[CHANGE] - renamed step property to sample as it is a more telling name.

src/modules/directVolumeRendering/WMDirectVolumeRendering.cpp

@@ -99,10 +99,10 @@ void WMDirectVolumeRendering::properties()
     // Initialize the properties
     m_propCondition = boost::shared_ptr< WCondition >( new WCondition() );
 
-    m_stepCount     = m_properties->addProperty( "Step count",       "The number of steps to walk along the ray during raycasting. A low value "
-                                                                      "may cause artifacts whilst a high value slows down rendering.", 256 );
-    m_stepCount->setMin( 1 );
-    m_stepCount->setMax( 5000 );
+    m_samples     = m_properties->addProperty( "Sample count", "The number of samples to walk along the ray during raycasting. A low value "
+                                                                 "may cause artifacts whilst a high value slows down rendering.", 256 );
+    m_samples->setMin( 1 );
+    m_samples->setMax( 5000 );
 
     // illumination model
     m_localIlluminationSelections = boost::shared_ptr< WItemSelection >( new WItemSelection() );
@@ -130,7 +130,7 @@ void WMDirectVolumeRendering::properties()
                                                                                       m_propCondition );
 
     m_opacityCorrectionEnabled = m_improvementGroup->addProperty( "Opacity Correction", "If enabled, opacities are assumed to be relative to the "
-                                                                                        "sample count. If disabled, changing the step count "
+                                                                                        "sample count. If disabled, changing the sample count "
                                                                                         "varies brightness of the image.", true,
                                                                                       m_propCondition );
 
@@ -336,10 +336,10 @@ void WMDirectVolumeRendering::moduleMain()
             // for the texture, also bind the appropriate uniforms
             rootState->addUniform( new osg::Uniform( "tex0", 0 ) );
 
-            osg::ref_ptr< osg::Uniform > steps = new osg::Uniform( "u_steps", m_stepCount->get() );
-            steps->setUpdateCallback( new SafeUniformCallback( this ) );
+            osg::ref_ptr< osg::Uniform > samples = new osg::Uniform( "u_samples", m_samples->get() );
+            samples->setUpdateCallback( new SafeUniformCallback( this ) );
 
-            rootState->addUniform( steps );
+            rootState->addUniform( samples );
 
             WGEColormapping::apply( cube, false );
 
@@ -372,9 +372,9 @@ void WMDirectVolumeRendering::moduleMain()
 void WMDirectVolumeRendering::SafeUniformCallback::operator()( osg::Uniform* uniform, osg::NodeVisitor* /* nv */ )
 {
     // update some uniforms:
-    if ( m_module->m_stepCount->changed() && ( uniform->getName() == "u_steps" ) )
+    if ( m_module->m_samples->changed() && ( uniform->getName() == "u_samples" ) )
     {
-        uniform->set( m_module->m_stepCount->get( true ) );
+        uniform->set( m_module->m_samples->get( true ) );
     }
 }
 

src/modules/directVolumeRendering/WMDirectVolumeRendering.h

@@ -116,9 +116,9 @@ private:
     boost::shared_ptr< WModuleInputData< WDataSetVector > > m_gradients;
 
     /**
-     * The number of steps to walk along the ray.
+     * The number of samples to walk along the ray.
      */
-    WPropInt m_stepCount;
+    WPropInt m_samples;
 
     /**
      * Types of local illumination supported.
@@ -172,7 +172,7 @@ private:
 
     /**
      * If active, the opacity of the classified fragment gets scaled according to sample count to ensure relative opacities even if sampling
-     * number changes (m_stepCount)
+     * number changes (m_samples)
      */
     WPropBool m_opacityCorrectionEnabled;
 

src/modules/directVolumeRendering/shaders/WMDirectVolumeRendering-fragment.glsl

@@ -194,7 +194,7 @@ void main()
     // stochastic jittering can help to void these ugly wood-grain artifacts with larger sampling distances but might
     // introduce some noise artifacts.
     float jitter = 0.5 - texture2D( JITTERTEXTURE_SAMPLER, gl_FragCoord.xy / JITTERTEXTURE_SIZEX ).r;
-    vec3 rayStart = v_rayStart + ( v_ray * v_stepDistance * jitter );
+    vec3 rayStart = v_rayStart + ( v_ray * v_sampleDistance * jitter );
 #else
     vec3 rayStart = v_rayStart;
 #endif
@@ -214,17 +214,17 @@ void main()
 
 #ifdef OPACITYCORRECTION_ENABLED
             // opacity correction
-            src.r = 1.0 - fastpow( 1.0 - src.r, v_relativeSteps );
-            src.g = 1.0 - fastpow( 1.0 - src.g, v_relativeSteps );
-            src.b = 1.0 - fastpow( 1.0 - src.b, v_relativeSteps );
-            src.a = 1.0 - fastpow( 1.0 - src.a, v_relativeSteps );
+            src.r = 1.0 - fastpow( 1.0 - src.r, v_relativeSampleDistance );
+            src.g = 1.0 - fastpow( 1.0 - src.g, v_relativeSampleDistance );
+            src.b = 1.0 - fastpow( 1.0 - src.b, v_relativeSampleDistance );
+            src.a = 1.0 - fastpow( 1.0 - src.a, v_relativeSampleDistance );
 #endif
 
             // apply front-to-back compositing
             dst = ( 1.0 - dst.a ) * src + dst;
 
             // go to next value
-            currentDistance += v_stepDistance;
+            currentDistance += v_sampleDistance;
         }
 
         // early ray-termination

src/modules/directVolumeRendering/shaders/WMDirectVolumeRendering-varyings.glsl

@@ -34,10 +34,10 @@ varying vec3 v_rayStart;
 varying vec3 v_ray;
 
 // The sampling distance
-varying float v_stepDistance;
+varying float v_sampleDistance;
 
-// The steps in relation to a default steps of 256.
-varying float v_relativeSteps;
+// The steps in relation to a default steps of 128.
+varying float v_relativeSampleDistance;
 
 #ifdef LOCALILLUMINATION_PHONG
 // The light source in local coordinates, normalized

src/modules/directVolumeRendering/shaders/WMDirectVolumeRendering-vertex.glsl

@@ -39,8 +39,8 @@
 // texture containing the data
 uniform sampler3D tex0;
 
-// The number of steps to use.
-uniform int u_steps;
+// The number of samples to use.
+uniform int u_samples;
 
 /////////////////////////////////////////////////////////////////////////////
 // Attributes
@@ -72,8 +72,8 @@ void main()
     v_ray = normalize( worldToLocal( camLookAt, camPos ).xyz );
 
     // to have equidistant sampling for each side of the box, use a fixed step size
-    v_stepDistance = 1.0 / float( u_steps );
-    v_relativeSteps = 128.0 /  float( u_steps );
+    v_sampleDistance = 1.0 / float( u_samples );
+    v_relativeSampleDistance = 128.0 /  float( u_samples );
 
 #ifdef LOCALILLUMINATION_PHONG
     // also get the coordinates of the light