Transform world-space particle systems in update callback so that animations are accounted for

components/resource/scenemanager.cpp

@@ -31,12 +31,47 @@
 namespace
 {
 
-    /// @todo Do this in updateCallback so that animations are accounted for.
-    class InitWorldSpaceParticlesVisitor : public osg::NodeVisitor
+    class InitWorldSpaceParticlesCallback : public osg::NodeCallback
+    {
+    public:
+        virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
+        {
+            osgParticle::ParticleSystem* partsys = static_cast<osgParticle::ParticleSystem*>(node);
+
+            // HACK: Ignore the InverseWorldMatrix transform the particle system is attached to
+            if (partsys->getNumParents() && partsys->getParent(0)->getNumParents())
+                transformInitialParticles(partsys, partsys->getParent(0)->getParent(0));
+
+            node->removeUpdateCallback(this);
+        }
+
+        void transformInitialParticles(osgParticle::ParticleSystem* partsys, osg::Node* node)
+        {
+            osg::NodePathList nodepaths = node->getParentalNodePaths();
+            if (nodepaths.empty())
+                return;
+            osg::Matrixf worldMat = osg::computeLocalToWorld(nodepaths[0]);
+            worldMat.orthoNormalize(worldMat); // scale is already applied on the particle node
+            for (int i=0; i<partsys->numParticles(); ++i)
+            {
+                partsys->getParticle(i)->transformPositionVelocity(worldMat);
+            }
+
+            // transform initial bounds to worldspace
+            osg::BoundingSphere sphere(partsys->getInitialBound());
+            SceneUtil::transformBoundingSphere(worldMat, sphere);
+            osg::BoundingBox box;
+            box.expandBy(sphere);
+            partsys->setInitialBound(box);
+        }
+
+    };
+
+    class InitParticlesVisitor : public osg::NodeVisitor
     {
     public:
         /// @param mask The node mask to set on ParticleSystem nodes.
-        InitWorldSpaceParticlesVisitor(unsigned int mask)
+        InitParticlesVisitor(unsigned int mask)
             : osg::NodeVisitor(TRAVERSE_ALL_CHILDREN)
             , mMask(mask)
         {
@@ -56,33 +91,12 @@ namespace
             {
                 if (isWorldSpaceParticleSystem(partsys))
                 {
-                    // HACK: Ignore the InverseWorldMatrix transform the particle system is attached to
-                    if (partsys->getNumParents() && partsys->getParent(0)->getNumParents())
-                        transformInitialParticles(partsys, partsys->getParent(0)->getParent(0));
+                    partsys->addUpdateCallback(new InitWorldSpaceParticlesCallback);
                 }
                 partsys->setNodeMask(mMask);
             }
         }
 
-        void transformInitialParticles(osgParticle::ParticleSystem* partsys, osg::Node* node)
-        {
-            osg::NodePathList nodepaths = node->getParentalNodePaths();
-            if (nodepaths.empty())
-                return;
-            osg::Matrixf worldMat = osg::computeLocalToWorld(nodepaths[0]);
-            worldMat.orthoNormalize(worldMat); // scale is already applied on the particle node
-            for (int i=0; i<partsys->numParticles(); ++i)
-            {
-                partsys->getParticle(i)->transformPositionVelocity(worldMat);
-            }
-
-            // transform initial bounds to worldspace
-            osg::BoundingSphere sphere(partsys->getInitialBound());
-            SceneUtil::transformBoundingSphere(worldMat, sphere);
-            osg::BoundingBox box;
-            box.expandBy(sphere);
-            partsys->setInitialBound(box);
-        }
     private:
         unsigned int mMask;
     };
@@ -489,7 +503,7 @@ namespace Resource
         // we can skip any scene graphs without update callbacks since we know that particle emitters will have an update callback set
         if (node->getNumChildrenRequiringUpdateTraversal() > 0)
         {
-            InitWorldSpaceParticlesVisitor visitor (mParticleSystemMask);
+            InitParticlesVisitor visitor (mParticleSystemMask);
             node->accept(visitor);
         }
     }