[CHANGE #298] adapt navslices and marching cubes to the new threshold

behavior. On this way a couple of other things have been fixed:
* use only 8 textures because the compiler told me
    "undefined variable "gl_MultiTexCoord8""
* simplified highlighting of picked slices as they have the correct size for
 some time now
* removed some commented useless code
* fixed the problem that isosurfaces could show only one texture
* simplified calling of renderSurface function in marching cubes module

src/graphicsEngine/shaders/utils.fs

+//
+// This makes threshold lying between min and max to lie between 0 and 1
+// where 0 correspond to min and 1 to max
+//
+float scaleZeroOne( in float threshold, in float min, in float max )
+{
+    return ( threshold - min ) / ( max - min );
+}

src/modules/marchingCubes/WMMarchingCubes.cpp

@@ -144,9 +144,6 @@ void WMMarchingCubes::moduleMain()
 
         generateSurfacePre( m_isoValueProp->get() );
 
-        // TODO(wiebel): MC remove this from here
-        //    renderMesh( load( "/tmp/isosurfaceTestMesh.vtk" ) );
-
         ++*progress;
         debugLog() << "Rendering surface ...";
 
@@ -154,7 +151,9 @@ void WMMarchingCubes::moduleMain()
         m_shaderUseLighting = true;
         m_shaderUseTransparency = true;
 
-        renderSurface();
+        renderMesh();
+        m_output->updateData( m_triMesh );
+
         debugLog() << "Done!";
         progress->finish();
 
@@ -273,13 +272,7 @@ void WMMarchingCubes::generateSurfacePre( double isoValue )
     }
 }
 
-void WMMarchingCubes::renderSurface()
-{
-    renderMesh( m_triMesh );
-    m_output->updateData( m_triMesh );
-}
-
-void WMMarchingCubes::renderMesh( boost::shared_ptr< WTriangleMesh2 > mesh )
+void WMMarchingCubes::renderMesh()
 {
 //    WKernel::getRunningKernel()->getGraphicsEngine()->getScene()
     m_moduleNode->remove( m_surfaceGeode );
@@ -288,13 +281,13 @@ void WMMarchingCubes::renderMesh( boost::shared_ptr< WTriangleMesh2 > mesh )
 
     m_surfaceGeode->setName( "iso surface" );
 
-    surfaceGeometry->setVertexArray( mesh->getVertexArray() );
+    surfaceGeometry->setVertexArray( m_triMesh->getVertexArray() );
 
     osg::DrawElementsUInt* surfaceElement;
 
     surfaceElement = new osg::DrawElementsUInt( osg::PrimitiveSet::TRIANGLES, 0 );
 
-    std::vector< size_t >tris = mesh->getTriangles();
+    std::vector< size_t >tris = m_triMesh->getTriangles();
     surfaceElement->reserve( tris.size() );
 
     for( unsigned int vertId = 0; vertId < tris.size(); ++vertId )
@@ -305,7 +298,7 @@ void WMMarchingCubes::renderMesh( boost::shared_ptr< WTriangleMesh2 > mesh )
 
     // ------------------------------------------------
     // normals
-    surfaceGeometry->setNormalArray( mesh->getVertexNormalArray() );
+    surfaceGeometry->setNormalArray( m_triMesh->getVertexNormalArray() );
     surfaceGeometry->setNormalBinding( osg::Geometry::BIND_PER_VERTEX );
 
     m_surfaceGeode->addDrawable( surfaceGeometry );
@@ -338,14 +331,6 @@ void WMMarchingCubes::renderMesh( boost::shared_ptr< WTriangleMesh2 > mesh )
     // ------------------------------------------------
     // Shader stuff
 
-    osg::Vec3Array* texCoords = new osg::Vec3Array;
-    for( size_t i = 0; i < mesh->vertSize(); ++i )
-    {
-        osg::Vec3 vertPos = mesh->getVertex( i );
-        texCoords->push_back( wge::wv3D2ov3( m_grid->worldCoordToTexCoord( wmath::WPosition( vertPos[0], vertPos[1], vertPos[2] ) ) ) );
-    }
-    surfaceGeometry->setTexCoordArray( 0, texCoords );
-
     m_typeUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "type0", 0 ) ) );
     m_typeUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "type1", 0 ) ) );
     m_typeUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "type2", 0 ) ) );
@@ -379,6 +364,28 @@ void WMMarchingCubes::renderMesh( boost::shared_ptr< WTriangleMesh2 > mesh )
     m_thresholdUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "threshold8", 0.0f ) ) );
     m_thresholdUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "threshold9", 0.0f ) ) );
 
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min0", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min1", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min2", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min3", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min4", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min5", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min6", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min7", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min8", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min9", 0.0f ) ) );
+
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max0", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max1", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max2", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max3", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max4", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max5", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max6", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max7", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max8", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max9", 0.0f ) ) );
+
     m_samplerUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "tex0", 0 ) ) );
     m_samplerUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "tex1", 1 ) ) );
     m_samplerUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "tex2", 2 ) ) );
@@ -405,14 +412,13 @@ void WMMarchingCubes::renderMesh( boost::shared_ptr< WTriangleMesh2 > mesh )
     {
         state->addUniform( m_typeUniforms[i] );
         state->addUniform( m_thresholdUniforms[i] );
+        state->addUniform( m_minUniforms[i] );
+        state->addUniform( m_maxUniforms[i] );
         state->addUniform( m_alphaUniforms[i] );
         state->addUniform( m_samplerUniforms[i] );
         state->addUniform( m_cmapUniforms[i] );
     }
 
-    // TODO(wiebel): used? Not used? Replace by new Property please
-    // state->addUniform( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "useTexture", m_properties->getValue< bool >( "Use Texture" ) ) ) );
-
     state->addUniform( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "useLighting", m_shaderUseLighting ) ) );
     if( m_shaderUseTransparency )
     {
@@ -434,8 +440,6 @@ void WMMarchingCubes::renderMesh( boost::shared_ptr< WTriangleMesh2 > mesh )
     WKernel::getRunningKernel()->getGraphicsEngine()->getScene()->insert( m_moduleNode );
 
     m_moduleNode->addUpdateCallback( new SurfaceNodeCallback( this ) );
-
-    //osgDB::writeNodeFile( *m_surfaceGeode, "/tmp/saved.osg" ); //for debugging
 }
 
 // TODO(wiebel): move this somewhere, where more classes can use it
@@ -555,6 +559,7 @@ void WMMarchingCubes::updateGraphics()
 
     if ( m_textureChanged || m_opacityProp->changed() || m_useTextureProp->changed()  )
     {
+        bool localTextureChangedFlag = m_textureChanged;
         m_textureChanged = false;
 
         // grab a list of data textures
@@ -586,16 +591,35 @@ void WMMarchingCubes::updateGraphics()
             int c = 0;
             for ( std::vector< boost::shared_ptr< WDataTexture3D > >::const_iterator iter = tex.begin(); iter != tex.end(); ++iter )
             {
+                if( localTextureChangedFlag )
+                {
+                    osg::ref_ptr< osg::Geometry > surfaceGeometry = m_surfaceGeode->getDrawable( 0 )->asGeometry();
+                    osg::Vec3Array* texCoords = new osg::Vec3Array;
+                    boost::shared_ptr< WGridRegular3D > grid = ( *iter )->getGrid();
+                    for( size_t i = 0; i < m_triMesh->vertSize(); ++i )
+                    {
+                        osg::Vec3 vertPos = m_triMesh->getVertex( i );
+                        texCoords->push_back( wge::wv3D2ov3( grid->worldCoordToTexCoord( wmath::WPosition( vertPos[0], vertPos[1], vertPos[2] ) ) ) );
+                    }
+                    surfaceGeometry->setTexCoordArray( c, texCoords );
+                }
+
                 osg::ref_ptr<osg::Texture3D> texture3D = ( *iter )->getTexture();
                 rootState->setTextureAttributeAndModes( c, texture3D, osg::StateAttribute::ON );
 
                 // set threshold/opacity as uniforms
-                float t = ( *iter )->getThreshold() / 255.0;
+                float t = ( *iter )->getThreshold();
                 float a = ( *iter )->getAlpha();
                 int cmap = ( *iter )->getSelectedColormap();
 
                 m_typeUniforms[c]->set( ( *iter )->getDataType() );
                 m_thresholdUniforms[c]->set( t );
+                {
+                    float minValue = ( *iter )->getMinValue();
+                    float maxValue = ( *iter )->getMaxValue();
+                    m_minUniforms[c]->set( minValue );
+                    m_maxUniforms[c]->set( maxValue );
+                }
                 m_alphaUniforms[c]->set( a );
                 m_cmapUniforms[c]->set( cmap );
 

src/modules/marchingCubes/WMMarchingCubes.h

@@ -90,12 +90,6 @@ public:
      */
     virtual const char** getXPMIcon() const;
 
-    /**
-     * Activate the rendering of the computed surface.
-     * This converts the surface to a WTriangleMesh2 and calls renderMesh afterwards
-     */
-    void renderSurface();
-
     /**
      *  updates textures and shader parameters
      */
@@ -126,9 +120,8 @@ private:
 
     /**
      * Prepares and commits everything for rendering with the OSG
-     * \param mesh The mesh that will be rendered.
      */
-    void renderMesh( boost::shared_ptr< WTriangleMesh2 > mesh );
+    void renderMesh();
 
     /**
      * Store the mesh in legacy vtk file format.
@@ -195,10 +188,12 @@ private:
     std::vector< osg::ref_ptr< osg::Uniform > > m_typeUniforms; //!< uniforms for ...... ? for shader
     std::vector< osg::ref_ptr< osg::Uniform > > m_alphaUniforms; //!< uniforms for opacities of textures in shader
     std::vector< osg::ref_ptr< osg::Uniform > > m_thresholdUniforms; //!< uniforms for thresholds of textures in shader
+    std::vector< osg::ref_ptr<osg::Uniform> > m_minUniforms; //!< minimum value per texture
+    std::vector< osg::ref_ptr<osg::Uniform> > m_maxUniforms; //!< maximu value per texture
     std::vector< osg::ref_ptr< osg::Uniform > > m_samplerUniforms; //!< uniforms for ids of textures in shader
     std::vector< osg::ref_ptr<osg::Uniform> > m_cmapUniforms; //!< uniforms for color maps per texture in shader
 
-    static const int m_maxNumberOfTextures = 10; //!< We support only 10 textures because hardware has may have unknown limits.
+    static const int m_maxNumberOfTextures = 8; //!< We support only 8 textures because some known hardware does not support more texture coordinates.
 };
 
 /**

src/modules/marchingCubes/shaders/surface.fs

@@ -6,12 +6,6 @@ varying vec4 VaryingTexCoord4;
 varying vec4 VaryingTexCoord5;
 varying vec4 VaryingTexCoord6;
 varying vec4 VaryingTexCoord7;
-varying vec4 VaryingTexCoord8;
-varying vec4 VaryingTexCoord9;
-
-uniform bool useLighting;
-uniform bool useTexture;
-uniform int opacity;
 
 uniform sampler3D tex0;
 uniform sampler3D tex1;
@@ -21,8 +15,6 @@ uniform sampler3D tex4;
 uniform sampler3D tex5;
 uniform sampler3D tex6;
 uniform sampler3D tex7;
-uniform sampler3D tex8;
-uniform sampler3D tex9;
 
 uniform float threshold0;
 uniform float threshold1;
@@ -32,9 +24,24 @@ uniform float threshold4;
 uniform float threshold5;
 uniform float threshold6;
 uniform float threshold7;
-uniform float threshold8;
-uniform float threshold9;
 
+uniform float min0;
+uniform float min1;
+uniform float min2;
+uniform float min3;
+uniform float min4;
+uniform float min5;
+uniform float min6;
+uniform float min7;
+
+uniform float max0;
+uniform float max1;
+uniform float max2;
+uniform float max3;
+uniform float max4;
+uniform float max5;
+uniform float max6;
+uniform float max7;
 
 uniform int type0;
 uniform int type1;
@@ -44,8 +51,6 @@ uniform int type4;
 uniform int type5;
 uniform int type6;
 uniform int type7;
-uniform int type8;
-uniform int type9;
 
 uniform float alpha0;
 uniform float alpha1;
@@ -55,8 +60,6 @@ uniform float alpha4;
 uniform float alpha5;
 uniform float alpha6;
 uniform float alpha7;
-uniform float alpha8;
-uniform float alpha9;
 
 uniform int useCmap0;
 uniform int useCmap1;
@@ -66,14 +69,17 @@ uniform int useCmap4;
 uniform int useCmap5;
 uniform int useCmap6;
 uniform int useCmap7;
-uniform int useCmap8;
-uniform int useCmap9;
+
+uniform bool useLighting;
+uniform bool useTexture;
+uniform int opacity;
 
 
 #include "colorMaps.fs"
+#include "utils.fs"
 #include "lighting.fs"
 
-void lookupTex(inout vec4 col, in int type, in sampler3D tex,  in float threshold, in vec3 v, in float alpha, in int cmap)
+void lookupTex( inout vec4 col, in int type, in sampler3D tex, in float threshold, in vec3 v, in float alpha, in int cmap)
 {
     vec3 col1 = vec3(0.0);
 
@@ -83,12 +89,12 @@ void lookupTex(inout vec4 col, in int type, in sampler3D tex,  in float threshol
 
     if( cmap != 0 )
     {
-        if (threshold < 1.0)
+        if(threshold < 1.0)
         {
             col1.r = (col1.r - threshold) / (1.0 - threshold);
         }
 
-        colorMap(col1, col1.r, cmap );
+        colorMap( col1, col1.r, cmap );
     }
 
     col.rgb = mix( col.rgb, col1.rgb, alpha);
@@ -107,8 +113,15 @@ void main()
 
     if( useTexture )
     {
-        if ( type9 > 0 ) lookupTex(col, type9, tex9, threshold9, VaryingTexCoord9.xyz, alpha9, useCmap9);
-        if ( type8 > 0 ) lookupTex(col, type8, tex8, threshold8, VaryingTexCoord8.xyz, alpha8, useCmap8);
+        threshold0 = scaleZeroOne( threshold0, min0, max0 );
+        threshold1 = scaleZeroOne( threshold1, min1, max1 );
+        threshold2 = scaleZeroOne( threshold2, min2, max2 );
+        threshold3 = scaleZeroOne( threshold3, min3, max3 );
+        threshold4 = scaleZeroOne( threshold4, min4, max4 );
+        threshold5 = scaleZeroOne( threshold5, min5, max5 );
+        threshold6 = scaleZeroOne( threshold6, min6, max6 );
+        threshold7 = scaleZeroOne( threshold7, min7, max7 );
+
         if ( type7 > 0 ) lookupTex(col, type7, tex7, threshold7, VaryingTexCoord7.xyz, alpha7, useCmap7);
         if ( type6 > 0 ) lookupTex(col, type6, tex6, threshold6, VaryingTexCoord6.xyz, alpha6, useCmap6);
         if ( type5 > 0 ) lookupTex(col, type5, tex5, threshold5, VaryingTexCoord5.xyz, alpha5, useCmap5);
@@ -118,6 +131,7 @@ void main()
         if ( type1 > 0 ) lookupTex(col, type1, tex1, threshold1, VaryingTexCoord1.xyz, alpha1, useCmap1);
         if ( type0 > 0 ) lookupTex(col, type0, tex0, threshold0, VaryingTexCoord0.xyz, alpha0, useCmap0);
     }
+
     if ( useLighting )
     {
         col = (ambient * col / 2.0) + (diffuse * col) + (specular * col / 2.0);
@@ -125,11 +139,7 @@ void main()
 
     col = clamp(col, 0.0, 1.0);
 
-
-    //discard completely black voxels. So if no texture is active we will see nothing
-    if ( ( col.r + col.g + col.b ) < 0.01 )
-        discard;
-
+    // opacity of the surface
     col.a = opacity * .01;
 
     gl_FragColor = col;

src/modules/marchingCubes/shaders/surface.vs

 varying vec4 VaryingTexCoord0;
+varying vec4 VaryingTexCoord1;
+varying vec4 VaryingTexCoord2;
+varying vec4 VaryingTexCoord3;
+varying vec4 VaryingTexCoord4;
+varying vec4 VaryingTexCoord5;
+varying vec4 VaryingTexCoord6;
+varying vec4 VaryingTexCoord7;
 
 #include "lighting.vs"
 
 void main()
 {
     VaryingTexCoord0 = gl_MultiTexCoord0;
+    VaryingTexCoord1 = gl_MultiTexCoord1;
+    VaryingTexCoord2 = gl_MultiTexCoord2;
+    VaryingTexCoord3 = gl_MultiTexCoord3;
+    VaryingTexCoord4 = gl_MultiTexCoord4;
+    VaryingTexCoord5 = gl_MultiTexCoord5;
+    VaryingTexCoord6 = gl_MultiTexCoord6;
+    VaryingTexCoord7 = gl_MultiTexCoord7;
 
     prepareLight();
 

src/modules/navSlices/WMNavSlices.cpp

@@ -41,6 +41,7 @@
 #include "../../dataHandler/WDataSet.h"
 #include "../../dataHandler/WDataHandler.h"
 #include "../../dataHandler/WDataSetSingle.h"
+#include "../../dataHandler/WDataSetScalar.h"
 #include "../../dataHandler/WDataTexture3D.h"
 #include "../../dataHandler/WGridRegular3D.h"
 #include "../../dataHandler/WSubject.h"
@@ -823,12 +824,18 @@ void WMNavSlices::updateTextures()
                 rootState->setTextureAttributeAndModes( c, texture3D, osg::StateAttribute::ON );
 
                 // set threshold/opacity as uniforms
-                float t = ( *iter )->getThreshold() / 255.0;
+                float t = ( *iter )->getThreshold();
                 float a = ( *iter )->getAlpha();
                 int cmap = ( *iter )->getSelectedColormap();
 
                 m_typeUniforms[c]->set( ( *iter )->getDataType() );
                 m_thresholdUniforms[c]->set( t );
+                {
+                    float minValue = ( *iter )->getMinValue();
+                    float maxValue = ( *iter )->getMaxValue();
+                    m_minUniforms[c]->set( minValue );
+                    m_maxUniforms[c]->set( maxValue );
+                }
                 m_alphaUniforms[c]->set( a );
                 m_cmapUniforms[c]->set( cmap );
 
@@ -888,6 +895,28 @@ void WMNavSlices::initUniforms( osg::StateSet* rootState )
     m_thresholdUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "threshold8", 0.0f ) ) );
     m_thresholdUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "threshold9", 0.0f ) ) );
 
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min0", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min1", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min2", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min3", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min4", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min5", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min6", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min7", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min8", 0.0f ) ) );
+    m_minUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "min9", 0.0f ) ) );
+
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max0", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max1", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max2", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max3", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max4", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max5", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max6", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max7", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max8", 0.0f ) ) );
+    m_maxUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "max9", 0.0f ) ) );
+
     m_samplerUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "tex0", 0 ) ) );
     m_samplerUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "tex1", 1 ) ) );
     m_samplerUniforms.push_back( osg::ref_ptr<osg::Uniform>( new osg::Uniform( "tex2", 2 ) ) );
@@ -914,6 +943,8 @@ void WMNavSlices::initUniforms( osg::StateSet* rootState )
     {
         rootState->addUniform( m_typeUniforms[i] );
         rootState->addUniform( m_thresholdUniforms[i] );
+        rootState->addUniform( m_minUniforms[i] );
+        rootState->addUniform( m_maxUniforms[i] );
         rootState->addUniform( m_alphaUniforms[i] );
         rootState->addUniform( m_samplerUniforms[i] );
         rootState->addUniform( m_cmapUniforms[i] );

src/modules/navSlices/WMNavSlices.h

@@ -301,6 +301,9 @@ private:
      */
     std::vector< osg::ref_ptr<osg::Uniform> > m_thresholdUniforms;
 
+    std::vector< osg::ref_ptr<osg::Uniform> > m_minUniforms; //!< minimum value per texture
+    std::vector< osg::ref_ptr<osg::Uniform> > m_maxUniforms; //!< maximu value per texture
+
     /**
      * vector of color maps per texture
      */
@@ -320,7 +323,7 @@ private:
      */
     static bool m_navsliceRunning;
 
-    static const int m_maxNumberOfTextures = 10; //!< We support only 10 textures because hardware has may have unknown limits.
+    static const int m_maxNumberOfTextures = 8; //!< We support only 8 textures because some known hardware does not support more texture coordinates.
 
     /**
      * Node callback to handle updates properly

src/modules/navSlices/shaders/slice.fs

@@ -15,8 +15,6 @@ uniform sampler3D tex4;
 uniform sampler3D tex5;
 uniform sampler3D tex6;
 uniform sampler3D tex7;
-uniform sampler3D tex8;
-uniform sampler3D tex9;
 
 uniform float threshold0;
 uniform float threshold1;
@@ -26,8 +24,24 @@ uniform float threshold4;
 uniform float threshold5;
 uniform float threshold6;
 uniform float threshold7;
-uniform float threshold8;
-uniform float threshold9;
+
+uniform float min0;
+uniform float min1;
+uniform float min2;
+uniform float min3;
+uniform float min4;
+uniform float min5;
+uniform float min6;
+uniform float min7;
+
+uniform float max0;
+uniform float max1;
+uniform float max2;
+uniform float max3;
+uniform float max4;
+uniform float max5;
+uniform float max6;
+uniform float max7;
 
 uniform int type0;
 uniform int type1;
@@ -37,8 +51,6 @@ uniform int type4;
 uniform int type5;
 uniform int type6;
 uniform int type7;
-uniform int type8;
-uniform int type9;
 
 uniform float alpha0;
 uniform float alpha1;
@@ -48,8 +60,6 @@ uniform float alpha4;
 uniform float alpha5;
 uniform float alpha6;
 uniform float alpha7;
-uniform float alpha8;
-uniform float alpha9;
 
 uniform int useCmap0;
 uniform int useCmap1;
@@ -59,30 +69,31 @@ uniform int useCmap4;
 uniform int useCmap5;
 uniform int useCmap6;
 uniform int useCmap7;
-uniform int useCmap8;
-uniform int useCmap9;
 
 
 uniform bool highlighted;
 
 
 #include "colorMaps.fs"
+#include "utils.fs"
 
 
-void lookupTex(inout vec4 col, in int type, in sampler3D tex, in float threshold, in vec3 v, in float alpha, in int cmap)
+void lookupTex( inout vec4 col, in int type, in sampler3D tex, in float threshold, in vec3 v, in float alpha, in int cmap)
 {
     vec3 col1 = vec3(0.0);
 
     col1 = clamp( texture3D(tex, v).rgb, 0.0, 1.0);
 
-    if ( ( col1.r + col1.g + col1.b ) / 3.0  - threshold <= 0.0) return;
+    if( ( col1.r + col1.g + col1.b ) / 3.0  - threshold <= 0.0) return;
 
-    if ( cmap != 0 )
+    if( cmap != 0 )
     {
-        if (threshold < 1.0)
+        if(threshold < 1.0)
+        {
             col1.r = (col1.r - threshold) / (1.0 - threshold);
+        }
 
-        colorMap(col1, col1.r, cmap);
+        colorMap( col1, col1.r, cmap );
     }
 
     col.rgb = mix( col.rgb, col1.rgb, alpha);
@@ -92,8 +103,16 @@ void main()
 {
     vec4 col = vec4(0.0, 0.0, 0.0, 1.0);
 
-    if ( type9 > 0 ) lookupTex(col, type9, tex9, threshold9, VaryingTexCoord7.xyz, alpha9, useCmap9);
-    if ( type8 > 0 ) lookupTex(col, type8, tex8, threshold8, VaryingTexCoord7.xyz, alpha8, useCmap8);
+
+    threshold0 = scaleZeroOne( threshold0, min0, max0 );
+    threshold1 = scaleZeroOne( threshold1, min1, max1 );
+    threshold2 = scaleZeroOne( threshold2, min2, max2 );
+    threshold3 = scaleZeroOne( threshold3, min3, max3 );
+    threshold4 = scaleZeroOne( threshold4, min4, max4 );
+    threshold5 = scaleZeroOne( threshold5, min5, max5 );
+    threshold6 = scaleZeroOne( threshold6, min6, max6 );
+    threshold7 = scaleZeroOne( threshold7, min7, max7 );
+
     if ( type7 > 0 ) lookupTex(col, type7, tex7, threshold7, VaryingTexCoord7.xyz, alpha7, useCmap7);
     if ( type6 > 0 ) lookupTex(col, type6, tex6, threshold6, VaryingTexCoord6.xyz, alpha6, useCmap6);
     if ( type5 > 0 ) lookupTex(col, type5, tex5, threshold5, VaryingTexCoord5.xyz, alpha5, useCmap5);
@@ -105,34 +124,16 @@ void main()
 
     col = clamp(col, 0.0, 1.0);
 
-//     col.a = sqrt( col.r * col.r + col.g * col.g + col.b * col.b);
-
     if ( ( col.r + col.g + col.b ) < 0.01 )
     {
-        float upperOuter = 10;
-        float upperInner = 1;
-        float lowerInner = .0;
         if( highlighted )
         {
-            //colorize the slice and mark the border of the first texture
-            if ( ( VaryingTexCoord0.x > upperInner && VaryingTexCoord0.x < upperOuter && VaryingTexCoord0.y < upperOuter  && VaryingTexCoord0.z < upperOuter )
-                              || (VaryingTexCoord0.y > upperInner && VaryingTexCoord0.x < upperOuter && VaryingTexCoord0.y < upperOuter  && VaryingTexCoord0.z < upperOuter )
-                              || (VaryingTexCoord0.z > upperInner && VaryingTexCoord0.x < upperOuter && VaryingTexCoord0.y < upperOuter  && VaryingTexCoord0.z < upperOuter )
-                              || (VaryingTexCoord0.x < lowerInner && VaryingTexCoord0.x < upperOuter && VaryingTexCoord0.y < upperOuter  && VaryingTexCoord0.z < upperOuter )
-                              || (VaryingTexCoord0.y < lowerInner && VaryingTexCoord0.x < upperOuter && VaryingTexCoord0.y < upperOuter  && VaryingTexCoord0.z < upperOuter )
-                              || (VaryingTexCoord0.z < lowerInner && VaryingTexCoord0.x < upperOuter && VaryingTexCoord0.y < upperOuter  && VaryingTexCoord0.z < upperOuter )
-                                  )
-                {
-                    col = vec4(.75, .75, 1, 1);
-                }
-                else
-                {
-                    col = vec4(.7, .7, 1, 1);
-                }
-                }
+            // higlight picked slice in the areas where ther are zero (very small) values
+            col = vec4(.7, .7, 1, 1);
+        }
         else
         {
-             discard;