Merge branch 'ipsvi-raycaster' into 'master'

Ipsvi raycaster



See merge request !5

core/glsl/tools/gradient.frag

@@ -46,7 +46,11 @@ vec3 computeGradientForwardDifferencesLod(in sampler3D tex, in TextureParameters
  * \param   texCoords   Lookup position in texture coordinates
  */
 vec3 computeGradientForwardDifferences(in sampler3D tex, in TextureParameters3D texParams, in vec3 texCoords) {
-    return computeGradientForwardDifferencesLod(tex, texParams, texCoords, 0.0);
+    float v = texture(tex, texCoords).r;
+    float dx = textureOffset(tex, texCoords, ivec3(1, 0, 0)).r;
+    float dy = textureOffset(tex, texCoords, ivec3(0, 1, 0)).r;
+    float dz = textureOffset(tex, texCoords, ivec3(0, 0, 1)).r;
+    return vec3(dx - v, dy - v, dz - v) * texParams._voxelSize;
 }
 
 /**
@@ -73,7 +77,13 @@ vec3 computeGradientCentralDifferencesLod(in sampler3D tex, in TextureParameters
  * \param   texCoords   Lookup position in texture coordinates
  */
 vec3 computeGradientCentralDifferences(in sampler3D tex, in TextureParameters3D texParams, in vec3 texCoords) {
-    return computeGradientCentralDifferencesLod(tex, texParams, texCoords, 0.0);
+    float dx = textureOffset(tex, texCoords, ivec3(1, 0, 0)).r;
+    float dy = textureOffset(tex, texCoords, ivec3(0, 1, 0)).r;
+    float dz = textureOffset(tex, texCoords, ivec3(0, 0, 1)).r;
+    float mdx = textureOffset(tex, texCoords, ivec3(-1, 0, 0)).r;
+    float mdy = textureOffset(tex, texCoords, ivec3(0, -1, 0)).r;
+    float mdz = textureOffset(tex, texCoords, ivec3(0, 0, -1)).r;
+    return vec3(dx - mdx, dy - mdy, dz - mdz) * texParams._voxelSize * 0.5;
 }
 
 

core/glsl/tools/shading.frag

@@ -115,7 +115,7 @@ vec3 calculatePhongShading(in vec3 position, in LightSource light, in vec3 camer
  * \param   normal          Normal
  * \param   materialColor   Material color (used for all shading coefficients)
  */
-vec3 calculatePhongShading(in vec3 position, in LightSource light, in vec3 camera, in vec3 normal, in vec3 materialColor) {
+vec3 calculatePhongShading(in vec3 position, in vec3 ambientColorOverride, LightSource light, in vec3 camera, in vec3 normal, in vec3 materialColor) {
     vec3 N = normalize(normal);
     vec3 V = normalize(camera - position);
 
@@ -124,7 +124,7 @@ vec3 calculatePhongShading(in vec3 position, in LightSource light, in vec3 camer
     float d = length(L);
     L /= d;
 
-    vec3 toReturn = materialColor * light._ambientColor;   // ambient term
+    vec3 toReturn = materialColor * ambientColorOverride;   // ambient term
     toReturn += materialColor * getDiffuseTerm(light._diffuseColor, N, L);
     toReturn += materialColor * getSpecularTerm(light._specularColor, N, L, V, light._shininess);
     #ifdef PHONG_APPLY_ATTENUATION
@@ -133,6 +133,19 @@ vec3 calculatePhongShading(in vec3 position, in LightSource light, in vec3 camer
     return toReturn;
 }
 
+/**
+ * Computes the phong shading according to the given parameters.
+ * 
+ * \param   position        sample position
+ * \param   light           LightSource
+ * \param   camera          Camera position
+ * \param   normal          Normal
+ * \param   materialColor   Material color (used for all shading coefficients)
+ */
+vec3 calculatePhongShading(in vec3 position, in LightSource light, in vec3 camera, in vec3 normal, in vec3 materialColor) {
+    return calculatePhongShading(position, light._ambientColor, light, camera, normal, materialColor);
+}
+
 
 /**
  * Computes the phong shading intensity according to the given parameters.

core/glsl/tools/texture3d.frag

@@ -61,7 +61,7 @@ vec4 textureToWorld(in TextureParameters3D texParams, in vec4 texCoords) {
  */
 vec3 textureToWorld(in TextureParameters3D texParams, in vec3 texCoords) {
     vec4 v = textureToWorld(texParams, vec4(texCoords, 1.0));
-    return v.xyz;
+    return (v / v.w).xyz;
 }
 
 /**
@@ -82,6 +82,7 @@ vec4 worldToTexture(in TextureParameters3D texParams, in vec4 worldCoords) {
  * \param   worldCoords world coordinates
  * \return  \a texCoords transformes to texture coordinates.
  */
-vec4 worldToTexture(in TextureParameters3D texParams, in vec3 worldCoords) {
-    return worldToTexture(texParams, vec4(worldCoords, 1.0));
+vec3 worldToTexture(in TextureParameters3D texParams, in vec3 worldCoords) {
+    vec4 v = worldToTexture(texParams, vec4(worldCoords, 1.0));
+    return (v / v.w).xyz;
 }

core/pipeline/processordecoratorgradient.cpp

@@ -38,10 +38,8 @@ namespace campvis {
     ProcessorDecoratorGradient::ProcessorDecoratorGradient()
         : AbstractProcessorDecorator()
         , p_gradientMethod("GradientMethod", "Gradient Computation Method", gradientOptions, 4)
-        , p_lod("GradientLod", "LOD for Gradient Computation", 0.5f, 0.f, 5.f, .1f, 1)
     {
         p_gradientMethod.setValue(1);
-        p_gradientMethod.s_changed.connect(this, &ProcessorDecoratorGradient::onGradientMethodChanged);
     }
 
     ProcessorDecoratorGradient::~ProcessorDecoratorGradient() {
@@ -50,19 +48,16 @@ namespace campvis {
 
     void ProcessorDecoratorGradient::addProperties(AbstractProcessor* propCollection) {
         propCollection->addProperty(p_gradientMethod, AbstractProcessor::INVALID_SHADER | AbstractProcessor::INVALID_RESULT);
-        propCollection->addProperty(p_lod);
     }
 
     std::string ProcessorDecoratorGradient::generateHeader() const {
         std::string toReturn;
         switch (p_gradientMethod.getOptionValue()) {
             case ForwardDifferences:
-                toReturn.append("#define computeGradient(tex, texParams, texCoords) computeGradientForwardDifferencesLod(tex, texParams, texCoords, _gradientLod)\n");
-                toReturn.append("uniform float _gradientLod = 0.0;\n");
+                toReturn.append("#define computeGradient(tex, texParams, texCoords) computeGradientForwardDifferences(tex, texParams, texCoords)\n");
                 break;
             case CentralDifferences:
-                toReturn.append("#define computeGradient(tex, texParams, texCoords) computeGradientCentralDifferencesLod(tex, texParams, texCoords, _gradientLod)\n");
-                toReturn.append("uniform float _gradientLod = 0.0;\n");
+                toReturn.append("#define computeGradient(tex, texParams, texCoords) computeGradientCentralDifferences(tex, texParams, texCoords)\n");
                 break;
             case FilteredCentralDifferences:
                 toReturn.append("#define computeGradient(tex, texParams, texCoords) computeGradientFilteredCentralDifferences(tex, texParams, texCoords)\n");
@@ -78,14 +73,4 @@ namespace campvis {
         return toReturn;
     }
 
-    void ProcessorDecoratorGradient::renderProlog(const DataContainer& dataContainer, cgt::Shader* shader) {
-        if (p_gradientMethod.getOptionValue() == ForwardDifferences || p_gradientMethod.getOptionValue() == CentralDifferences) {
-            shader->setUniform("_gradientLod", p_lod.getValue());
-        }
-    }
-
-    void ProcessorDecoratorGradient::onGradientMethodChanged(const AbstractProperty* prop) {
-        p_lod.setVisible(p_gradientMethod.getOptionValue() == ForwardDifferences || p_gradientMethod.getOptionValue() == CentralDifferences);
-    }
-
 }

core/pipeline/processordecoratorgradient.h

@@ -59,16 +59,10 @@ namespace campvis {
     protected:
         /// \see AbstractProcessorDecorator::addProperties()
         void addProperties(AbstractProcessor* propCollection);
-        /// \see AbstractProcessorDecorator::renderProlog()
-        virtual void renderProlog(const DataContainer& dataContainer, cgt::Shader* shader);
         /// \see AbstractProcessorDecorator::generateHeader()
         std::string generateHeader() const;
 
-        /// Callback method when p_gradientMethod has changed
-        void onGradientMethodChanged(const AbstractProperty* prop);
-
         GenericOptionProperty<GradientMethod> p_gradientMethod;  ///< Method for calculating the gradients
-        FloatProperty p_lod;        ///< LOD to use for texture lookup during gradient computation
 
     };
 

core/pipeline/raycastingprocessor.cpp

@@ -95,17 +95,6 @@ namespace campvis {
 
         if (img != nullptr && entryPoints != nullptr && exitPoints != nullptr && camera != nullptr) {
             if (img->getDimensionality() == 3) {
-                // little hack to support LOD texture lookup for the gradients:
-                // if texture does not yet have mipmaps, create them.
-                const cgt::Texture* tex = img->getTexture();
-                if (tex->getFilter() != cgt::Texture::MIPMAP) {
-                    const_cast<cgt::Texture*>(tex)->setFilter(cgt::Texture::MIPMAP);
-                    glGenerateMipmap(GL_TEXTURE_3D);
-                    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-                    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
-                    LGL_ERROR;
-                }
-
                 _shader->activate();
                 _shader->setIgnoreUniformLocationError(true);
 

ext/cgt/gpucapabilities.cpp

@@ -472,6 +472,9 @@ const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::CGT_GL_VERSION_3_3(
 const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::CGT_GL_VERSION_4_0(4,0,0);
 const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::CGT_GL_VERSION_4_1(4,1,0);
 const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::CGT_GL_VERSION_4_2(4,2,0);
+const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::CGT_GL_VERSION_4_3(4,3,0);
+const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::CGT_GL_VERSION_4_4(4,4,0);
+const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::CGT_GL_VERSION_4_5(4,5,0);
 
 const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::SHADER_VERSION_110(1,10); ///< GLSL version 1.10
 const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::SHADER_VERSION_120(1,20); ///< GLSL version 1.20
@@ -482,6 +485,9 @@ const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::SHADER_VERSION_330(
 const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::SHADER_VERSION_400(4, 0); ///< GLSL version 4.00
 const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::SHADER_VERSION_410(4,10); ///< GLSL version 4.10
 const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::SHADER_VERSION_420(4,20); ///< GLSL version 4.20
+const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::SHADER_VERSION_430(4,30); ///< GLSL version 4.30
+const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::SHADER_VERSION_440(4,40); ///< GLSL version 4.40
+const GpuCapabilities::GlVersion GpuCapabilities::GlVersion::SHADER_VERSION_450(4,50); ///< GLSL version 4.50
 
 GpuCapabilities::GlVersion::GlVersion(int major, int minor, int release)
   : major_(major), minor_(minor), release_(release)

ext/cgt/gpucapabilities.h

@@ -114,6 +114,9 @@ public:
         static const GlVersion CGT_GL_VERSION_4_0;
         static const GlVersion CGT_GL_VERSION_4_1;
         static const GlVersion CGT_GL_VERSION_4_2;
+        static const GlVersion CGT_GL_VERSION_4_3;
+        static const GlVersion CGT_GL_VERSION_4_4;
+        static const GlVersion CGT_GL_VERSION_4_5;
 
         static const GlVersion SHADER_VERSION_110; ///< GLSL version 1.10
         static const GlVersion SHADER_VERSION_120; ///< GLSL version 1.20
@@ -124,6 +127,9 @@ public:
         static const GlVersion SHADER_VERSION_400; ///< GLSL version 4.00
         static const GlVersion SHADER_VERSION_410; ///< GLSL version 4.10
         static const GlVersion SHADER_VERSION_420; ///< GLSL version 4.20
+        static const GlVersion SHADER_VERSION_430; ///< GLSL version 4.30
+        static const GlVersion SHADER_VERSION_440; ///< GLSL version 4.40
+        static const GlVersion SHADER_VERSION_450; ///< GLSL version 4.50
     };
 
 

modules/vis/glsl/advoptimizedraycaster.frag

@@ -73,6 +73,7 @@ const float SAMPLING_BASE_INTERVAL_RCP = 200.0;
 vec4 performRaycasting(in vec3 entryPoint, in vec3 exitPoint, in vec2 texCoords) {
     vec4 result = vec4(0.0);
     vec3 direction = exitPoint - entryPoint;
+    float len = length(direction);
     
     // Adjust direction a bit to prevent division by zero
     direction.x = (abs(direction.x) < 0.0000001) ? 0.0000001 : direction.x;
@@ -129,7 +130,7 @@ vec4 performRaycasting(in vec3 entryPoint, in vec3 exitPoint, in vec2 texCoords)
         }
 
         // advance to the next evaluation point along the ray
-        tNear += _samplingStepSize;
+        tNear += _samplingStepSize / len;
     }
 
          

modules/vis/glsl/ipsviraycaster.frag

+// ================================================================================================
+// 
+// This file is part of the CAMPVis Software Framework.
+// 
+// If not explicitly stated otherwise: Copyright (C) 2012-2015, all rights reserved,
+//      Christian Schulte zu Berge <christian.szb@in.tum.de>
+//      Chair for Computer Aided Medical Procedures
+//      Technische Universitaet Muenchen
+//      Boltzmannstr. 3, 85748 Garching b. Muenchen, Germany
+// 
+// For a full list of authors and contributors, please refer to the file "AUTHORS.txt".
+// 
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file 
+// except in compliance with the License. You may obtain a copy of the License at
+// 
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software distributed under the 
+// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
+// either express or implied. See the License for the specific language governing permissions 
+// and limitations under the License.
+// 
+// ================================================================================================
+
+layout(location = 0) out vec4 out_Color;     ///< outgoing fragment color
+layout(location = 1) out vec4 out_FHP;       ///< outgoing fragment first hitpoint
+layout(location = 2) out vec4 out_FHN;       ///< outgoing fragment first hit normal
+
+#include "tools/gradient.frag"
+#include "tools/raycasting.frag"
+#include "tools/shading.frag"
+#include "tools/texture2d.frag"
+#include "tools/texture3d.frag"
+#include "tools/transferfunction.frag"
+
+#include "modules/vis/glsl/voxelhierarchy.frag"
+
+uniform vec2 _viewportSizeRCP;
+uniform float _jitterStepSizeMultiplier;
+
+
+// ray entry points
+uniform sampler2D _entryPoints;
+uniform sampler2D _entryPointsDepth;
+uniform TextureParameters2D _entryParams;
+
+// ray exit points
+uniform sampler2D _exitPoints;
+uniform sampler2D _exitPointsDepth;
+uniform TextureParameters2D _exitParams;
+
+// DRR volume
+uniform sampler3D _volume;
+uniform TextureParameters3D _volumeTextureParams;
+
+// Transfer function
+uniform sampler1D _transferFunction;
+uniform TFParameters1D _transferFunctionParams;
+
+
+// Illumination cache
+uniform layout(r32f) image2D _icImageIn;
+uniform layout(r32f) image2D _icImageOut;
+uniform vec3 _icOrigin;
+uniform vec3 _icNormal;
+uniform vec3 _icRightVector;
+uniform vec3 _icUpVector;
+uniform float _shadowIntensity = 0.5;
+
+// Voxel Hierarchy Lookup volume
+uniform usampler2D _voxelHierarchy;
+uniform int _vhMaxMipMapLevel;
+
+
+uniform LightSource _lightSource;
+uniform vec3 _cameraPosition;
+
+uniform float _samplingStepSize;
+const float SAMPLING_BASE_INTERVAL_RCP = 200.0;
+
+// projects a vector in world coordinates onto the IC
+// returns world coordinates
+ivec2 calcIcSamplePosition(vec3 worldPosition) {
+    // project world position onto IC plane
+    const vec3 diag = worldPosition - _icOrigin;
+    const float distance = abs(dot(diag, _icNormal));
+    const vec3 worldProjected = diag - (-distance * _icNormal);
+
+    // transforms world coordinates (have to be lying on the IC plane) to IC pixel space
+    return ivec2(round(dot(worldProjected, _icRightVector)), round(dot(worldProjected, _icUpVector)));
+}
+
+// the composite function can be used for additional shadow ray integration
+// from the current sample to the position of the IC.
+// However, it's currently not used for performance reasons
+void composite(vec3 startPosition, vec3 endPosition, inout float opacity) {
+    vec3 direction = endPosition - startPosition;
+    float t = _samplingStepSize;
+    jitterFloat(t, _samplingStepSize); // jitter startpoint to avoid ringing artifacts (not really effective...)
+
+    float tend = min(length(direction), 4*_samplingStepSize);
+    direction = normalize(direction);
+
+    while (t < tend) {
+        // lookup intensity and TF
+        vec3 samplePosition = startPosition.xyz + t * direction;
+        float intensity = texture(_volume, samplePosition).r;
+        float tfOpacity = lookupTF(_transferFunction, _transferFunctionParams, intensity).a;
+        opacity = opacity + (1.0 - opacity) * tfOpacity;
+
+        t += _samplingStepSize;
+    }
+}
+
+
+/**
+ * Performs the raycasting and returns the final fragment color.
+ */
+vec4 performRaycasting(in vec3 entryPoint, in vec3 exitPoint, in vec2 texCoords) {
+    vec4 result = vec4(0.0);
+    float firstHitT = -1.0;
+
+    // calculate ray parameters
+    vec3 direction = exitPoint.rgb - entryPoint.rgb;
+    float len = length(direction);
+    
+    // Adjust direction a bit to prevent division by zero
+    direction.x = (abs(direction.x) < 0.0001) ? 0.0001 : direction.x;
+    direction.y = (abs(direction.y) < 0.0001) ? 0.0001 : direction.y;
+    direction.z = (abs(direction.z) < 0.0001) ? 0.0001 : direction.z;    
+    OFFSET = (0.25 / (1 << _vhMaxMipMapLevel)); //< offset value used to avoid self-intersection or previous voxel intersection.
+
+    float t = clipFirstHitpoint(_voxelHierarchy, _vhMaxMipMapLevel, entryPoint, direction, 0.0, 1.0);
+    float tend = 1.0 - clipFirstHitpoint(_voxelHierarchy, _vhMaxMipMapLevel, exitPoint, -direction, 0.0, 1.0);
+    jitterEntryPoint(entryPoint, direction, _samplingStepSize * _jitterStepSizeMultiplier);
+
+    ivec2 icPositionPrev = calcIcSamplePosition(textureToWorld(_volumeTextureParams, entryPoint.rgb + t * direction));
+    float icIn = imageLoad(_icImageIn, icPositionPrev).r;
+    float icOut = (0.0);
+    bool toBeSaved = false;
+
+    while (t < tend) {
+        // compute sample position
+        vec3 samplePosition = entryPoint.rgb + t * direction;
+        vec3 worldPos = textureToWorld(_volumeTextureParams, samplePosition);
+        ivec2 icPosition = calcIcSamplePosition(worldPos);
+
+        // optimization: Only store/load when the icPosition has changed
+        // otherwise we can reuse the variables from the previous sample
+        if (icPositionPrev != icPosition) {
+            // write illumination information
+            if (toBeSaved)
+                imageStore(_icImageOut, icPositionPrev, vec4(icOut));
+            toBeSaved = false;
+            
+            // load illumination information
+            icIn = imageLoad(_icImageIn, icPosition).r;
+
+            // perform a compositing from samplePosition to the samplePosition of the IC
+            // Currently disabled since it leads to ringing artifacts...
+            //if (icIn.xyz != vec3(0.0))
+            //    composite(samplePosition, icIn.xyz, icIn.a);
+        }
+
+        // lookup intensity and TF
+        float intensity = texture(_volume, samplePosition).r;
+        vec4 color = lookupTF(_transferFunction, _transferFunctionParams, intensity);
+
+        // perform compositing
+        if (color.a > 0.0) {
+            // compute gradient (needed for shading and normals)
+            vec3 gradient = computeGradient(_volume, _volumeTextureParams, samplePosition);            
+
+            // accomodate for variable sampling rates
+            color.a = 1.0 - pow(1.0 - color.a, _samplingStepSize * SAMPLING_BASE_INTERVAL_RCP);
+
+            // perform global illumination
+            // back-to-front compositing from light-direction 
+            // (for now, we ignore the color contribution and store the world position instead)
+            // icOut.rgb = ((1.0 - color.a) * icIn.rgb) + (color.a * color.rgb);
+            //icOut.xyz = samplePosition;
+            icOut   = ((1.0 - color.a) * icIn) + color.a;
+            toBeSaved = true;
+
+            // apply shadowing
+            const vec3 ambientColorOverride = _lightSource._ambientColor * (1.0 - icIn * _shadowIntensity);
+            color.rgb = calculatePhongShading(worldPos, ambientColorOverride, _lightSource, _cameraPosition, gradient, color.rgb);
+
+            // front-to-back compositing along view direction
+            result.rgb = result.rgb + color.rgb * color.a  * (1.0 - result.a);
+            result.a = result.a + (1.0 -result.a) * color.a;
+
+            icPositionPrev = icPosition;
+        }
+
+        // save first hit ray parameter for depth value calculation
+        if (firstHitT < 0.0 && result.a > 0.0) {
+            firstHitT = t;
+            out_FHP = vec4(samplePosition, 1.0);
+            out_FHN = vec4(icPosition, 0.0, 0.0);// vec4(normalize(computeGradient(_volume, _volumeTextureParams, samplePosition)), 1.0);
+        }
+
+        // early ray termination (disabled!)
+        //if (result.a > 0.975) {
+        //    result.a = 1.0;
+        //    t = tend;
+        //}
+
+        // advance to the next evaluation point along the ray
+        t += _samplingStepSize / len;
+    }
+
+    if (toBeSaved)
+        imageStore(_icImageOut, icPositionPrev, vec4(icOut));
+
+    // calculate depth value from ray parameter
+    gl_FragDepth = 1.0;
+    if (firstHitT >= 0.0) {
+        float depthEntry = texture(_entryPointsDepth, texCoords).z;
+        float depthExit = texture(_exitPointsDepth, texCoords).z;
+        gl_FragDepth = calculateDepthValue(firstHitT/tend, depthEntry, depthExit);
+    }
+
+    return result;
+}
+
+/***
+ * The main method.
+ ***/
+void main() {
+    vec2 p = gl_FragCoord.xy * _viewportSizeRCP;
+    vec3 frontPos = texture(_entryPoints, p).rgb;
+    vec3 backPos = texture(_exitPoints, p).rgb;
+
+    //determine whether the ray has to be casted
+    if (frontPos == backPos) {
+        //background need no raycasting
+        discard;
+    } else {
+        //fragCoords are lying inside the boundingbox
+        out_Color = performRaycasting(frontPos, backPos, p);
+    }
+}
+ 
\ No newline at end of file

modules/vis/pipelines/volumerendererdemo.cpp

@@ -67,7 +67,7 @@ namespace campvis {
         dvrTF->addGeometry(TFGeometry1D::createQuad(cgt::vec2(.19f, .28f), cgt::col4(89, 89, 89, 155), cgt::col4(89, 89, 89, 155)));
         dvrTF->addGeometry(TFGeometry1D::createQuad(cgt::vec2(.41f, .51f), cgt::col4(170, 170, 128, 64), cgt::col4(192, 192, 128, 64)));
         static_cast<TransferFunctionProperty*>(_vr.getNestedProperty("RaycasterProps::TransferFunction"))->replaceTF(dvrTF);
-        static_cast<FloatProperty*>(_vr.getNestedProperty("RaycasterProps::SamplingRate"))->setValue(4.f);
+        static_cast<FloatProperty*>(_vr.getNestedProperty("RaycasterProps::SamplingRate"))->setValue(2.f);
     }
 
 }
\ No newline at end of file

modules/vis/processors/advoptimizedraycaster.cpp

@@ -55,8 +55,6 @@ namespace campvis {
     }
 
     void AdvOptimizedRaycaster::init() {
-
-
         RaycastingProcessor::init();
 
         _vhm = new VoxelHierarchyMapper();
@@ -84,10 +82,6 @@ namespace campvis {
         ScopedTypedData<LightSourceData> light(data, p_lightId.getValue());
 
         if (p_enableShading.getValue() == false || light != nullptr) {
-            // undo MIPMAP hack from RaycastingProcessor, as mipmapping results in artifacts during ray clipping...
-            if (image->getTexture()->getFilter() != cgt::Texture::LINEAR)
-                const_cast<cgt::Texture*>(image->getTexture())->setFilter(cgt::Texture::LINEAR);
-
             _shader->activate();
 
             cgt::TextureUnit xorUnit, bbvUnit;

modules/vis/processors/ipsviraycaster.cpp

+// ================================================================================================
+// 
+// This file is part of the CAMPVis Software Framework.
+// 
+// If not explicitly stated otherwise: Copyright (C) 2012-2015, all rights reserved,
+//      Christian Schulte zu Berge <christian.szb@in.tum.de>
+//      Chair for Computer Aided Medical Procedures
+//      Technische Universitaet Muenchen
+//      Boltzmannstr. 3, 85748 Garching b. Muenchen, Germany
+// 
+// For a full list of authors and contributors, please refer to the file "AUTHORS.txt".
+// 
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file 
+// except in compliance with the License. You may obtain a copy of the License at
+// 
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software distributed under the 
+// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
+// either express or implied. See the License for the specific language governing permissions 
+// and limitations under the License.
+// 
+// ================================================================================================
+
+#include "ipsviraycaster.h"
+
+#include "core/tools/quadrenderer.h"
+#include "core/datastructures/cameradata.h"
+#include "core/datastructures/lightsourcedata.h"
+#include "core/datastructures/renderdata.h"
+#include "core/datastructures/genericimagerepresentationlocal.h"
+#include "core/pipeline/processordecoratorgradient.h"
+
+#include "modules/vis/tools/voxelhierarchymapper.h"
+
+#include <tbb/tbb.h>
+
+namespace campvis {
+    const std::string IpsviRaycaster::loggerCat_ = "CAMPVis.modules.vis.IpsviRaycaster";
+
+    IpsviRaycaster::IpsviRaycaster(IVec2Property* viewportSizeProp)
+        : RaycastingProcessor(viewportSizeProp, "modules/vis/glsl/ipsviraycaster.frag", true, "440")
+        , p_lightId("LightId", "Input Light Source", "lightsource", DataNameProperty::READ)
+        , p_sweepLineWidth("SweepLineWidth", "Sweep Line Width", 2, 1, 32)
+        , p_icTextureSize("IcTextureSize", "Illumination Cache Texture Size", cgt::ivec2(512), cgt::ivec2(32), cgt::ivec2(2048))
+        , p_shadowIntensity("ShadowIntensity", "Shadow Intensity", .75f, 0.f, 1.f)
+        , _vhm(nullptr)
+        , _gl44Supported(false)
+    {
+        _icTextures[0] = nullptr;
+        _icTextures[1] = nullptr;
+
+        addProperty(p_lightId);
+        addProperty(p_sweepLineWidth);
+        addProperty(p_icTextureSize, INVALID_RESULT | INVALID_IC_TEXTURES);
+        addProperty(p_shadowIntensity);
+
+        setPropertyInvalidationLevel(p_transferFunction, INVALID_BBV | INVALID_RESULT);
+        setPropertyInvalidationLevel(p_sourceImageID, INVALID_BBV | INVALID_RESULT);
+
+        addDecorator(new ProcessorDecoratorGradient());
+        decoratePropertyCollection(this);
+    }
+
+    IpsviRaycaster::~IpsviRaycaster() {
+    }
+
+    void IpsviRaycaster::init() {
+        // get supported OpenGL version
+        // if OpenGL 4.4 is not supported, abort the initialization, since compiling the shader will fail.
+        _gl44Supported = (GpuCaps.getGlVersion() >= cgt::GpuCapabilities::GlVersion::CGT_GL_VERSION_4_4);
+        _gl44Supported &= (GpuCaps.getShaderVersion() >= cgt::GpuCapabilities::GlVersion::SHADER_VERSION_440);
+        if (! _gl44Supported) {
+            LERROR("This system does not support OpenGL 4.4, which is required for the IpsviRaycaster. Raycaster deactivated.");
+            return;
+        }
+
+        RaycastingProcessor::init();
+        _vhm = new VoxelHierarchyMapper();
+        invalidate(INVALID_BBV | INVALID_IC_TEXTURES);
+    }
+
+    void IpsviRaycaster::deinit() {
+        // nothing to deinitialize, if this processor has never been initialized.
+        if (!_gl44Supported)
+            return;
+
+        delete _vhm;
+        delete _icTextures[0];
+        delete _icTextures[</