Load data for KHR_materials_anisotropy

Specs/Data/Models/glTF-2.0/AnisotropyRotationTest/LICENSE.md

@@ -0,0 +1,15 @@
+# LICENSE file for the model: Anisotropy Rotation Test
+
+All files in this directory tree are licensed as indicated below.
+
+- All files directly associated with the model including all text, image and binary files:
+
+  - [CC BY 4.0 International]("https://creativecommons.org/licenses/by/4.0/legalcode") [SPDX license identifier: "CC-BY-4.0"]
+
+- This file and all other metadocumentation files including "metadata.json":
+
+  - [Creative Commons Attribtution 4.0 International]("https://creativecommons.org/licenses/by/4.0/legalcode") [SPDX license identifier: "CC-BY-4.0"]
+
+Full license text of these licenses are available at the links above
+
+#### Generated by modelmetadata

Specs/Data/Models/glTF-2.0/AnisotropyRotationTest/README.md

@@ -0,0 +1,57 @@
+# Anisotropy Rotation Test
+
+## Tags
+
+[extension](../../Models-extension.md), [testing](../../Models-testing.md)
+
+## Extensions Used
+
+- KHR_materials_anisotropy
+
+## Summary
+
+This model tests rotational offsets for KHR_materials_anisotropy.
+
+## Operations
+
+- [Display](https://github.khronos.org/glTF-Sample-Viewer-Release/?model=https://raw.GithubUserContent.com/KhronosGroup/glTF-Sample-Assets/main/./Models/AnisotropyRotationTest/glTF-Binary/AnisotropyRotationTest.glb) in SampleViewer
+- [Download GLB](https://raw.GithubUserContent.com/KhronosGroup/glTF-Sample-Assets/main/./Models/AnisotropyRotationTest/glTF-Binary/AnisotropyRotationTest.glb)
+- [Model Directory](./)
+
+## Screenshot
+
+![screenshot](screenshot/screenshot-large.png)
+
+## Description
+
+This model tests rotational offsets for [`KHR_materials_anisotropy`](https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_materials_anisotropy). It has the following features:
+
+- Six of the meshes (2 on the bottom row, 2 in the middle, and 2 on the top row) are all "simple" anisotropy with material roughness extended horizontally along the mesh's `TANGENT` vectors.
+
+- One mesh in the lower-left marked "Tangents + Rotation" has a 30-degree clockwise tilt to the `TANGENT` vectors, and un-does this rotation using the `anisotropyRotation` parameter in radians equivalent to 30 degrees counter-clockwise. When the rotation is applied correctly, the anisotropy here should look the same as the neighboring meshes.
+
+- One mesh in the upper-left marked "Tangents + Texture" has the same 30-degree clockwise tilt to the `TANGENT` vectors, and un-does this rotation using the `anisotropyTexture` parameter with a 30-degree counter-clockwise tilt encoded in the texture. As before, when the rotation is applied correctly, the anisotropy here should look the same as the neighboring meshes.
+
+- One mesh in the lower-right marked "Tangents + Texture + Rotation" has again the same 30-degree clockwise tilt to the `TANGENT` vectors as the others. However this mesh uses a combination of 10 degrees from `anisotropyTexture` and 20 degrees (in radians) from `anisotropyRotation`, combining to create the 30-degree counter-clockwise tilt needed to make the anisotropy horizontal like the other meshes.
+
+- Finally, one mesh in the upper-right marked "Normal map of grooves" has no anisotropy applied at all. It has a (somewhat grainy) normal texture applied with a series of vertical grooves, intended to approximate the look of very coarse horizontal anisotropy. It will not look exactly the same as its neighbors, but a bright light source in the environment should still spread out horizontally like its neighbors.
+
+## IBL Example
+
+![IBL screenshot](screenshot/ibl-example.png)
+
+With a full IBL reflection environment, the model should show horizontal stretching. It may appear similar to the screenshot above.
+
+## Incorrect Rotation Example
+
+![rotation failure screenshot](screenshot/fail-example.png)
+
+In the above image, the six "Basic Anisotropy" meshes are correct. But on the left side, both the texture-based rotation and JSON-based rotation are incorrect, and in the lower-right, the combination of both is also incorrect. These test meshes use a 30-degree clockwise slant in the tangent vectors that is intended to be undone by a 30-degree counter-clockwise rotation in the material. However in this image, a 60-degree clockwise rotation is visible on all three of these meshes, indicating that the material rotated the opposite way.
+
+## Legal
+
+© 2023, Analytical Graphics, Inc.. [CC BY 4.0 International](https://creativecommons.org/licenses/by/4.0/legalcode)
+
+- Ed Mackey for Everything
+
+### Assembled by modelmetadata

Specs/Data/Models/glTF-2.0/AnisotropyRotationTest/metadata.json

@@ -0,0 +1,25 @@
+{
+    "version": 2,
+    "legal": [
+        {
+            "year": "2023",
+            "owner": "Analytical Graphics, Inc.",
+            "license": "CC-BY International 4.0",
+            "artist": "Ed Mackey",
+            "what": "Everything",
+            "licenseUrl": "https://creativecommons.org/licenses/by/4.0/legalcode",
+            "text": "CC BY 4.0 International",
+            "spdx": "CC-BY-4.0",
+            "icon": "https://licensebuttons.net/l/by/3.0/88x31.png"
+        }
+    ],
+    "tags": [
+        "extension",
+        "testing"
+    ],
+    "screenshot": "screenshot/screenshot.png",
+    "name": "Anisotropy Rotation Test",
+    "path": "./Models/AnisotropyRotationTest",
+    "summary": "This model tests rotational offsets for KHR_materials_anisotropy.",
+    "createReadme": true
+}

packages/engine/Source/Scene/GltfLoader.js

@@ -54,6 +54,7 @@ const {
   MetallicRoughness,
   SpecularGlossiness,
   Specular,
+  Anisotropy,
   Material,
 } = ModelComponents;
 
@@ -1559,12 +1560,34 @@ function loadSpecular(loader, specularInfo, frameState) {
       frameState
     );
   }
+  // TODO: if not defined, should we leave the default values?
   specular.specularFactor = specularFactor;
   specular.specularColorFactor = fromArray(Cartesian3, specularColorFactor);
 
   return specular;
 }
 
+function loadAnisotropy(loader, anisotropyInfo, frameState) {
+  const {
+    anisotropyStrength = Anisotropy.DEFAULT_ANISOTROPY_STRENGTH,
+    anisotropyRotation = Anisotropy.DEFAULT_ANISOTROPY_ROTATION,
+    anisotropyTexture,
+  } = anisotropyInfo;
+
+  const anisotropy = new Anisotropy();
+  if (defined(anisotropyTexture)) {
+    anisotropy.anisotropyTexture = loadTexture(
+      loader,
+      anisotropyTexture,
+      frameState
+    );
+  }
+  anisotropy.anisotropyStrength = anisotropyStrength;
+  anisotropy.anisotropyRotation = anisotropyRotation;
+
+  return anisotropy;
+}
+
 /**
  * Load textures and parse factors and flags for a glTF material
  *
@@ -1583,6 +1606,7 @@ function loadMaterial(loader, gltfMaterial, frameState) {
   );
   const pbrSpecularGlossiness = extensions.KHR_materials_pbrSpecularGlossiness;
   const pbrSpecular = extensions.KHR_materials_specular;
+  const pbrAnisotropy = extensions.KHR_materials_anisotropy;
   const pbrMetallicRoughness = gltfMaterial.pbrMetallicRoughness;
 
   material.unlit = defined(extensions.KHR_materials_unlit);
@@ -1594,6 +1618,7 @@ function loadMaterial(loader, gltfMaterial, frameState) {
       frameState
     );
   } else {
+    // TODO: should this branch exclude materials.unlit?
     if (defined(pbrMetallicRoughness)) {
       material.metallicRoughness = loadMetallicRoughness(
         loader,
@@ -1602,8 +1627,13 @@ function loadMaterial(loader, gltfMaterial, frameState) {
       );
     }
     if (defined(pbrSpecular)) {
+      // TODO: not compatible with materials.unlit
       material.specular = loadSpecular(loader, pbrSpecular, frameState);
     }
+    if (defined(pbrAnisotropy)) {
+      // TODO: not compatible with materials.unlit
+      material.anisotropy = loadAnisotropy(loader, pbrAnisotropy, frameState);
+    }
   }
 
   // Top level textures

packages/engine/Source/Scene/Model/MaterialPipelineStage.js

@@ -63,20 +63,19 @@ MaterialPipelineStage.process = function (
   // gltf-pipeline automatically creates a default material so this will always
   // be defined.
   const material = primitive.material;
-  const model = renderResources.model;
+  const { model, uniformMap, shaderBuilder } = renderResources;
 
   // Classification models only use position and feature ID attributes,
   // so textures should be disabled to avoid compile errors.
   const hasClassification = defined(model.classificationType);
   const disableTextures = hasClassification;
 
-  const uniformMap = renderResources.uniformMap;
-  const shaderBuilder = renderResources.shaderBuilder;
-
   // When textures are loaded incrementally, fall back to a default 1x1 texture
-  const defaultTexture = frameState.context.defaultTexture;
-  const defaultNormalTexture = frameState.context.defaultNormalTexture;
-  const defaultEmissiveTexture = frameState.context.defaultEmissiveTexture;
+  const {
+    defaultTexture,
+    defaultNormalTexture,
+    defaultEmissiveTexture,
+  } = frameState.context;
 
   processMaterialUniforms(
     material,
@@ -90,7 +89,7 @@ MaterialPipelineStage.process = function (
 
   if (defined(material.specularGlossiness)) {
     processSpecularGlossinessUniforms(
-      material,
+      material.specularGlossiness,
       uniformMap,
       shaderBuilder,
       defaultTexture,
@@ -102,15 +101,27 @@ MaterialPipelineStage.process = function (
       ModelUtility.supportedExtensions.KHR_materials_specular === true
     ) {
       processSpecularUniforms(
-        material,
+        material.specular,
+        uniformMap,
+        shaderBuilder,
+        defaultTexture,
+        disableTextures
+      );
+    }
+    if (
+      defined(material.anisotropy) &&
+      ModelUtility.supportedExtensions.KHR_materials_anisotropy === true
+    ) {
+      processAnisotropyUniforms(
+        material.anisotropy,
         uniformMap,
         shaderBuilder,
         defaultTexture,
         disableTextures
       );
     }
     processMetallicRoughnessUniforms(
-      material,
+      material.metallicRoughness,
       uniformMap,
       shaderBuilder,
       defaultTexture,
@@ -321,14 +332,23 @@ function processMaterialUniforms(
   }
 }
 
+/**
+ * Add uniforms and defines for the KHR_materials_pbrSpecularGlossiness extension
+ *
+ * @param {ModelComponents.SpecularGlossiness} specularGlossiness
+ * @param {Object<string, Function>} uniformMap The uniform map to modify.
+ * @param {ShaderBuilder} shaderBuilder
+ * @param {Texture} defaultTexture
+ * @param {boolean} disableTextures
+ * @private
+ */
 function processSpecularGlossinessUniforms(
-  material,
+  specularGlossiness,
   uniformMap,
   shaderBuilder,
   defaultTexture,
   disableTextures
 ) {
-  const { specularGlossiness } = material;
   const {
     diffuseTexture,
     diffuseFactor,
@@ -426,14 +446,23 @@ function processSpecularGlossinessUniforms(
   }
 }
 
+/**
+ * Add uniforms and defines for the KHR_materials_specular extension
+ *
+ * @param {ModelComponents.Specular} specular
+ * @param {Object<string, Function>} uniformMap The uniform map to modify.
+ * @param {ShaderBuilder} shaderBuilder
+ * @param {Texture} defaultTexture
+ * @param {boolean} disableTextures
+ * @private
+ */
 function processSpecularUniforms(
-  material,
+  specular,
   uniformMap,
   shaderBuilder,
   defaultTexture,
   disableTextures
 ) {
-  const { specular } = material;
   const {
     specularTexture,
     specularFactor,
@@ -511,14 +540,79 @@ function processSpecularUniforms(
   }
 }
 
+const scratchAnisotropy = new Cartesian3();
+
+/**
+ * Add uniforms and defines for the KHR_materials_anisotropy extension
+ *
+ * @param {ModelComponents.Anisotropy} anisotropy
+ * @param {Object<string, Function>} uniformMap The uniform map to modify.
+ * @param {ShaderBuilder} shaderBuilder
+ * @param {Texture} defaultTexture
+ * @param {boolean} disableTextures
+ * @private
+ */
+function processAnisotropyUniforms(
+  anisotropy,
+  uniformMap,
+  shaderBuilder,
+  defaultTexture,
+  disableTextures
+) {
+  const {
+    anisotropyStrength,
+    anisotropyRotation,
+    anisotropyTexture,
+  } = anisotropy;
+
+  shaderBuilder.addDefine(
+    "USE_ANISOTROPY",
+    undefined,
+    ShaderDestination.FRAGMENT
+  );
+
+  if (defined(anisotropyTexture) && !disableTextures) {
+    processTexture(
+      shaderBuilder,
+      uniformMap,
+      anisotropyTexture,
+      "u_anisotropyTexture",
+      "ANISOTROPY",
+      defaultTexture
+    );
+  }
+
+  // Pre-compute cos and sin of rotation, since they are the same for all fragments.
+  // Combine with strength as one vec3 uniform.
+  const anisotropyValues = Cartesian3.fromElements(
+    Math.cos(anisotropyRotation),
+    Math.sin(anisotropyRotation),
+    anisotropyStrength,
+    scratchAnisotropy
+  );
+  shaderBuilder.addUniform("vec3", "u_anisotropy", ShaderDestination.FRAGMENT);
+  uniformMap.u_anisotropy = function () {
+    return anisotropyValues;
+  };
+}
+
+/**
+ * Add uniforms and defines for the PBR metallic roughness model
+ *
+ * @param {ModelComponents.MetallicRoughness} metallicRoughness
+ * @param {Object<string, Function>} uniformMap The uniform map to modify.
+ * @param {ShaderBuilder} shaderBuilder
+ * @param {Texture} defaultTexture
+ * @param {boolean} disableTextures
+ * @private
+ */
 function processMetallicRoughnessUniforms(
-  material,
+  metallicRoughness,
   uniformMap,
   shaderBuilder,
   defaultTexture,
   disableTextures
 ) {
-  const metallicRoughness = material.metallicRoughness;
   shaderBuilder.addDefine(
     "USE_METALLIC_ROUGHNESS",
     undefined,