Add default translation, rotation, scale to node targeted for animation

lib/ForEach.js

@@ -48,6 +48,11 @@ ForEach.animation = function(gltf, handler) {
     ForEach.topLevel(gltf, 'animations', handler);
 };
 
+ForEach.animationChannel = function(animation, handler) {
+    var channels = animation.channels;
+    ForEach.object(channels, handler);
+};
+
 ForEach.animationSampler = function(animation, handler) {
     var samplers = animation.samplers;
     if (defined(samplers)) {

lib/addDefaults.js

@@ -210,6 +210,34 @@ function addDefaultsFromTemplate(object, template) {
     }
 }
 
+function getAnimatedNodes(gltf) {
+    var nodes = {};
+    ForEach.animation(gltf, function(animation) {
+        ForEach.animationChannel(animation, function(channel) {
+            var target = channel.target;
+            var nodeId = target.node;
+            var path = target.path;
+            // Ignore animations that target 'weights'
+            if (path === 'translation' || path === 'rotation' || path === 'scale') {
+                nodes[nodeId] = true;
+            }
+        });
+    });
+    return nodes;
+}
+
+function addDefaultTransformToAnimatedNodes(gltf) {
+    var animatedNodes = getAnimatedNodes(gltf);
+    ForEach.node(gltf, function(node, id) {
+        if (defined(animatedNodes[id])) {
+            delete node.matrix;
+            node.translation = defaultValue(node.translation, [0.0, 0.0, 0.0]);
+            node.rotation = defaultValue(node.rotation, [0.0, 0.0, 0.0, 1.0]);
+            node.scale = defaultValue(node.scale, [1.0, 1.0, 1.0]);
+        }
+    });
+}
+
 var defaultMaterial = {
     values : {
         emission : [
@@ -475,6 +503,7 @@ function inferBufferViewTargets(gltf) {
 function addDefaults(gltf, options) {
     options = defaultValue(options, {});
     addDefaultsFromTemplate(gltf, gltfTemplate);
+    addDefaultTransformToAnimatedNodes(gltf);
     addDefaultMaterial(gltf);
     addDefaultTechnique(gltf);
     addDefaultByteOffsets(gltf);

specs/lib/addDefaultsSpec.js

@@ -383,4 +383,37 @@ describe('addDefaults', function() {
         expect(gltf.bufferViews[2].target).not.toBeDefined();
         expect(gltf.bufferViews[3].target).toEqual(WebGLConstants.ARRAY_BUFFER);
     });
+
+    it('Adds animation properties', function() {
+        var gltf = {
+            animations: [{
+                channels: [
+                    {
+                        sampler: 0,
+                        target: {
+                            node: 0,
+                            path: 'rotation'
+                        }
+                    }
+                ],
+                samplers: [{
+                    input: 0,
+                    output: 1
+                }]
+            }],
+            nodes: [
+                {
+                    mesh: 0
+                }
+            ]
+        };
+
+        addDefaults(gltf);
+        var node = gltf.nodes[0];
+        expect(node.translation).toEqual([0, 0, 0]);
+        expect(node.rotation).toEqual([0, 0, 0, 1]);
+        expect(node.scale).toEqual([1, 1, 1]);
+        expect(node.matrix).toBeUndefined();
+    });
+
 });