Merge pull request #6584 from likangning93/clippingPlanesIeBugfix

workaround for IE model + clipping planes shader bug
CesiumGS · May 11, 2018 · 97eb855 · 97eb855
2 parents 5acc2cd + 2edcb9d
commit 97eb855
Show file tree

Hide file tree

Showing 2 changed files with 24 additions and 10 deletions.
diff --git a/CHANGES.md b/CHANGES.md
@@ -23,6 +23,7 @@ Change Log
 * Fixed incorrect 3D Tiles statistics when a tile fails during processing. [#6558](https://github.com/AnalyticalGraphicsInc/cesium/pull/6558)
 * Fixed race condition causing intermittent crash when changing geometry show value [#3061](https://github.com/AnalyticalGraphicsInc/cesium/issues/3061)
 * `ProviderViewModel`s with no category are displayed in an untitled group in `BaseLayerPicker` instead of being labeled as `'Other'` [#6574](https://github.com/AnalyticalGraphicsInc/cesium/pull/6574)
+* Added a workaround for clipping planes causing a picking shader compilation failure for gltf models and 3D Tilesets in Internet Explorer [#6575](https://github.com/AnalyticalGraphicsInc/cesium/issues/6575)
 
 ### 1.45 - 2018-05-01
 

diff --git a/Source/Scene/Model.js b/Source/Scene/Model.js
@@ -1995,10 +1995,16 @@ define([
         var drawVS = modifyShader(vs, id, model._vertexShaderLoaded);
         var drawFS = modifyShader(fs, id, model._fragmentShaderLoaded);
 
-        drawVS = ModelUtility.modifyVertexShaderForLogDepth(drawVS, toClipCoordinatesGLSL);
-        drawFS = ModelUtility.modifyFragmentShaderForLogDepth(drawFS);
+        // Internet Explorer seems to have problems with discard (for clipping planes) after too many levels of indirection:
+        // https://github.com/AnalyticalGraphicsInc/cesium/issues/6575.
+        // For IE log depth code is defined out anyway due to unsupported WebGL extensions, so the wrappers can be omitted.
+        if (!FeatureDetection.isInternetExplorer()) {
+            drawVS = ModelUtility.modifyVertexShaderForLogDepth(drawVS, toClipCoordinatesGLSL);
+            drawFS = ModelUtility.modifyFragmentShaderForLogDepth(drawFS);
+        }
 
-        var pickFS, pickVS;
+        var pickFS;
+        var pickVS;
         if (model.allowPicking) {
             // PERFORMANCE_IDEA: Can optimize this shader with a glTF hint. https://github.com/KhronosGroup/glTF/issues/181
             pickVS = modifyShader(vs, id, model._pickVertexShaderLoaded);
@@ -2008,8 +2014,10 @@ define([
                 pickFS = ShaderSource.createPickFragmentShaderSource(fs, 'uniform');
             }
 
-            pickVS = ModelUtility.modifyVertexShaderForLogDepth(pickVS, toClipCoordinatesGLSL);
-            pickFS = ModelUtility.modifyFragmentShaderForLogDepth(pickFS);
+            if (!FeatureDetection.isInternetExplorer()) {
+                pickVS = ModelUtility.modifyVertexShaderForLogDepth(pickVS, toClipCoordinatesGLSL);
+                pickFS = ModelUtility.modifyFragmentShaderForLogDepth(pickFS);
+            }
         }
         createAttributesAndProgram(id, drawFS, drawVS, pickFS, pickVS, model, context);
     }
@@ -2041,10 +2049,13 @@ define([
         var drawVS = modifyShader(vs, id, model._vertexShaderLoaded);
         var drawFS = modifyShader(finalFS, id, model._fragmentShaderLoaded);
 
-        drawVS = ModelUtility.modifyVertexShaderForLogDepth(drawVS, toClipCoordinatesGLSL);
-        drawFS = ModelUtility.modifyFragmentShaderForLogDepth(drawFS);
+        if (!FeatureDetection.isInternetExplorer()) {
+            drawVS = ModelUtility.modifyVertexShaderForLogDepth(drawVS, toClipCoordinatesGLSL);
+            drawFS = ModelUtility.modifyFragmentShaderForLogDepth(drawFS);
+        }
 
-        var pickFS, pickVS;
+        var pickFS;
+        var pickVS;
         if (model.allowPicking) {
             // PERFORMANCE_IDEA: Can optimize this shader with a glTF hint. https://github.com/KhronosGroup/glTF/issues/181
             pickVS = modifyShader(vs, id, model._pickVertexShaderLoaded);
@@ -2058,8 +2069,10 @@ define([
                 pickFS = modifyShaderForClippingPlanes(pickFS, clippingPlaneCollection);
             }
 
-            pickVS = ModelUtility.modifyVertexShaderForLogDepth(pickVS, toClipCoordinatesGLSL);
-            pickFS = ModelUtility.modifyFragmentShaderForLogDepth(pickFS);
+            if (!FeatureDetection.isInternetExplorer()) {
+                pickVS = ModelUtility.modifyVertexShaderForLogDepth(pickVS, toClipCoordinatesGLSL);
+                pickFS = ModelUtility.modifyFragmentShaderForLogDepth(pickFS);
+            }
         }
         createAttributesAndProgram(id, drawFS, drawVS, pickFS, pickVS, model, context);
     }