gpu-curtains/dist/esm/core/shaders/chunks/fragment/body/get-IBL-volume-refraction.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.

//#region src/core/shaders/chunks/fragment/body/get-IBL-volume-refraction.ts
/**
* Apply transmission volume refraction to `totalDiffuse` light component if applicable.
* @param parameters - Parameters to use to apply transmission volume refraction.
* @param parameters.transmissionBackgroundTexture - {@link ShaderTextureDescriptor | Transmission background texture descriptor} to use for transmission if any.
* @param parameters.transmissiveInputColorSpace - Whether the opaque objects sampled by the transmission texture have been drawn in `linear` or `srgb` color space. Default to `srgb`.
* @param parameters.transmissiveInputToneMapping - The tone mapping applied to the opaque objects sampled by the transmission texture, if any. Default to `Khronos`.
* @param parameters.extensionsUsed - {@link types/gltf/GLTFExtensions.GLTFExtensionsUsed | glTF extensions used} by the material for specifing shading if any.
* @returns - A string with transmission volume refraction applied to `totalDiffuse` light component.
*/
const getIBLVolumeRefraction = ({ transmissionBackgroundTexture = null, transmissiveInputColorSpace = "srgb", transmissiveInputToneMapping = "Khronos", extensionsUsed = [] }) => {
	const iblVolumeRefractionFunction = extensionsUsed.includes("KHR_materials_dispersion") ? "getIBLVolumeRefractionWithDispersion" : "getIBLVolumeRefraction";
	const transmissiveToneMapping = [
		false,
		"Khronos",
		"Reinhard",
		"Cineon"
	].findIndex((t) => t === transmissiveInputToneMapping);
	return transmissionBackgroundTexture ? `
  var transmissionAlpha: f32 = 1.0;

  let isTransmissiveLinear: bool = ${transmissiveInputColorSpace === "linear" ? "true" : "false"};
  let transmissiveToneMapping: u32 = ${transmissiveToneMapping};
  
  var transmitted: vec4f = ${iblVolumeRefractionFunction}(
    normal,
    viewDirection,
    roughness, 
    diffuseContribution,
    fab,
    specularColorBlended,
    specularF90,
    worldPosition,
    modelScale,
    camera.view,
    camera.projection,
    dispersion,
    ior,
    thickness,
    attenuationColor,
    attenuationDistance,
    isTransmissiveLinear,
    transmissiveToneMapping,
    ${transmissionBackgroundTexture.texture.options.name},
    ${transmissionBackgroundTexture.sampler.name},
  );
  
  transmissionAlpha = mix( transmissionAlpha, transmitted.a, transmission );
  
  totalDiffuse = mix(totalDiffuse, transmitted.rgb, transmission);
  outputColor.a *= transmissionAlpha;` : "";
};
//#endregion
export { getIBLVolumeRefraction };