Same as #161

lib/loadObj.js

@@ -78,6 +78,7 @@ function loadObj(objPath, options) {
     var node;
     var mesh;
     var primitive;
+    var activeMaterial;
 
     // All nodes seen in the obj
     var nodes = [];
@@ -125,6 +126,7 @@ function loadObj(objPath, options) {
 
     function addPrimitive() {
         primitive = new Primitive();
+        primitive.material = activeMaterial;
         mesh.primitives.push(primitive);
 
         // Clear the vertex cache for each new primitive
@@ -132,22 +134,42 @@ function loadObj(objPath, options) {
         vertexCount = 0;
     }
 
-    function useMaterial(name) {
-        // Look to see if this material has already been used by a primitive in the mesh
-        var material = getName(name);
+    function reusePrimitive(callback) {
         var primitives = mesh.primitives;
         var primitivesLength = primitives.length;
         for (var i = 0; i < primitivesLength; ++i) {
-            if (primitives[i].material === material) {
-                primitive = primitives[i];
-                clearVertexCache();
-                vertexCount = primitive.positions.length / 3;
-                return;
+            if (primitives[i].material === activeMaterial) {
+                if (!defined(callback) || callback(primitives[i])) {
+                    primitive = primitives[i];
+                    clearVertexCache();
+                    vertexCount = primitive.positions.length / 3;
+                    return;
+                }
             }
         }
-        // Add a new primitive with this material
         addPrimitive();
-        primitive.material = getName(name);
+    }
+
+    function useMaterial(name) {
+        activeMaterial = getName(name);
+        reusePrimitive();
+    }
+
+    function faceAndPrimitiveMatch(uvs, normals, primitive) {
+        var faceHasUvs = uvs[0].length > 0;
+        var faceHasNormals = normals[0].length > 0;
+        var primitiveHasUvs = primitive.uvs.length > 0;
+        var primitiveHasNormals = primitive.normals.length > 0;
+        return primitiveHasUvs === faceHasUvs && primitiveHasNormals === faceHasNormals;
+    }
+
+    function checkPrimitive(uvs, normals) {
+        var firstFace = primitive.indices.length === 0;
+        if (!firstFace && !faceAndPrimitiveMatch(uvs, normals, primitive)) {
+            reusePrimitive(function(primitive) {
+                return faceAndPrimitiveMatch(uvs, normals, primitive);
+            });
+        }
     }
 
     function getOffset(a, attributeData, components) {
@@ -269,16 +291,7 @@ function loadObj(objPath, options) {
     function addFace(vertices, positions, uvs, normals) {
         var i;
         var isWindingCorrect;
-
-        var firstFace = primitive.indices.length === 0;
-        var faceHasUvs = uvs[0].length > 0;
-        var faceHasNormals = normals[0].length > 0;
-        var primitiveHasUvs = primitive.uvs.length > 0;
-        var primitiveHasNormals = primitive.normals.length > 0;
-        if (!firstFace && (faceHasUvs !== primitiveHasUvs || faceHasNormals !== primitiveHasNormals)) {
-            // Discard faces that don't use the same attributes
-            return;
-        }
+        checkPrimitive(uvs, normals);
 
         if (vertices.length === 3) {
             isWindingCorrect = checkWindingCorrect(positions[0], positions[1], positions[2], normals[0]);
@@ -347,10 +360,12 @@ function loadObj(objPath, options) {
             positions.push(position.y);
             positions.push(position.z);
         } else if ((result = normalPattern.exec(line) ) !== null) {
-            var normal = scratchCartesian;
-            normal.x = parseFloat(result[1]);
-            normal.y = parseFloat(result[2]);
-            normal.z = parseFloat(result[3]);
+            var normal = Cartesian3.fromElements(parseFloat(result[1]), parseFloat(result[2]), parseFloat(result[3]), scratchNormal);
+            if (Cartesian3.equals(normal, Cartesian3.ZERO)) {
+                Cartesian3.clone(Cartesian3.UNIT_Z, normal);
+            } else {
+                Cartesian3.normalize(normal, normal);
+            }
             if (defined(axisTransform)) {
                 Matrix4.multiplyByPointAsVector(axisTransform, normal, normal);
             }
@@ -375,7 +390,9 @@ function loadObj(objPath, options) {
                     faceUvs.push(result[2]);
                     faceNormals.push(result[3]);
                 }
-                addFace(faceVertices, facePositions, faceUvs, faceNormals);
+                if (faceVertices.length > 2) {
+                    addFace(faceVertices, facePositions, faceUvs, faceNormals);
+                }
 
                 faceVertices.length = 0;
                 facePositions.length = 0;
@@ -398,17 +415,20 @@ function loadObj(objPath, options) {
             uvs = undefined;
 
             // Load materials and images
-            return finishLoading(nodes, mtlPaths, objPath, options);
+            return finishLoading(nodes, mtlPaths, objPath, defined(activeMaterial), options);
         });
 }
 
-function finishLoading(nodes, mtlPaths, objPath, options) {
+function finishLoading(nodes, mtlPaths, objPath, usesMaterials, options) {
     nodes = cleanNodes(nodes);
     if (nodes.length === 0) {
         return Promise.reject(new RuntimeError(objPath + ' does not have any geometry data'));
     }
     return loadMaterials(mtlPaths, objPath, options)
         .then(function(materials) {
+            if (materials.length > 0 && !usesMaterials) {
+                assignDefaultMaterial(nodes, materials, usesMaterials);
+            }
             var imagePaths = getImagePaths(materials);
             return loadImages(imagePaths, objPath, options)
                 .then(function(images) {
@@ -494,6 +514,23 @@ function getImagePaths(materials) {
     return Object.keys(imagePaths);
 }
 
+function assignDefaultMaterial(nodes, materials) {
+    var defaultMaterial = materials[0].name;
+    var nodesLength = nodes.length;
+    for (var i = 0; i < nodesLength; ++i) {
+        var meshes = nodes[i].meshes;
+        var meshesLength = meshes.length;
+        for (var j = 0; j < meshesLength; ++j) {
+            var primitives = meshes[j].primitives;
+            var primitivesLength = primitives.length;
+            for (var k = 0; k < primitivesLength; ++k) {
+                var primitive = primitives[k];
+                primitive.material = defaultValue(primitive.material, defaultMaterial);
+            }
+        }
+    }
+}
+
 function removeEmptyMeshes(meshes) {
     return meshes.filter(function(mesh) {
         // Remove empty primitives

specs/lib/loadObjSpec.js

@@ -417,11 +417,15 @@ describe('loadObj', function() {
             }), done).toResolve();
     });
 
-    it('discards faces that don\'t use the same attributes as other faces in the primitive', function(done) {
+    it('separates faces that don\'t use the same attributes as other faces in the primitive', function(done) {
         expect(loadObj(objMixedAttributesUrl, defaultOptions)
             .then(function(data) {
-                var primitive = getPrimitives(data)[0];
-                expect(primitive.indices.length).toBe(18); // 3 faces removed
+                var primitives = getPrimitives(data);
+                expect(primitives.length).toBe(4);
+                expect(primitives[0].indices.length).toBe(18); // 6 faces
+                expect(primitives[1].indices.length).toBe(6); // 2 faces
+                expect(primitives[2].indices.length).toBe(6); // 2 faces
+                expect(primitives[3].indices.length).toBe(6); // 2 faces
             }), done).toResolve();
     });