KHR_materials_common and KHR_binary_glTF compatibility

CHANGES.md

@@ -2,7 +2,7 @@ Change Log
 ==========
 
 ### 1.18 - 2016-02-01
-
+* Improved compatibility with glTF KHR_binary_glTF and KHR_materials_common extensions
 * Reduced the amount of CPU memory used by terrain by ~25% in Chrome.
 * Fixed a picking problem ([#3386](https://github.com/AnalyticalGraphicsInc/cesium/issues/3386)) that sometimes prevented objects being selected.
 * Added `Scene.useDepthPicking` to enable or disable picking using the depth buffer. [#3390](https://github.com/AnalyticalGraphicsInc/cesium/pull/3390)

CONTRIBUTORS.md

@@ -80,5 +80,6 @@ See [CONTRIBUTING.md](CONTRIBUTING.md) for details on how to contribute to Cesiu
 * [Tucker Tibbetts](https://github.com/cttibbetts)
 * [Eric Putnam](https://github.com/eputnam)
 * [Dmitriy Pushkov](https://github.com/ezze)
+* [Max Limper](https://github.com/mlimper)
 
 Also see [our contributors page](http://cesiumjs.org/contributors.html) for more information.

Source/Scene/Model.js

@@ -342,7 +342,7 @@ define([
                     // Binary glTF
                     var result = parseBinaryGltfHeader(gltf);
 
-                    // CESIUM_binary_glTF is from the beginning of the file but
+                    // CESIUM_binary_glTF is from the beginning of the file but the
                     // KHR_binary_glTF is from the beginning of the binary section
                     if (result.binaryOffset !== 0) {
                         gltf = gltf.subarray(result.binaryOffset);
@@ -975,7 +975,7 @@ define([
                     // Load binary glTF
                     var result = parseBinaryGltfHeader(array);
                     // CESIUM_binary_glTF is from the beginning of the file but
-                    //  KHR_binary_glTF is from the beginning of the binary section
+                    // KHR_binary_glTF is from the beginning of the binary section
                     if (result.binaryOffset !== 0) {
                         array = array.subarray(result.binaryOffset);
                     }
@@ -1148,7 +1148,9 @@ define([
             if (buffers.hasOwnProperty(id)) {
                 var buffer = buffers[id];
 
-                if (id === 'CESIUM_binary_glTF' || id === 'KHR_binary_glTF') {
+                // The extension 'KHR_binary_glTF' uses a special buffer entitled just 'binary_glTF'.
+                // The 'KHR_binary_glTF' check is for backwards compatibility with Cesium 1.15.
+                if (id === 'CESIUM_binary_glTF' || id === 'binary_glTF' || id === 'KHR_binary_glTF') {
                     // Buffer is the binary glTF file itself that is already loaded
                     var loadResources = model._loadResources;
                     loadResources.buffers[id] = model._cachedGltf.bgltf;

Source/Scene/modelMaterialsCommon.js

@@ -223,14 +223,17 @@ define([
         var lowerCase;
         var hasTexCoords = false;
         for(var name in parameterValues) {
-            if (parameterValues.hasOwnProperty(name)) {
-                var value = parameterValues[name];
+            //generate shader parameters for KHR_materials_common attributes
+            //(including a check, because some boolean flags should not be used as shader parameters)
+            if (parameterValues.hasOwnProperty(name) &&
+                name !== "transparent" && name !== "doubleSided") {
+                var valType = getKHRMaterialsCommonValueType(name, parameterValues[name]);
                 lowerCase = name.toLowerCase();
-                if (!hasTexCoords && (value.type === WebGLConstants.SAMPLER_2D)) {
+                if (!hasTexCoords && (valType === WebGLConstants.SAMPLER_2D)) {
                     hasTexCoords = true;
                 }
                 techniqueParameters[lowerCase] = {
-                    type: value.type
+                    type: valType
                 };
             }
         }
@@ -609,18 +612,64 @@ define([
         return techniqueId;
     }
 
+    function getKHRMaterialsCommonValueType(paramName, paramValue)
+    {
+        var value;
+
+        // for compatibility with old glb files, encoding materials using
+        // KHR_materials_common with explicit "type" / "value" members
+        if (defined(paramValue.value))
+        {
+            value = paramValue.value;
+        }
+        else
+        {
+            value = paramValue;
+        }
+
+        switch (paramName)
+        {
+            case "ambient" :
+                return WebGLConstants.FLOAT_VEC4;
+
+            case "diffuse" :
+                return (value instanceof String || typeof value === "string") ? WebGLConstants.SAMPLER_2D : WebGLConstants.FLOAT_VEC4;
+
+            case "emission" :
+                return (value instanceof String || typeof value === "string") ? WebGLConstants.SAMPLER_2D : WebGLConstants.FLOAT_VEC4;
+
+            case "specular" :
+                return (value instanceof String || typeof value === "string") ? WebGLConstants.SAMPLER_2D : WebGLConstants.FLOAT_VEC4;
+
+            case "shininess" :
+                return WebGLConstants.FLOAT;
+
+            case "transparency" :
+                return WebGLConstants.FLOAT;
+
+            // these two are usually not used directly within shaders,
+            // they are just added here for completeness
+            case "transparent" :
+                return WebGLConstants.BOOL;                
+            case "doubleSided" :
+                return WebGLConstants.BOOL;                
+        }
+    }
+
     function getTechniqueKey(khrMaterialsCommon) {
         var techniqueKey = '';
-         techniqueKey += 'technique:' + khrMaterialsCommon.technique + ';';
+        techniqueKey += 'technique:' + khrMaterialsCommon.technique + ';';
 
         var values = khrMaterialsCommon.values;
         var keys = Object.keys(values).sort();
         var keysCount = keys.length;
         for (var i=0;i<keysCount;++i) {
             var name = keys[i];
-            if (values.hasOwnProperty(name)) {
-                var value = values[name];
-                techniqueKey += name + ':' + value.type.toString();
+            //generate first part of key using shader parameters for KHR_materials_common attributes
+            //(including a check, because some boolean flags should not be used as shader parameters)
+            if (values.hasOwnProperty(name) &&
+                name !== "transparent" && name !== "doubleSided") {
+                techniqueKey += name + ':' + getKHRMaterialsCommonValueType(name, values[name]);
                 techniqueKey += ';';
             }
         }
@@ -692,7 +741,17 @@ define([
                         for (var valueName in values) {
                             if (values.hasOwnProperty(valueName)) {
                                 var value = values[valueName];
-                                material.values[valueName] = value.value;
+
+                                // for compatibility with old glb files, encoding materials using
+                                // KHR_materials_common with explicit "type" / "value" members
+                                if (defined(value.value))
+                                {
+                                    material.values[valueName] = value.value;
+                                }
+                                else
+                                {
+                                    material.values[valueName] = value;
+                                }
                             }
                         }