Validate clearcoat normal texture texcoords (#225)

Author: lexaknyazev

ISSUES.md

@@ -42,6 +42,7 @@
 |INVALID_EXTENSION_NAME_FORMAT|Extension name has invalid format.|Warning|
 |INVALID_GL_VALUE|Invalid value `%1` for GL type '`%2`'.|Error|
 |KHR_LIGHTS_PUNCTUAL_LIGHT_SPOT_ANGLES|outerConeAngle (`%2`) is less than or equal to innerConeAngle (`%1`).|Error|
+|KHR_MATERIALS_CLEARCOAT_CLEARCOAT_NORMAL_TEXTURE_TEXCOORD|Normal and clearcoat normal textures should use the same texture coords.|Warning|
 |KHR_MATERIALS_DISPERSION_NO_VOLUME|The dispersion extension needs to be combined with the volume extension.|Warning|
 |KHR_MATERIALS_EMISSIVE_STRENGTH_ZERO_FACTOR|Emissive strength has no effect when the emissive factor is zero or undefined.|Warning|
 |KHR_MATERIALS_IRIDESCENCE_THICKNESS_RANGE_INVALID|Thickness maximum must be greater than or equal to the thickness minimum.|Error|

lib/src/errors.dart

@@ -489,6 +489,13 @@ class SemanticError extends IssueType {
       (args) => 'outerConeAngle (${args[1]}) is less than or equal to '
           'innerConeAngle (${args[0]}).');
 
+  static final SemanticError
+      khrMaterialsClearcoatClearcoatNormalTextureTexCoord = SemanticError._(
+          'KHR_MATERIALS_CLEARCOAT_CLEARCOAT_NORMAL_TEXTURE_TEXCOORD',
+          (args) => 'Normal and clearcoat normal textures '
+              'should use the same texture coords.',
+          Severity.Warning);
+
   static final SemanticError khrMaterialsDispersionNoVolume = SemanticError._(
       'KHR_MATERIALS_DISPERSION_NO_VOLUME',
       (args) => 'The dispersion extension needs to be combined with '

lib/src/ext/KHR_materials_clearcoat/khr_materials_clearcoat.dart

@@ -97,6 +97,20 @@ class KhrMaterialsClearcoat extends GltfProperty {
     if (clearcoatNormalTexture != null) {
       context.path.add(CLEARCOAT_NORMAL_TEXTURE);
       clearcoatNormalTexture.link(gltf, context);
+
+      Object o = this;
+      while (o != null) {
+        o = context.owners[o];
+        if (o is Material) {
+          final normalTexture = o.normalTexture;
+          if (normalTexture != null &&
+              normalTexture.texCoord != clearcoatNormalTexture.texCoord) {
+            context.addIssue(SemanticError
+                .khrMaterialsClearcoatClearcoatNormalTextureTexCoord);
+          }
+          break;
+        }
+      }
       context.path.removeLast();
     }
   }

test/ext/KHR_materials_clearcoat/assets.json

@@ -3,6 +3,7 @@
         "name": "material.KHR_materials_clearcoat",
         "tests": {
             "custom_property.gltf": "Custom property",
+            "different_texcoords.gltf": "Normal and clearcoat normal textures with different texcoords",
             "no_tangent_space.gltf": "No tangent space",
             "unexpected_extension.gltf": "Unexpected extension object location",
             "valid.gltf": "Valid",

test/ext/KHR_materials_clearcoat/data/material/different_texcoords.gltf

@@ -0,0 +1,28 @@
+{
+    "asset": {
+        "version": "2.0"
+    },
+    "extensionsUsed": [
+        "KHR_materials_clearcoat"
+    ],
+    "materials": [
+        {
+            "normalTexture": {
+                "index": 0
+            },
+            "extensions": {
+                "KHR_materials_clearcoat": {
+                    "clearcoatNormalTexture": {
+                        "index": 1,
+                        "texCoord": 1
+                    }
+                }
+            }
+        }
+    ],
+    "textures": [
+        {
+        }, {
+        }
+    ]
+}

test/ext/KHR_materials_clearcoat/data/material/different_texcoords.gltf.report.json

@@ -0,0 +1,44 @@
+{
+    "uri": "test/ext/KHR_materials_clearcoat/data/material/different_texcoords.gltf",
+    "mimeType": "model/gltf+json",
+    "validatorVersion": "2.0.0-dev.3.10",
+    "issues": {
+        "numErrors": 0,
+        "numWarnings": 1,
+        "numInfos": 1,
+        "numHints": 0,
+        "messages": [
+            {
+                "code": "KHR_MATERIALS_CLEARCOAT_CLEARCOAT_NORMAL_TEXTURE_TEXCOORD",
+                "message": "Normal and clearcoat normal textures should use the same texture coords.",
+                "severity": 1,
+                "pointer": "/materials/0/extensions/KHR_materials_clearcoat/clearcoatNormalTexture"
+            },
+            {
+                "code": "UNUSED_OBJECT",
+                "message": "This object may be unused.",
+                "severity": 2,
+                "pointer": "/materials/0"
+            }
+        ],
+        "truncated": false
+    },
+    "info": {
+        "version": "2.0",
+        "extensionsUsed": [
+            "KHR_materials_clearcoat"
+        ],
+        "animationCount": 0,
+        "materialCount": 1,
+        "hasMorphTargets": false,
+        "hasSkins": false,
+        "hasTextures": true,
+        "hasDefaultScene": false,
+        "drawCallCount": 0,
+        "totalVertexCount": 0,
+        "totalTriangleCount": 0,
+        "maxUVs": 0,
+        "maxInfluences": 0,
+        "maxAttributes": 0
+    }
+}