Implement PBR anisotropy per KHR_materials_anisotropy.

Cargo.toml

@@ -3117,6 +3117,18 @@ description = "Demonstrates volumetric fog and lighting"
 category = "3D Rendering"
 wasm = true
 
+[[example]]
+name = "anisotropy"
+path = "examples/3d/anisotropy.rs"
+doc-scrape-examples = true
+required-features = ["jpeg"]
+
+[package.metadata.example.anisotropy]
+name = "Anisotropy"
+description = "Displays an example model with anisotropy"
+category = "3D Rendering"
+wasm = false
+
 [profile.wasm-release]
 inherits = "release"
 opt-level = "z"

assets/models/AnisotropyBarnLamp/AnisotropyBarnLamp.gltf

@@ -0,0 +1,350 @@
+{
+  "asset": {
+    "version": "2.0",
+    "generator": "3ds Max, Max2Babylon, Visual Studio Code, glTF Tools",
+    "copyright": "(c) 2023 Wayfair, model and textures by Eric Chadwick, CC BY 4.0."
+  },
+  "extensionsUsed": [
+    "KHR_materials_anisotropy",
+    "KHR_materials_clearcoat",
+    "KHR_materials_emissive_strength",
+    "KHR_materials_transmission",
+    "KHR_materials_volume"
+  ],
+  "scene": 0,
+  "scenes": [
+    {
+      "nodes": [
+        0,
+        1,
+        2
+      ]
+    }
+  ],
+  "nodes": [
+    {
+      "mesh": 0,
+      "name": "Lamp Metal"
+    },
+    {
+      "mesh": 1,
+      "name": "Lamp Filament"
+    },
+    {
+      "mesh": 2,
+      "name": "Lamp Glass"
+    }
+  ],
+  "meshes": [
+    {
+      "primitives": [
+        {
+          "attributes": {
+            "POSITION": 1,
+            "TANGENT": 2,
+            "NORMAL": 3,
+            "TEXCOORD_0": 4
+          },
+          "indices": 0,
+          "material": 0
+        }
+      ],
+      "name": "Lamp Metal"
+    },
+    {
+      "primitives": [
+        {
+          "attributes": {
+            "POSITION": 6,
+            "NORMAL": 7
+          },
+          "indices": 5,
+          "material": 1
+        }
+      ],
+      "name": "Lamp Filament"
+    },
+    {
+      "primitives": [
+        {
+          "attributes": {
+            "POSITION": 9,
+            "NORMAL": 10
+          },
+          "indices": 8,
+          "material": 2
+        }
+      ],
+      "name": "Lamp Glass"
+    }
+  ],
+  "accessors": [
+    {
+      "bufferView": 0,
+      "componentType": 5123,
+      "count": 25257,
+      "type": "SCALAR",
+      "name": "accessorIndices"
+    },
+    {
+      "bufferView": 1,
+      "componentType": 5126,
+      "count": 6803,
+      "max": [
+        0.08619007,
+        0.056946706,
+        0.226538792
+      ],
+      "min": [
+        -0.104619145,
+        -0.172301471,
+        -2.43595832E-06
+      ],
+      "type": "VEC3",
+      "name": "accessorPositions"
+    },
+    {
+      "bufferView": 2,
+      "componentType": 5126,
+      "count": 6803,
+      "type": "VEC4",
+      "name": "accessorTangents"
+    },
+    {
+      "bufferView": 1,
+      "byteOffset": 81636,
+      "componentType": 5126,
+      "count": 6803,
+      "type": "VEC3",
+      "name": "accessorNormals"
+    },
+    {
+      "bufferView": 3,
+      "componentType": 5126,
+      "count": 6803,
+      "type": "VEC2",
+      "name": "accessorUVs"
+    },
+    {
+      "bufferView": 0,
+      "byteOffset": 50516,
+      "componentType": 5123,
+      "count": 840,
+      "type": "SCALAR",
+      "name": "accessorIndices"
+    },
+    {
+      "bufferView": 1,
+      "byteOffset": 163272,
+      "componentType": 5126,
+      "count": 140,
+      "max": [
+        8.701398E-05,
+        -0.12128906,
+        0.142439723
+      ],
+      "min": [
+        -0.0193775147,
+        -0.170719177,
+        0.122564256
+      ],
+      "type": "VEC3",
+      "name": "accessorPositions"
+    },
+    {
+      "bufferView": 1,
+      "byteOffset": 164952,
+      "componentType": 5126,
+      "count": 140,
+      "type": "VEC3",
+      "name": "accessorNormals"
+    },
+    {
+      "bufferView": 0,
+      "byteOffset": 52196,
+      "componentType": 5123,
+      "count": 4512,
+      "type": "SCALAR",
+      "name": "accessorIndices"
+    },
+    {
+      "bufferView": 1,
+      "byteOffset": 166632,
+      "componentType": 5126,
+      "count": 769,
+      "max": [
+        0.01725974,
+        -0.0980222151,
+        0.15841879
+      ],
+      "min": [
+        -0.03568878,
+        -0.198292032,
+        0.106095724
+      ],
+      "type": "VEC3",
+      "name": "accessorPositions"
+    },
+    {
+      "bufferView": 1,
+      "byteOffset": 175860,
+      "componentType": 5126,
+      "count": 769,
+      "type": "VEC3",
+      "name": "accessorNormals"
+    }
+  ],
+  "bufferViews": [
+    {
+      "buffer": 0,
+      "byteLength": 61220,
+      "name": "bufferViewScalar",
+      "target": 34963
+    },
+    {
+      "buffer": 0,
+      "byteOffset": 61220,
+      "byteLength": 185088,
+      "byteStride": 12,
+      "name": "bufferViewFloatVec3",
+      "target": 34962
+    },
+    {
+      "buffer": 0,
+      "byteOffset": 246308,
+      "byteLength": 108848,
+      "byteStride": 16,
+      "name": "bufferViewFloatVec4",
+      "target": 34962
+    },
+    {
+      "buffer": 0,
+      "byteOffset": 355156,
+      "byteLength": 54424,
+      "byteStride": 8,
+      "name": "bufferViewFloatVec2",
+      "target": 34962
+    }
+  ],
+  "buffers": [
+    {
+      "uri": "AnisotropyBarnLamp.bin",
+      "byteLength": 409580
+    }
+  ],
+  "materials": [
+    {
+      "name": "Lamp Metal",
+      "pbrMetallicRoughness": {
+        "baseColorTexture": {
+          "index": 2
+        },
+        "metallicRoughnessTexture": {
+          "index": 1
+        }
+      },
+      "normalTexture": {
+        "index": 0
+      },
+      "occlusionTexture": {
+        "index": 1
+      },
+      "extensions": {
+        "KHR_materials_anisotropy": {
+          "anisotropyStrength": 1,
+          "anisotropyRotation": 0,
+          "anisotropyTexture": {
+            "index": 3
+          }
+        },
+        "KHR_materials_clearcoat": {
+          "clearcoatFactor": 0.25,
+          "clearcoatRoughnessFactor": 0.15,
+          "clearcoatNormalTexture": {
+            "index": 0
+          }
+        }
+      }
+    },
+    {
+      "name": "Lamp Filament",
+      "pbrMetallicRoughness": {
+        "baseColorFactor": [
+          0.09,
+          0.09,
+          0.09,
+          1
+        ],
+        "metallicFactor": 0,
+        "roughnessFactor": 0.7
+      },
+      "emissiveFactor": [
+        1,
+        0.5,
+        0.25
+      ],
+      "extensions": {
+        "KHR_materials_emissive_strength": {
+          "emissiveStrength": 25
+        }
+      }
+    },
+    {
+      "name": "Lamp Glass",
+      "pbrMetallicRoughness": {
+        "metallicFactor": 0,
+        "roughnessFactor": 0
+      },
+      "extensions": {
+        "KHR_materials_transmission": {
+          "transmissionFactor": 1
+        },
+        "KHR_materials_volume": {
+          "thicknessFactor": 0.01
+        }
+      }
+    }
+  ],
+  "textures": [
+    {
+      "sampler": 0,
+      "source": 0,
+      "name": "AnisotropyBarnLamp_normalbump.ktx2"
+    },
+    {
+      "sampler": 0,
+      "source": 1,
+      "name": "AnisotropyBarnLamp_occlusionroughnessmetal.ktx2"
+    },
+    {
+      "sampler": 0,
+      "source": 2,
+      "name": "AnisotropyBarnLamp_basecolor.jpeg"
+    },
+    {
+      "sampler": 0,
+      "source": 3,
+      "name": "AnisotropyBarnLamp_anisotropy.ktx2"
+    }
+  ],
+  "images": [
+    {
+      "uri": "AnisotropyBarnLamp_normalbump.ktx2"
+    },
+    {
+      "uri": "AnisotropyBarnLamp_occlusionroughnessmetal.ktx2"
+    },
+    {
+      "uri": "AnisotropyBarnLamp_basecolor.jpeg"
+    },
+    {
+      "uri": "AnisotropyBarnLamp_anisotropy.ktx2"
+    }
+  ],
+  "samplers": [
+    {
+      "magFilter": 9729,
+      "minFilter": 9987
+    }
+  ]
+}

assets/shaders/array_texture.wgsl

@@ -42,12 +42,12 @@ fn fragment(
 
 #ifdef VERTEX_TANGENTS
     let Nt = textureSampleBias(pbr_bindings::normal_map_texture, pbr_bindings::normal_map_sampler, mesh.uv, view.mip_bias).rgb;
+    let TBN = fns::calculate_tbn_mikktspace(mesh.world_normal, mesh.world_tangent);
     pbr_input.N = fns::apply_normal_mapping(
         pbr_input.material.flags,
-        mesh.world_normal,
+        TBN,
         double_sided,
         is_front,
-        mesh.world_tangent,
         Nt,
         view.mip_bias,
     );