Screen space ambient occlusion effect added

Source/Rendering/VTKRenderer/imstkVTKRenderer.cpp

@@ -48,6 +48,11 @@
 
 #include <vtkOpenVRRenderer.h>
 #include <vtkOpenVRCamera.h>
+#include <vtkShadowMapBakerPass.h>
+#include <vtkShadowMapPass.h>
+#include <vtkSequencePass.h>
+#include <vtkCameraPass.h>
+#include <vtkRenderPassCollection.h>
 
 namespace imstk
 {
@@ -226,6 +231,11 @@ VTKRenderer::VTKRenderer(std::shared_ptr<Scene> scene, const bool enableVR) :
         axisY->SetGridVisible(false);
         axisY->SetCustomTickPositions(xIndices, labels);
     }
+
+    // Prepare screen space ambient occlusion effect
+    vtkNew<vtkRenderStepsPass> basicPasses;
+    ssao->SetDelegatePass(basicPasses);
+
 }
 
 void
@@ -382,6 +392,12 @@ VTKRenderer::getTimeTableVisibility() const
     return m_timeTableChartActor->GetVisibility();
 }
 
+ssaoConfig
+VTKRenderer::getSSAOConfig() const
+{
+    return m_config->m_ssaoConfig;
+}
+
 void
 VTKRenderer::updateCamera()
 {
@@ -610,4 +626,30 @@ VTKRenderer::updateBackground(const Vec3d backgroundOne, const Vec3d backgroundT
         m_vtkRenderer->GradientBackgroundOff();
     }
 }
+
+void
+VTKRenderer::updateSSAOConfig(ssaoConfig config)
+{
+    m_config->m_ssaoConfig = config; // update config
+
+    ssao->SetRadius(config.m_SSAORadius); // comparison radius
+    ssao->SetBias(config.m_SSAOBias); // comparison bias
+    ssao->SetKernelSize(config.m_KernelSize); // number of samples used
+
+    if (config.m_SSAOBlur)
+    {
+        ssao->BlurOn(); // blur occlusion
+    }
+    else
+    {
+        ssao->BlurOff(); // do not blur occlusion
+    }
+
+    if (config.m_enableSSAO) {
+        m_vtkRenderer->SetPass(ssao);
+    }
+    else {
+        m_vtkRenderer->SetPass(NULL);
+    }
+}
 } // imstk

Source/Rendering/VTKRenderer/imstkVTKRenderer.h

@@ -27,6 +27,8 @@
 #include "imstkEventObject.h"
 
 #include <vtkSmartPointer.h>
+#include <vtkRenderStepsPass.h>
+#include <vtkSSAOPass.h>
 #include <unordered_map>
 #include <unordered_set>
 
@@ -102,6 +104,11 @@ public:
     ///
     bool getTimeTableVisibility() const;
 
+    ///
+    /// \brief Update SSAO options
+    ///
+    ssaoConfig getSSAOConfig() const;
+
     ///
     /// \brief Updates the camera
     ///
@@ -127,6 +134,11 @@ public:
     ///
     void updateBackground(const Vec3d color1, const Vec3d color2 = Vec3d::Zero(), const bool gradientBackground = false);
 
+    ///
+    /// \brief Update SSAO options
+    ///
+    void updateSSAOConfig(ssaoConfig config);
+
 protected:
     ///
     /// \brief Remove actors (also called props) from the scene
@@ -210,5 +222,8 @@ protected:
     vtkSmartPointer<vtkTable> m_timeTable;
     vtkPlotBar* m_timeTablePlot;
     int m_timeTableIter = 0;
+
+    // SSAO Effect
+    vtkNew<vtkSSAOPass> ssao;
 };
 }

Source/Rendering/imstkRenderer.h

@@ -27,12 +27,24 @@
 
 namespace imstk
 {
+
+struct ssaoConfig {
+    bool m_enableSSAO = false;
+    bool m_SSAOBlur = false; // blur occlusion
+    double m_SSAORadius = 0.1; // comparison radius
+    double m_SSAOBias = 0.001; // comparison bias
+    unsigned int m_KernelSize = 128; // number of samples used
+};
+
 struct rendererConfig
 {
     bool m_enableVR = false;
 
     Color m_BGColor1 = Color(0.3285, 0.3285, 0.6525);
     Color m_BGColor2 = Color(0.13836, 0.13836, 0.2748);
+
+    // ScreenSpace Ambient Occlusion
+    ssaoConfig m_ssaoConfig;
 };
 
 ///