Improve shadow derived command creation. Split up receive from cast

CesiumGS · Sep 5, 2018 · 6de0c0b · 6de0c0b
1 parent 7c1a5b0
commit 6de0c0b
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Showing 4 changed files with 103 additions and 19 deletions.
diff --git a/Source/Scene/Scene.js b/Source/Scene/Scene.js
@@ -1450,15 +1450,13 @@ define([
         var frameState = scene._frameState;
         var context = scene._context;
         var oit = scene._view.oit;
-        var shadowsEnabled = frameState.shadowState.shadowsEnabled;
-        var shadowMaps = frameState.shadowState.shadowMaps;
         var lightShadowMaps = frameState.shadowState.lightShadowMaps;
         var lightShadowsEnabled = frameState.shadowState.lightShadowsEnabled;
 
         var derivedCommands = command.derivedCommands;
 
-        if (shadowsEnabled && (command.receiveShadows || command.castShadows)) {
-            derivedCommands.shadows = ShadowMap.createDerivedCommands(shadowMaps, lightShadowMaps, command, shadowsDirty, context, derivedCommands.shadows);
+        if (lightShadowsEnabled && command.receiveShadows) {
+            derivedCommands.shadows = ShadowMap.createReceiveDerivedCommand(lightShadowMaps, command, shadowsDirty, context, derivedCommands.shadows);
         }
 
         if (defined(command.pickId)) {
@@ -1513,6 +1511,12 @@ define([
         if (command.dirty) {
             command.dirty = false;
 
+            var shadowMaps = frameState.shadowState.shadowMaps;
+            var shadowsEnabled = frameState.shadowState.shadowsEnabled;
+            if (shadowsEnabled && command.castShadows) {
+                derivedCommands.shadows = ShadowMap.createCastDerivedCommand(shadowMaps, command, shadowsDirty, context, derivedCommands.shadows);
+            }
+
             if (hasLogDepthDerivedCommands || needsLogDepthDerivedCommands) {
                 derivedCommands.logDepth = DerivedCommand.createLogDepthCommand(command, context, derivedCommands.logDepth);
                 updateDerivedCommands(this, derivedCommands.logDepth.command, shadowsDirty);

diff --git a/Source/Scene/ShadowMap.js b/Source/Scene/ShadowMap.js
@@ -1606,6 +1606,93 @@ define([
         return result;
     };
 
+    ShadowMap.createReceiveDerivedCommand = function(lightShadowMaps, command, shadowsDirty, context, result) {
+        if (!defined(result)) {
+            result = {};
+        }
+
+        var lightShadowMapsEnabled = (lightShadowMaps.length > 0);
+        var shaderProgram = command.shaderProgram;
+        var vertexShaderSource = shaderProgram.vertexShaderSource;
+        var fragmentShaderSource = shaderProgram.fragmentShaderSource;
+        var isTerrain = command.pass === Pass.GLOBE;
+
+        var hasTerrainNormal = false;
+        if (isTerrain) {
+            hasTerrainNormal = command.owner.data.pickTerrain.mesh.encoding.hasVertexNormals;
+        }
+
+        if (command.receiveShadows && lightShadowMapsEnabled) {
+            // Only generate a receiveCommand if there is a shadow map originating from a light source.
+            var receiveShader;
+            var receiveUniformMap;
+            if (defined(result.receiveCommand)) {
+                receiveShader = result.receiveCommand.shaderProgram;
+                receiveUniformMap = result.receiveCommand.uniformMap;
+            }
+
+            result.receiveCommand = DrawCommand.shallowClone(command, result.receiveCommand);
+            result.castShadows = false;
+            result.receiveShadows = true;
+
+            // If castShadows changed, recompile the receive shadows shader. The normal shading technique simulates
+            // self-shadowing so it should be turned off if castShadows is false.
+            var castShadowsDirty = result.receiveShaderCastShadows !== command.castShadows;
+            var shaderDirty = result.receiveShaderProgramId !== command.shaderProgram.id;
+
+            if (!defined(receiveShader) || shaderDirty || shadowsDirty || castShadowsDirty) {
+                var keyword = ShadowMapShader.getShadowReceiveShaderKeyword(lightShadowMaps[0], command.castShadows, isTerrain, hasTerrainNormal);
+                receiveShader = context.shaderCache.getDerivedShaderProgram(shaderProgram, keyword);
+                if (!defined(receiveShader)) {
+                    var receiveVS = ShadowMapShader.createShadowReceiveVertexShader(vertexShaderSource, isTerrain, hasTerrainNormal);
+                    var receiveFS = ShadowMapShader.createShadowReceiveFragmentShader(fragmentShaderSource, lightShadowMaps[0], command.castShadows, isTerrain, hasTerrainNormal);
+
+                    receiveShader = context.shaderCache.createDerivedShaderProgram(shaderProgram, keyword, {
+                        vertexShaderSource : receiveVS,
+                        fragmentShaderSource : receiveFS,
+                        attributeLocations : shaderProgram._attributeLocations
+                    });
+                }
+
+                receiveUniformMap = combineUniforms(lightShadowMaps[0], command.uniformMap, isTerrain);
+            }
+
+            result.receiveCommand.shaderProgram = receiveShader;
+            result.receiveCommand.uniformMap = receiveUniformMap;
+            result.receiveShaderProgramId = command.shaderProgram.id;
+            result.receiveShaderCastShadows = command.castShadows;
+        }
+
+        console.log(result);
+        return result;
+    };
+
+    ShadowMap.createCastDerivedCommand = function(shadowMaps, command, shadowsDirty, context, result) {
+        if (!defined(result)) {
+            result = {};
+        }
+
+        if (command.castShadows) {
+            var castCommands = result.castCommands;
+            if (!defined(castCommands)) {
+                castCommands = result.castCommands = [];
+            }
+
+            var oldShaderId = result.castShaderProgramId;
+
+            var shadowMapLength = shadowMaps.length;
+            castCommands.length = shadowMapLength;
+
+            for (var i = 0; i < shadowMapLength; ++i) {
+                castCommands[i] = createCastDerivedCommand(shadowMaps[i], shadowsDirty, command, context, oldShaderId, castCommands[i]);
+            }
+
+            result.castShaderProgramId = command.shaderProgram.id;
+        }
+
+        return result;
+    };
+
     /**
      * @private
      */

diff --git a/Source/Scene/ShadowMapShader.js b/Source/Scene/ShadowMapShader.js
@@ -20,7 +20,7 @@ define([
         var defines = vs.defines.slice(0);
         var sources = vs.sources.slice(0);
 
-        vs.defines.push('SHADOW_MAP');
+        defines.push('SHADOW_MAP');
 
         if (isTerrain) {
             defines.push('GENERATE_POSITION');
@@ -132,7 +132,7 @@ define([
         var defines = vs.defines.slice(0);
         var sources = vs.sources.slice(0);
 
-        vs.defines.push('SHADOW_MAP');
+        defines.push('SHADOW_MAP');
 
         if (isTerrain) {
             if (hasTerrainNormal) {

diff --git a/Specs/Scene/ShadowMapSpec.js b/Specs/Scene/ShadowMapSpec.js
@@ -1071,7 +1071,8 @@ defineSuite([
     });
 
     it('model updates derived commands when the shadow map is dirty', function() {
-        var spy = spyOn(ShadowMap, 'createDerivedCommands').and.callThrough();
+        var spy1 = spyOn(ShadowMap, 'createReceiveDerivedCommand').and.callThrough();
+        var spy2 = spyOn(ShadowMap, 'createCastDerivedCommand').and.callThrough();
 
         box.show = true;
         floor.show = true;
@@ -1117,18 +1118,10 @@ defineSuite([
             scene.render();
         }
 
-        var callCount;
-        if (!scene.logarithmicDepthBuffer) {
-            // Expect derived commands to be updated twice for both the floor and box,
-            // once on the first frame and again when the shadow map is dirty
-            callCount = 4;
-        } else {
-            // Same as without log z, but doubled. The derived cast commands do not write log z, but
-            // the derived receive commands do.
-            callCount = 8;
-        }
-
-        expect(spy.calls.count()).toEqual(callCount);
+        // Expect derived commands to be updated twice for both the floor and box,
+        // once on the first frame and again when the shadow map is dirty
+        expect(spy1.calls.count()).toEqual(4);
+        expect(spy2.calls.count()).toEqual(4);
 
         box.show = false;
         floor.show = false;