
}
const extinctionCoefficient = new Vector3(-Math.log(adapter.transmissionColor.r), -Math.log(adapter.transmissionColor.g), -Math.log(adapter.transmissionColor.b));
extinctionCoefficient.scaleInPlace(1 / Math.max(adapter.transmissionDepth, 0.000001));
// In glTF, both the translucency volume and subsurface volume use the same input parameters.
// We'll apply them to both, as appropriate.
if (adapter.transmissionWeight > 0) {
const singleScatterAlbedo = multiScatterToSingleScatterAlbedo(scatterColor);
const scatteringCoefficient = extinctionCoefficient.multiply(singleScatterAlbedo);
// The scattering coefficient in OpenPBR is defined as per unit distance, so we need to scale it back up by the depth.
scatteringCoefficient.scaleInPlace(adapter.transmissionDepth);
adapter.transmissionScatter.set(scatteringCoefficient.x, scatteringCoefficient.y, scatteringCoefficient.z);
adapter.transmissionScatterAnisotropy = scatterAnisotropy;
}
// Subsurface volume
if (adapter.subsurfaceWeight > 0) {
adapter.subsurfaceScatterAnisotropy = scatterAnisotropy;
adapter.subsurfaceColor = scatterColor;
const mfp = new Vector3(extinctionCoefficient.x !== 0 ? 1.0 / extinctionCoefficient.x : 1.0, extinctionCoefficient.y !== 0 ? 1.0 / extinctionCoefficient.y : 1.0, extinctionCoefficient.z !== 0 ? 1.0 / extinctionCoefficient.z : 1.0);
adapter.subsurfaceRadius = Math.max(mfp.x, mfp.y, mfp.z);
adapter.subsurfaceRadiusScale = new Color3(mfp.x / adapter.subsurfaceRadius, mfp.y / adapter.subsurfaceRadius, mfp.z / adapter.subsurfaceRadius);
}
// eslint-disable-next-line github/no-then
return texturePromise.then(() => { });
}
}
unregisterGLTFExtension(NAME);
registerGLTFExtension(NAME, true, (loader) => new KHR_materials_volume_scatter(loader));
//# sourceMappingURL=KHR_materials_volume_scatter.js.map