gpu-curtains/dist/esm/core/shaders/chunks/fragment/body/get-sheen.mjs

gpu-curtains is a 3D WebGPU rendering engine. It can be used as a standalone 3D engine, but also includes extra classes focused on mapping 3d objects to DOM elements; It allows users to synchronize values such as position, sizing, or scale between them.

import { getTextureSample } from "./get-texture-sample.mjs";
//#region src/core/shaders/chunks/fragment/body/get-sheen.ts
/**
* Set the `sheenRoughness` (`f32`) and `sheenColor` (`vec3f`) values from the material sheen variables and eventual sheen textures.
* @param parameters - Parameters used to set the `sheenRoughness` (`f32`) and `sheenColor` (`vec3f`) values.
* @param parameters.extensionsUsed - {@link PBRFragmentShaderInputParams.extensionsUsed | extensionsUsed} to check if sheen is enabled.
* @param parameters.sheenTexture - {@link ShaderTextureDescriptor | Sheen texture descriptor} (mixing both sheen color in the `RGB` channels and sheen roughness in the `A` channel) to use if any.
* @param parameters.sheenColorTexture - {@link ShaderTextureDescriptor | Sheen color texture descriptor} (using the `RGB` channels) to use if any.
* @param parameters.sheenRoughnessTexture - {@link ShaderTextureDescriptor | Sheen roughness texture descriptor} (using the `A` channel) to use if any.
* @returns - String with the `sheenRoughness` (`f32`) and `sheenColor` (`vec3f`) values set.
*/
const getSheen = ({ extensionsUsed = [], sheenTexture = null, sheenColorTexture = null, sheenRoughnessTexture = null } = {}) => {
	let sheen = `
  var sheenSpecularDirect: vec3f = vec3(0.0);
  var sheenSpecularIndirect: vec3f = vec3(0.0);`;
	if (!extensionsUsed.includes("KHR_materials_sheen")) return sheen;
	if (sheenTexture) {
		sheen += getTextureSample(sheenTexture, "sheen");
		sheen += `
  sheenColor = sheenColor * sheenSample.rgb;
  sheenRoughness = sheenRoughness * sheenSample.a;
    `;
	} else {
		if (sheenColorTexture) {
			sheen += getTextureSample(sheenColorTexture, "sheenColor");
			sheen += `
  sheenColor = sheenColor * sheenColorSample.rgb;
    `;
		}
		if (sheenRoughnessTexture) {
			sheen += getTextureSample(sheenRoughnessTexture, "sheenRoughness");
			sheen += `
  sheenRoughness = sheenRoughness * sheenRoughnessSample.a;
  `;
		}
	}
	sheen += `
  sheenRoughness = clamp(sheenRoughness, 0.0001, 1.0);`;
	return sheen;
};
//#endregion
export { getSheen };