Merge pull request #1949 from AnalyticalGraphicsInc/gltf-8

Support for glTF 0.8

CHANGES.md

@@ -79,6 +79,7 @@ Change Log
   * Removed `ScreenSpaceCameraController.ellipsoid`. The behavior that depended on the ellipsoid is now determined based on the scene state.
   * Sandcastle examples now automatically wrap the example code in RequireJS boilerplate.  To upgrade any custom examples, copy the code into an existing example (such as Hello World) and save a new file.
   * Replaced `PerspectiveFrustum.fovy` with `PerspectiveFrustum.fov` which will change the field of view angle in either the x or y direction depending on the aspect ratio.
+  * Updated the [Model Converter](http://cesiumjs.org/convertmodel.html) and `Model` to support [glTF 0.8](https://github.com/KhronosGroup/glTF/blob/schema-8/specification/README.md).  See the [forum post](https://groups.google.com/forum/#!topic/cesium-dev/KNl2K3Cazno) for full details.
 * Added northUpEast transform to help support display of glTF models because Y is their up axis.
 * Cesium can now render an unlimited number of imagery layers, no matter how few texture units are supported by the hardware.
 * Added `czm_octDecode` and `czm_signNotZero` builtin functions.

Source/Scene/ModelAnimationCache.js

@@ -5,14 +5,14 @@ define([
         '../Core/LinearSpline',
         '../Core/Quaternion',
         '../Core/QuaternionSpline',
-        './ModelTypes'
+        './getModelAccessor'
     ], function(
         Cartesian3,
         defined,
         LinearSpline,
         Quaternion,
         QuaternionSpline,
-        ModelTypes) {
+        getModelAccessor) {
     "use strict";
     /*global WebGLRenderingContext*/
 
@@ -34,7 +34,7 @@ define([
         var buffer = buffers[bufferView.buffer];
 
         var byteOffset = bufferView.byteOffset + accessor.byteOffset;
-        var byteLength = accessor.count * ModelTypes[accessor.type].componentsPerAttribute;
+        var byteLength = accessor.count * getModelAccessor(accessor).componentsPerAttribute;
 
         return model.basePath + buffer.path + ':' + byteOffset + ':' + byteLength;
     }
@@ -53,22 +53,23 @@ define([
 
             var bufferView = bufferViews[accessor.bufferView];
 
+            var componentType = accessor.componentType;
             var type = accessor.type;
             var count = accessor.count;
 
             // Convert typed array to Cesium types
-            var typedArray = ModelTypes[type].createArrayBufferView(buffers[bufferView.buffer], bufferView.byteOffset + accessor.byteOffset, accessor.count);
+            var typedArray = getModelAccessor(accessor).createArrayBufferView(buffers[bufferView.buffer], bufferView.byteOffset + accessor.byteOffset, count);
             var i;
 
-            if (type === WebGLRenderingContext.FLOAT) {
+            if ((componentType === WebGLRenderingContext.FLOAT) && (type === 'SCALAR')) {
                 values = typedArray;
             }
-            else if (type === WebGLRenderingContext.FLOAT_VEC3) {
+            else if ((componentType === WebGLRenderingContext.FLOAT) && (type === 'VEC3')) {
                 values = new Array(count);
                 for (i = 0; i < count; ++i) {
                     values[i] = Cartesian3.fromArray(typedArray, 3 * i);
                 }
-            } else if (type === WebGLRenderingContext.FLOAT_VEC4) {
+            } else if ((componentType === WebGLRenderingContext.FLOAT) && (type === 'VEC4')) {
                 values = new Array(count);
                 for (i = 0; i < count; ++i) {
                     var byteOffset = 4 * i;
@@ -106,21 +107,24 @@ define([
 
         if (!defined(spline)) {
             var times = parameterValues[sampler.input];
-            var output = model.gltf.accessors[animation.parameters[sampler.output]];
+            var accessor = model.gltf.accessors[animation.parameters[sampler.output]];
             var controlPoints = parameterValues[sampler.output];
 
 // GLTF_SPEC: https://github.com/KhronosGroup/glTF/issues/185
             if ((times.length === 1) && (controlPoints.length === 1)) {
                 spline = new ConstantSpline(controlPoints[0]);
             } else {
 // END GLTF_SPEC
+                var componentType = accessor.componentType;
+                var type = accessor.type;
+
                 if (sampler.interpolation === 'LINEAR') {
-                    if (output.type === WebGLRenderingContext.FLOAT_VEC3) {
+                    if ((componentType === WebGLRenderingContext.FLOAT) && (type === 'VEC3')) {
                         spline = new LinearSpline({
                             times : times,
                             points : controlPoints
                         });
-                    } else if (output.type === WebGLRenderingContext.FLOAT_VEC4) {
+                    } else if ((componentType === WebGLRenderingContext.FLOAT) && (type === 'VEC4')) {
                         spline = new QuaternionSpline({
                             times : times,
                             points : controlPoints

Source/Scene/getModelAccessor.js

@@ -0,0 +1,34 @@
+/*global define*/
+define([
+        '../Core/ComponentDatatype'
+    ], function(
+        ComponentDatatype) {
+    "use strict";
+
+    var ComponentsPerAttribute = {
+        'SCALAR' : 1,
+        'VEC2' : 2,
+        'VEC3' : 3,
+        'VEC4' : 4,
+        'MAT2' : 4,
+        'MAT3' : 9,
+        'MAT4' : 16
+    };
+
+    /**
+     * @private
+     */
+    var getModelAccessor = function(accessor) {
+        var componentDatatype = accessor.componentType;
+        var componentsPerAttribute = ComponentsPerAttribute[accessor.type];
+
+        return {
+            componentsPerAttribute : componentsPerAttribute,
+            createArrayBufferView : function(buffer, byteOffset, length) {
+                return ComponentDatatype.createArrayBufferView(componentDatatype, buffer, byteOffset, componentsPerAttribute * length);
+            }
+        };
+    };
+
+    return getModelAccessor;
+});