Introduced SampleRatioValueProperty for more intuitive control of how many samples to take when volume rendering

examples/osgvolume/osgvolume.cpp

@@ -1067,8 +1067,14 @@ int main( int argc, char **argv )
         sp->setActiveProperty(0);
 
         osgVolume::AlphaFuncProperty* ap = new osgVolume::AlphaFuncProperty(alphaFunc);
-        osgVolume::SampleDensityProperty* sd = new osgVolume::SampleDensityProperty(0.005);
+
+        // SampleDensity is now deprecated
+        osgVolume::SampleDensityProperty* sd = new osgVolume::SampleDensityProperty(0.005f);
         osgVolume::SampleDensityWhenMovingProperty* sdwm = sampleDensityWhenMoving!=0.0 ? new osgVolume::SampleDensityWhenMovingProperty(sampleDensityWhenMoving) : 0;
+
+        // use SampleRatio in place of SampleDensity
+        osgVolume::SampleRatioProperty* sr = new osgVolume::SampleRatioProperty(1.0f);
+
         osgVolume::TransparencyProperty* tp = new osgVolume::TransparencyProperty(1.0);
         osgVolume::TransferFunctionProperty* tfp = transferFunction.valid() ? new osgVolume::TransferFunctionProperty(transferFunction.get()) : 0;
 
@@ -1076,8 +1082,10 @@ int main( int argc, char **argv )
             // Standard
             osgVolume::CompositeProperty* cp = new osgVolume::CompositeProperty;
             cp->addProperty(ap);
-            cp->addProperty(sd);
+            if (useMultipass) cp->addProperty(sr);
+            else cp->addProperty(sd);
             cp->addProperty(tp);
+
             if (sdwm) cp->addProperty(sdwm);
             if (tfp) cp->addProperty(tfp);
 
@@ -1088,7 +1096,8 @@ int main( int argc, char **argv )
             // Light
             osgVolume::CompositeProperty* cp = new osgVolume::CompositeProperty;
             cp->addProperty(ap);
-            cp->addProperty(sd);
+            if (useMultipass) cp->addProperty(sr);
+            else cp->addProperty(sd);
             cp->addProperty(tp);
             cp->addProperty(new osgVolume::LightingProperty);
             if (sdwm) cp->addProperty(sdwm);
@@ -1100,7 +1109,8 @@ int main( int argc, char **argv )
         {
             // Isosurface
             osgVolume::CompositeProperty* cp = new osgVolume::CompositeProperty;
-            cp->addProperty(sd);
+            if (useMultipass) cp->addProperty(sr);
+            else cp->addProperty(sd);
             cp->addProperty(tp);
             cp->addProperty(new osgVolume::IsoSurfaceProperty(alphaFunc));
             if (sdwm) cp->addProperty(sdwm);
@@ -1113,7 +1123,10 @@ int main( int argc, char **argv )
             // MaximumIntensityProjection
             osgVolume::CompositeProperty* cp = new osgVolume::CompositeProperty;
             cp->addProperty(ap);
-            cp->addProperty(sd);
+
+            if (useMultipass) cp->addProperty(sr);
+            else cp->addProperty(sd);
+
             cp->addProperty(tp);
             cp->addProperty(new osgVolume::MaximumIntensityProjectionProperty);
             if (sdwm) cp->addProperty(sdwm);

include/osgVolume/Property

@@ -34,6 +34,7 @@ class IsoSurfaceProperty;
 class MaximumIntensityProjectionProperty;
 class LightingProperty;
 class AlphaFuncProperty;
+class SampleRatioProperty;
 class SampleDensityProperty;
 class SampleDensityWhenMovingProperty;
 class TransparencyProperty;
@@ -55,6 +56,7 @@ class OSGVOLUME_EXPORT PropertyVisitor
         virtual void apply(AlphaFuncProperty&) {}
         virtual void apply(MaximumIntensityProjectionProperty&) {}
         virtual void apply(LightingProperty&) {}
+        virtual void apply(SampleRatioProperty&) {}
         virtual void apply(SampleDensityProperty&) {}
         virtual void apply(SampleDensityWhenMovingProperty&) {}
         virtual void apply(TransparencyProperty&) {}
@@ -327,6 +329,25 @@ class OSGVOLUME_EXPORT SampleDensityWhenMovingProperty : public ScalarProperty
         virtual ~SampleDensityWhenMovingProperty() {}
 };
 
+/** Sample density to use when the volume is static relative to the eye point or when moving if no SampleDensityWhenMovingProperty is assigned.*/
+class OSGVOLUME_EXPORT SampleRatioProperty : public ScalarProperty
+{
+    public:
+
+        SampleRatioProperty(float value=1.0f);
+
+        SampleRatioProperty(const SampleRatioProperty& isp,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
+
+        META_Object(osgVolume, SampleRatioProperty);
+
+        virtual void accept(PropertyVisitor& pv) { pv.apply(*this); }
+
+    protected:
+
+        virtual ~SampleRatioProperty() {}
+};
+
+
 class OSGVOLUME_EXPORT TransparencyProperty : public ScalarProperty
 {
     public:
@@ -360,6 +381,7 @@ class OSGVOLUME_EXPORT CollectPropertiesVisitor : public osgVolume::PropertyVisi
         virtual void apply(LightingProperty& lp);
         virtual void apply(SampleDensityProperty& sdp);
         virtual void apply(SampleDensityWhenMovingProperty& sdp);
+        virtual void apply(SampleRatioProperty& sdp);
         virtual void apply(TransparencyProperty& tp);
 
         osg::ref_ptr<TransferFunctionProperty>              _tfProperty;
@@ -369,6 +391,7 @@ class OSGVOLUME_EXPORT CollectPropertiesVisitor : public osgVolume::PropertyVisi
         osg::ref_ptr<LightingProperty>                      _lightingProperty;
         osg::ref_ptr<SampleDensityProperty>                 _sampleDensityProperty;
         osg::ref_ptr<SampleDensityWhenMovingProperty>       _sampleDensityWhenMovingProperty;
+        osg::ref_ptr<SampleRatioProperty>                   _sampleRatioProperty;
         osg::ref_ptr<TransparencyProperty>                  _transparencyProperty;
 
 };

src/osgVolume/MultipassTechnique.cpp

@@ -185,10 +185,10 @@ void MultipassTechnique::init()
             alphaFuncValue = cpv._isoProperty->getValue();
         }
 
-        if (cpv._sampleDensityProperty.valid())
+        if (cpv._sampleRatioProperty.valid())
-            stateset->addUniform(cpv._sampleDensityProperty->getUniform());
+            stateset->addUniform(cpv._sampleRatioProperty->getUniform());
         else
-            stateset->addUniform(new osg::Uniform("SampleDensityValue",0.0005f));
+            stateset->addUniform(new osg::Uniform("SampleRatioValue",1.0f));
 
 
         if (cpv._transparencyProperty.valid())
@@ -265,6 +265,8 @@ void MultipassTechnique::init()
 
         osg::ref_ptr<osg::Uniform> volumeCellSize = new osg::Uniform("volumeCellSize", osg::Vec3(1.0f/static_cast<float>(image_3d->s()),1.0f/static_cast<float>(image_3d->t()),1.0f/static_cast<float>(image_3d->r())));
         stateset->addUniform(volumeCellSize.get());
+
+        OSG_NOTICE<<"Texture Dimensions "<<image_3d->s()<<", "<<image_3d->t()<<", "<<image_3d->r()<<std::endl;
     }
 
 

src/osgVolume/Property.cpp

@@ -193,6 +193,21 @@ SampleDensityWhenMovingProperty::SampleDensityWhenMovingProperty(const SampleDen
 {
 }
 
+/////////////////////////////////////////////////////////////////////////////
+//
+// SampleRatioProperty
+//
+SampleRatioProperty::SampleRatioProperty(float value):
+    ScalarProperty("SampleRatioValue",value)
+{
+}
+
+SampleRatioProperty::SampleRatioProperty(const SampleRatioProperty& srp,const osg::CopyOp& copyop):
+    ScalarProperty(srp, copyop)
+{
+}
+
+
 
 /////////////////////////////////////////////////////////////////////////////
 //
@@ -262,6 +277,7 @@ void CollectPropertiesVisitor::apply(MaximumIntensityProjectionProperty& mip) {
 void CollectPropertiesVisitor::apply(LightingProperty& lp) { _lightingProperty = &lp; }
 void CollectPropertiesVisitor::apply(SampleDensityProperty& sdp) { _sampleDensityProperty = &sdp; }
 void CollectPropertiesVisitor::apply(SampleDensityWhenMovingProperty& sdp) { _sampleDensityWhenMovingProperty = &sdp; }
+void CollectPropertiesVisitor::apply(SampleRatioProperty& srp) { _sampleRatioProperty = &srp; }
 void CollectPropertiesVisitor::apply(TransparencyProperty& tp) { _transparencyProperty = &tp; }
 
 
@@ -400,25 +416,25 @@ bool PropertyAdjustmentCallback::handle(const osgGA::GUIEventAdapter& ea,osgGA::
 
         if (_updateAlphaCutOff && cpv._isoProperty.valid())
         {
-            OSG_INFO<<"Setting isoProperty to "<<v<<std::endl;
+            OSG_NOTICE<<"Setting isoProperty to "<<v<<std::endl;
             cpv._isoProperty->setValue(v);
         }
 
         if (_updateAlphaCutOff && cpv._afProperty.valid())
         {
-            OSG_INFO<<"Setting afProperty to "<<v2<<std::endl;
+            OSG_NOTICE<<"Setting afProperty to "<<v2<<std::endl;
             cpv._afProperty->setValue(v2);
         }
 
         if (_updateTransparency && cpv._transparencyProperty.valid())
         {
-            OSG_INFO<<"Setting transparency to "<<v2<<std::endl;
+            OSG_NOTICE<<"Setting transparency to "<<v2<<std::endl;
             cpv._transparencyProperty->setValue(1.0f-v2);
         }
 
         if (_updateSampleDensity && cpv._sampleDensityProperty.valid())
         {
-            OSG_INFO<<"Setting sample density to "<<v4<<std::endl;
+            OSG_NOTICE<<"Setting sample density to "<<v4<<std::endl;
             cpv._sampleDensityProperty->setValue(v4);
         }
         if (_updateSampleDensity && cpv._sampleDensityWhenMovingProperty.valid())
@@ -426,6 +442,13 @@ bool PropertyAdjustmentCallback::handle(const osgGA::GUIEventAdapter& ea,osgGA::
             OSG_INFO<<"Setting sample density when moving to "<<v4<<std::endl;
             cpv._sampleDensityWhenMovingProperty->setValue(v4);
         }
+
+        if (_updateSampleDensity && cpv._sampleRatioProperty.valid())
+        {
+            float sampleRatio = v2*4;
+            OSG_NOTICE<<"Setting sample ratio to "<<sampleRatio<<std::endl;
+            cpv._sampleRatioProperty->setValue(sampleRatio);
+        }
     }