Enabled blending to all but iso surface shader.

Changed the alpha value of the iso surface colour to 1.0

src/osgVolume/RayTracedTechnique.cpp

@@ -173,8 +173,12 @@ void RayTracedTechnique::init()
         }
 
 
+        bool enableBlending = false;
+
         if (shadingModel==MaximumIntensityProjection)
         {
+            enableBlending = true;
+
             if (tf)
             {
                 osg::Texture1D* texture1D = new osg::Texture1D;
@@ -259,6 +263,8 @@ void RayTracedTechnique::init()
         } 
         else if (shadingModel==Light)
         {
+            enableBlending = true;
+
             if (tf)
             {
                 osg::Texture1D* texture1D = new osg::Texture1D;
@@ -301,6 +307,8 @@ void RayTracedTechnique::init()
         }
         else
         {
+            enableBlending = true;
+
             if (tf)
             {
                 osg::notify(osg::NOTICE)<<"Setting up TF path"<<std::endl;
@@ -362,6 +370,13 @@ void RayTracedTechnique::init()
             stateset->addUniform(new osg::Uniform("AlphaFuncValue",alphaFuncValue));
 
 
+        if (enableBlending)
+        {
+            stateset->setMode(GL_BLEND, osg::StateAttribute::ON);
+            stateset->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
+        }
+
+
         stateset->setMode(GL_CULL_FACE, osg::StateAttribute::ON);
 
         osg::TexGen* texgen = new osg::TexGen;

src/osgVolume/Shaders/volume_iso_frag.cpp

@@ -108,8 +108,9 @@ char volume_iso_frag[] = "uniform sampler3D baseTexture;\n"
                          "                color.y = lightScale;\n"
                          "                color.z = lightScale;\n"
                          "            }\n"
-                         "            \n"
+                         "\n"
-                         "            if (color.w>1.0) color.w = 1.0; \n"
+                         "            color.a = 1.0;\n"
+                         "\n"
                          "            gl_FragColor = color;\n"
                          "            \n"
                          "            return;\n"
@@ -124,4 +125,5 @@ char volume_iso_frag[] = "uniform sampler3D baseTexture;\n"
                          "\n"
                          "    // we didn't find an intersection so just discard fragment\n"
                          "    discard;\n"
-                         "}\n";
+                         "}\n"
+                         "\n";