Surface reconstruction from points (#112)

This revision includes four different kinds of surface reconstruction algorithms of points such as:
* Spherical representation (union of spheres)
* SPH blobby (metaball-like) [Müller et al., 2003]
* Zhu and Bridson's method [Zhu and Bridson, 2005]
* Anisotropic kernel [Yu and Turk, 2010]

Author: doyubkim

include/jet/anisotropic_points_to_implicit2.h

@@ -0,0 +1,59 @@
+// Copyright (c) 2017 Doyub Kim
+//
+// I am making my contributions/submissions to this project solely in my
+// personal capacity and am not conveying any rights to any intellectual
+// property of any third parties.
+
+#ifndef INCLUDE_JET_ANISOTROPIC_POINTS_TO_IMPLICIT2_H_
+#define INCLUDE_JET_ANISOTROPIC_POINTS_TO_IMPLICIT2_H_
+
+#include <jet/points_to_implicit2.h>
+
+namespace jet {
+
+//!
+//! \brief 2-D points-to-implicit converter using Anisotropic kernels.
+//!
+//! This class converts 2-D points to implicit surface using anisotropic kernels
+//! so that the kernels are oriented and stretched to reflect the point
+//! distribution more naturally (thus less bumps). The implementation is based
+//! on Yu and Turk's 2013 paper with some modifications.
+//!
+//! \see Yu, Jihun, and Greg Turk. "Reconstructing surfaces of particle-based
+//!      fluids using anisotropic kernels." ACM Transactions on Graphics (TOG)
+//!      32.1 (2013): 5.
+//!
+class AnisotropicPointsToImplicit2 final : public PointsToImplicit2 {
+ public:
+    //!
+    //! \brief Constructs the converter with given parameters.
+    //!
+    //! \param kernelRadius Kernel radius for interpolations.
+    //! \param cutOffDensity Iso-contour density value.
+    //! \param positionSmoothingFactor Position smoothing factor.
+    //! \param minNumNeighbors Minimum number of neighbors to enable anisotropic
+    //!                        kernel.
+    //!
+    AnisotropicPointsToImplicit2(double kernelRadius = 1.0,
+                                 double cutOffDensity = 0.5,
+                                 double positionSmoothingFactor = 0.0,
+                                 size_t minNumNeighbors = 8);
+
+    //! Converts the given points to implicit surface scalar field.
+    void convert(const ConstArrayAccessor1<Vector2D>& points,
+                 ScalarGrid2* output) const override;
+
+ private:
+    double _kernelRadius = 1.0;
+    double _cutOffDensity = 0.5;
+    double _positionSmoothingFactor = 0.0;
+    size_t _minNumNeighbors = 8;
+};
+
+//! Shared pointer for the AnisotropicPointsToImplicit2 type.
+typedef std::shared_ptr<AnisotropicPointsToImplicit2>
+    AnisotropicPointsToImplicit2Ptr;
+
+}  // namespace jet
+
+#endif  // INCLUDE_JET_ANISOTROPIC_POINTS_TO_IMPLICIT2_H_

include/jet/anisotropic_points_to_implicit3.h

@@ -0,0 +1,59 @@
+// Copyright (c) 2017 Doyub Kim
+//
+// I am making my contributions/submissions to this project solely in my
+// personal capacity and am not conveying any rights to any intellectual
+// property of any third parties.
+
+#ifndef INCLUDE_JET_ANISOTROPIC_POINTS_TO_IMPLICIT3_H_
+#define INCLUDE_JET_ANISOTROPIC_POINTS_TO_IMPLICIT3_H_
+
+#include <jet/points_to_implicit3.h>
+
+namespace jet {
+
+//!
+//! \brief 3-D points-to-implicit converter using Anisotropic kernels.
+//!
+//! This class converts 3-D points to implicit surface using anisotropic kernels
+//! so that the kernels are oriented and stretched to reflect the point
+//! distribution more naturally (thus less bumps). The implementation is based
+//! on Yu and Turk's 2013 paper with some modifications.
+//!
+//! \see Yu, Jihun, and Greg Turk. "Reconstructing surfaces of particle-based
+//!      fluids using anisotropic kernels." ACM Transactions on Graphics (TOG)
+//!      32.1 (2013): 5.
+//!
+class AnisotropicPointsToImplicit3 final : public PointsToImplicit3 {
+ public:
+    //!
+    //! \brief Constructs the converter with given parameters.
+    //!
+    //! \param kernelRadius Kernel radius for interpolations.
+    //! \param cutOffDensity Iso-contour density value.
+    //! \param positionSmoothingFactor Position smoothing factor.
+    //! \param minNumNeighbors Minimum number of neighbors to enable anisotropic
+    //!                        kernel.
+    //!
+    AnisotropicPointsToImplicit3(double kernelRadius = 1.0,
+                                 double cutOffDensity = 0.5,
+                                 double positionSmoothingFactor = 0.0,
+                                 size_t minNumNeighbors = 25);
+
+    //! Converts the given points to implicit surface scalar field.
+    void convert(const ConstArrayAccessor1<Vector3D>& points,
+                 ScalarGrid3* output) const override;
+
+ private:
+    double _kernelRadius = 1.0;
+    double _cutOffDensity = 0.5;
+    double _positionSmoothingFactor = 0.0;
+    size_t _minNumNeighbors = 25;
+};
+
+//! Shared pointer for the AnisotropicPointsToImplicit3 type.
+typedef std::shared_ptr<AnisotropicPointsToImplicit3>
+    AnisotropicPointsToImplicit3Ptr;
+
+}  // namespace jet
+
+#endif  // INCLUDE_JET_ANISOTROPIC_POINTS_TO_IMPLICIT3_H_

include/jet/bounding_box2.h

@@ -108,6 +108,9 @@ class BoundingBox<T, 2> {
 
     //! Returns the clamped point.
     Vector2<T> clamp(const Vector2<T>& pt) const;
+
+    //! Returns true if the box is empty.
+    bool isEmpty() const;
 };
 
 //! Type alias for 2-D BoundingBox.

include/jet/bounding_box3.h

@@ -111,6 +111,9 @@ class BoundingBox<T, 3> {
 
     //! Returns the clamped point.
     Vector3<T> clamp(const Vector3<T>& point) const;
+
+    //! Returns true if the box is empty.
+    bool isEmpty() const;
 };
 
 //! Type alias for 3-D BoundingBox.

include/jet/detail/bounding_box2-inl.h

@@ -199,6 +199,11 @@ Vector2<T> BoundingBox<T, 2>::clamp(const Vector2<T>& pt) const {
     return ::jet::clamp(pt, lowerCorner, upperCorner);
 }
 
+template <typename T>
+bool BoundingBox<T, 2>::isEmpty() const {
+    return (lowerCorner.x >= upperCorner.x || lowerCorner.y >= upperCorner.y);
+}
+
 }  // namespace jet
 
 #endif  // INCLUDE_JET_DETAIL_BOUNDING_BOX2_INL_H_

include/jet/detail/bounding_box3-inl.h

@@ -212,6 +212,12 @@ Vector3<T> BoundingBox<T, 3>::clamp(const Vector3<T>& pt) const {
     return ::jet::clamp(pt, lowerCorner, upperCorner);
 }
 
+template <typename T>
+bool BoundingBox<T, 3>::isEmpty() const {
+    return (lowerCorner.x >= upperCorner.x || lowerCorner.y >= upperCorner.y ||
+            lowerCorner.z >= upperCorner.z);
+}
+
 }  // namespace jet
 
 #endif  // INCLUDE_JET_DETAIL_BOUNDING_BOX3_INL_H_