Implement planar collider for particles (Fixes #2149)

components/nif/controlled.cpp

@@ -65,8 +65,14 @@ namespace Nif
     {
         Controlled::read(nif);
 
-        // (I think) 4 floats + 4 vectors
+        mBounceFactor = nif->getFloat();
-        nif->skip(4*16);
+        /*unknown*/nif->getFloat();
+
+        for (int i=0;i<10;++i)
+            /*unknown*/nif->getFloat();
+
+        mPlaneNormal = nif->getVector3();
+        mPlaneDistance = nif->getFloat();
     }
 
     void NiParticleRotation::read(NIFStream *nif)

components/nif/controlled.hpp

@@ -103,6 +103,11 @@ class NiPlanarCollider : public Controlled
 {
 public:
     void read(NIFStream *nif);
+
+    float mBounceFactor;
+
+    osg::Vec3f mPlaneNormal;
+    float mPlaneDistance;
 };
 
 class NiParticleRotation : public Controlled

components/nif/controller.cpp

@@ -76,8 +76,8 @@ namespace Nif
         }
 
         nif->getUInt(); /* -1? */
-        extra.read(nif);
+        affectors.read(nif);
-        nif->getUInt(); /* -1? */
+        colliders.read(nif);
         nif->getChar();
     }
 
@@ -85,7 +85,8 @@ namespace Nif
     {
         Controller::post(nif);
         emitter.post(nif);
-        extra.post(nif);
+        affectors.post(nif);
+        colliders.post(nif);
     }
 
     void NiMaterialColorController::read(NIFStream *nif)

components/nif/controller.hpp

@@ -72,7 +72,8 @@ public:
     int activeCount;
     std::vector<Particle> particles;
 
-    ExtraPtr extra;
+    ExtraPtr affectors;
+    ExtraPtr colliders;
 
     void read(NIFStream *nif);
     void post(NIFFile *nif);

components/nifosg/nifloader.cpp

@@ -719,39 +719,44 @@ namespace NifOsg
             }
         }
 
-        void handleParticleAffectors(Nif::ExtraPtr e, osg::Group *attachTo, osgParticle::ParticleSystem* partsys, osgParticle::ParticleProcessor::ReferenceFrame rf)
+        void handleParticlePrograms(Nif::ExtraPtr affectors, Nif::ExtraPtr colliders, osg::Group *attachTo, osgParticle::ParticleSystem* partsys, osgParticle::ParticleProcessor::ReferenceFrame rf)
         {
             osgParticle::ModularProgram* program = new osgParticle::ModularProgram;
             attachTo->addChild(program);
             program->setParticleSystem(partsys);
             program->setReferenceFrame(rf);
-            for (; !e.empty(); e = e->extra)
+            for (; !affectors.empty(); affectors = affectors->extra)
             {
-                if (e->recType == Nif::RC_NiParticleGrowFade)
+                if (affectors->recType == Nif::RC_NiParticleGrowFade)
                 {
-                    const Nif::NiParticleGrowFade *gf = static_cast<const Nif::NiParticleGrowFade*>(e.getPtr());
+                    const Nif::NiParticleGrowFade *gf = static_cast<const Nif::NiParticleGrowFade*>(affectors.getPtr());
-                    GrowFadeAffector* affector = new GrowFadeAffector(gf->growTime, gf->fadeTime);
+                    program->addOperator(new GrowFadeAffector(gf->growTime, gf->fadeTime));
-                    program->addOperator(affector);
                 }
-                else if (e->recType == Nif::RC_NiGravity)
+                else if (affectors->recType == Nif::RC_NiGravity)
                 {
-                    const Nif::NiGravity* gr = static_cast<const Nif::NiGravity*>(e.getPtr());
+                    const Nif::NiGravity* gr = static_cast<const Nif::NiGravity*>(affectors.getPtr());
-                    GravityAffector* affector = new GravityAffector(gr);
+                    program->addOperator(new GravityAffector(gr));
-                    program->addOperator(affector);
                 }
-                else if (e->recType == Nif::RC_NiParticleColorModifier)
+                else if (affectors->recType == Nif::RC_NiParticleColorModifier)
                 {
-                    const Nif::NiParticleColorModifier *cl = static_cast<const Nif::NiParticleColorModifier*>(e.getPtr());
+                    const Nif::NiParticleColorModifier *cl = static_cast<const Nif::NiParticleColorModifier*>(affectors.getPtr());
                     const Nif::NiColorData *clrdata = cl->data.getPtr();
-                    ParticleColorAffector* affector = new ParticleColorAffector(clrdata);
+                    program->addOperator(new ParticleColorAffector(clrdata));
-                    program->addOperator(affector);
                 }
-                else if (e->recType == Nif::RC_NiParticleRotation)
+                else if (affectors->recType == Nif::RC_NiParticleRotation)
                 {
                     // TODO: Implement?
                 }
                 else
-                    std::cerr << "Unhandled particle modifier " << e->recName << std::endl;
+                    std::cerr << "Unhandled particle modifier " << affectors->recName << std::endl;
+            }
+            for (; !colliders.empty(); colliders = colliders->extra)
+            {
+                if (colliders->recType == Nif::RC_NiPlanarCollider)
+                {
+                    const Nif::NiPlanarCollider* planarcollider = static_cast<const Nif::NiPlanarCollider*>(colliders.getPtr());
+                    program->addOperator(new PlanarCollider(planarcollider));
+                }
             }
         }
 
@@ -888,7 +893,9 @@ namespace NifOsg
             emitter->setUpdateCallback(callback);
 
             // affectors must be attached *after* the emitter in the scene graph for correct update order
-            handleParticleAffectors(partctrl->extra, emitterNode, partsys.get(), rf);
+            // attach to same node as the ParticleSystem, we need osgParticle Operators to get the correct
+            // localToWorldMatrix for transforming to particle space
+            handleParticlePrograms(partctrl->affectors, partctrl->colliders, parentNode, partsys.get(), rf);
 
             osg::ref_ptr<osg::Geode> geode (new osg::Geode);
             geode->addDrawable(partsys);

components/nifosg/particle.cpp

@@ -303,4 +303,46 @@ void FindRecIndexVisitor::apply(osg::Node &searchNode)
     traverse(searchNode);
 }
 
+PlanarCollider::PlanarCollider(const Nif::NiPlanarCollider *collider)
+    : mBounceFactor(collider->mBounceFactor)
+    , mPlane(-collider->mPlaneNormal, collider->mPlaneDistance)
+{
+}
+
+PlanarCollider::PlanarCollider()
+    : mBounceFactor(0.f)
+{
+}
+
+PlanarCollider::PlanarCollider(const PlanarCollider &copy, const osg::CopyOp &copyop)
+    : osgParticle::Operator(copy, copyop)
+    , mBounceFactor(copy.mBounceFactor)
+    , mPlane(copy.mPlane)
+    , mPlaneInParticleSpace(copy.mPlaneInParticleSpace)
+{
+}
+
+void PlanarCollider::beginOperate(osgParticle::Program *program)
+{
+    mPlaneInParticleSpace = mPlane;
+    if (program->getReferenceFrame() == osgParticle::ParticleProcessor::ABSOLUTE_RF)
+        mPlaneInParticleSpace.transform(program->getLocalToWorldMatrix());
+}
+
+void PlanarCollider::operate(osgParticle::Particle *particle, double dt)
+{
+    float dotproduct = particle->getVelocity() * mPlaneInParticleSpace.getNormal();
+
+    if (dotproduct > 0)
+    {
+        osg::BoundingSphere bs(particle->getPosition(), 0.f);
+        if (mPlaneInParticleSpace.intersect(bs) == 1)
+        {
+            osg::Vec3 reflectedVelocity = particle->getVelocity() - mPlaneInParticleSpace.getNormal() * (2 * dotproduct);
+            reflectedVelocity *= mBounceFactor;
+            particle->setVelocity(reflectedVelocity);
+        }
+    }
+}
+
 }

components/nifosg/particle.hpp

@@ -17,6 +17,7 @@
 namespace Nif
 {
     class NiGravity;
+    class NiPlanarCollider;
 }
 
 namespace NifOsg
@@ -92,6 +93,24 @@ namespace NifOsg
         float mLifetimeRandom;
     };
 
+    class PlanarCollider : public osgParticle::Operator
+    {
+    public:
+        PlanarCollider(const Nif::NiPlanarCollider* collider);
+        PlanarCollider();
+        PlanarCollider(const PlanarCollider& copy, const osg::CopyOp& copyop);
+
+        META_Object(NifOsg, PlanarCollider)
+
+        virtual void beginOperate(osgParticle::Program* program);
+        virtual void operate(osgParticle::Particle* particle, double dt);
+
+    private:
+        float mBounceFactor;
+        osg::Plane mPlane;
+        osg::Plane mPlaneInParticleSpace;
+    };
+
     class GrowFadeAffector : public osgParticle::Operator
     {
     public: