add automatic shading type selection

sunwj · Aug 1, 2016 · 23b3b1a · 23b3b1a
1 parent fd20e37
commit 23b3b1a
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Showing 9 changed files with 70 additions and 14 deletions.
diff --git a/core/VolumeReader.cpp b/core/VolumeReader.cpp
@@ -67,13 +67,14 @@ void VolumeReader::Read(std::string filename)
     histogram.resize(histDims[0]);
     memcpy(&histogram[0], hist->GetOutput()->GetScalarPointer(), sizeof(uint32_t) * histDims[0]);
 
-    //auto imageGradientMagnitude = vtkSmartPointer<vtkImageGradientMagnitude>::New();
-    //imageGradientMagnitude->SetDimensionality(3);
-    //imageGradientMagnitude->SetInput(imageCast->GetOutput());
-    //imageGradientMagnitude->Update();
-    //auto magData = imageGradientMagnitude->GetOutput();
-    //auto magRange = magData->GetScalarRange();
-    //maxMagnitude = magRange[2];
+    auto imageGradientMagnitude = vtkSmartPointer<vtkImageGradientMagnitude>::New();
+    imageGradientMagnitude->SetDimensionality(3);
+    imageGradientMagnitude->SetInput(imageCast->GetOutput());
+    imageGradientMagnitude->Update();
+    auto magData = imageGradientMagnitude->GetOutput();
+    auto magRange = magData->GetScalarRange();
+    maxMagnitude = magRange[1];
+    std::cout<<maxMagnitude<<std::endl;
 
     //auto ptr = reinterpret_cast<unsigned short*>(data) + 60 * 512 * 512;
     //unsigned char* tmp = new unsigned char[512 * 512 * 3];
@@ -180,6 +181,7 @@ void VolumeReader::CreateDeviceVolume(cudaVolume* volume)
     cudaBBox bbox = cudaBBox(vmin, vmax);
 
     volume->Set(bbox, spacing, volumeTex);
+    volume->SetInvMaxMagnitude(1.f / maxMagnitude);
 }
 
 glm::vec3 VolumeReader::GetVolumeSize()

diff --git a/core/VolumeReader.h b/core/VolumeReader.h
@@ -47,6 +47,7 @@ class VolumeReader
     glm::vec3 spacing = glm::vec3(glm::uninitialize);
     glm::ivec3 dim = glm::ivec3(glm::uninitialize);
     char* volumeData = nullptr;
+    float maxMagnitude = 0.f;
 
     cudaArray* volumeArray = nullptr;
     cudaTextureObject_t volumeTex = 0;

diff --git a/core/cuda_volume.h b/core/cuda_volume.h
@@ -75,6 +75,14 @@ class cudaVolume
         return 1.f / bbox.invSize;
     }
 
+    __host__ __device__ void SetInvMaxMagnitude(float invMag) {invMaxMagnitude = invMag;}
+
+    __host__ __device__ float GetInvMaxMagnitude() const {return invMaxMagnitude;}
+
+    __host__ __device__ void SetGradientFactor(float g) {gradientFactor = g;}
+
+    __host__ __device__ float GetGradientFactor() const {return gradientFactor;}
+
 private:
     __device__ glm::vec3 GetNormalizedTexCoord(const glm::vec3& pointInWorld) const
     {
@@ -104,6 +112,8 @@ class cudaVolume
     cudaBBox bbox;
     cudaTextureObject_t tex;
     float densityScale;
+    float invMaxMagnitude;
+    float gradientFactor;
     glm::vec3 spacing;
     glm::vec3 invSpacing;
     glm::vec2 x_clip;

diff --git a/gui/canvas.cpp b/gui/canvas.cpp
@@ -14,6 +14,8 @@ Canvas::Canvas(const QGLFormat &format, QWidget *parent) : QGLWidget(format, par
     // render params
     renderParams.SetupHDRBuffer(WIDTH, HEIGHT);
     renderParams.traceDepth = 1;
+
+    deviceVolume.SetGradientFactor(0.5f);
 }
 
 Canvas::~Canvas()

diff --git a/gui/canvas.h b/gui/canvas.h
@@ -60,6 +60,13 @@ class Canvas : public QGLWidget
         ReStartRender();
     }
 
+    void SetGradientFactor(double g)
+    {
+        deviceVolume.SetGradientFactor(g);
+        setup_volume(deviceVolume);
+        ReStartRender();
+    }
+
     void SetScatterTimes(double val)
     {
         renderParams.traceDepth = val;

diff --git a/gui/mainwindow.cpp b/gui/mainwindow.cpp
@@ -74,6 +74,7 @@ void MainWindow::ConfigureTransferFunction()
     connect(tf, SIGNAL(Changed()), this, SLOT(onTransferFunctionChanged()));
 
     connect(ui->SliderWidget_DensityScale, SIGNAL(valueChanged(double)), this, SLOT(onDensityScaleChanged(double)));
+    connect(ui->SliderWidget_GradientFactor, SIGNAL(valueChanged(double)), this, SLOT(onGradientFactorChanged(double)));
 }
 
 void MainWindow::onTransferFunctionChanged()
@@ -472,3 +473,8 @@ void MainWindow::onDensityScaleChanged(double s)
 {
     canvas->SetDensityScale(s);
 }
+
+void MainWindow::onGradientFactorChanged(double g)
+{
+    canvas->SetGradientFactor(g);
+}
diff --git a/gui/mainwindow.h b/gui/mainwindow.h
@@ -44,6 +44,7 @@ private slots:
     void onTransferFunctionChanged();
     void onDensityScaleChanged(double s);
     void onScatterTimesChanged(double val);
+    void onGradientFactorChanged(double g);
 
     void onEnvLightUOffsetChanged(double u);
     void onEnvLightVOffsetChanged(double v);

diff --git a/gui/mainwindow.ui b/gui/mainwindow.ui
@@ -110,9 +110,9 @@
             <property name="geometry">
              <rect>
               <x>0</x>
-              <y>-144</y>
+              <y>-180</y>
               <width>363</width>
-              <height>730</height>
+              <height>766</height>
              </rect>
             </property>
             <layout class="QVBoxLayout" name="verticalLayout_3">
@@ -203,6 +203,30 @@
                   </item>
                  </layout>
                 </item>
+                <item>
+                 <layout class="QGridLayout" name="gridLayout_7">
+                  <item row="1" column="1">
+                   <widget class="ctkSliderWidget" name="SliderWidget_GradientFactor">
+                    <property name="singleStep">
+                     <double>0.010000000000000</double>
+                    </property>
+                    <property name="maximum">
+                     <double>1.000000000000000</double>
+                    </property>
+                    <property name="value">
+                     <double>0.500000000000000</double>
+                    </property>
+                   </widget>
+                  </item>
+                  <item row="1" column="0">
+                   <widget class="QLabel" name="label_21">
+                    <property name="text">
+                     <string>Gradient factor</string>
+                    </property>
+                   </widget>
+                  </item>
+                 </layout>
+                </item>
                 <item>
                  <widget class="ctkVTKScalarsToColorsWidget" name="opacityTransferFunc">
                   <property name="minimumSize">

diff --git a/pathtracer.cu b/pathtracer.cu
@@ -246,10 +246,13 @@ __global__ void kernel_pathtracer(const RenderParams renderParams, uint32_t hash
         glm::vec3 wi;
         float pdf = 0.f;
         ShadingType st;
-        if(vs.gradientMagnitude < 1e-3)
-            st = SHANDING_TYPE_ISOTROPIC;
-        else
+
+        auto gradientFactor = volume.GetGradientFactor();
+        auto Pbrdf = vs.color_opacity.a * (1.f - expf(-25.f * gradientFactor * gradientFactor * gradientFactor * vs.gradientMagnitude * 65535.f * volume.GetInvMaxMagnitude()));
+        if(curand_uniform(&rng) < Pbrdf)
             st = SHANDING_TYPE_BRDF;
+        else
+            st = SHANDING_TYPE_ISOTROPIC;
 
         L += T * estimate_direct_light(vs, rng, st);
 
@@ -258,9 +261,9 @@ __global__ void kernel_pathtracer(const RenderParams renderParams, uint32_t hash
         if(fmaxf(f.x, fmaxf(f.y, f.z)) > 0.f && pdf > 0.f)
         {
             if(st == SHANDING_TYPE_ISOTROPIC)
-                T *= f / pdf;
+                T *= f / (pdf * (1.f - Pbrdf));
             else
-                T *= f * cosTerm / pdf;
+                T *= f * cosTerm / (pdf * Pbrdf);
         }
 
         ray.orig = vs.ptInWorld;