OpenVDB 12.1.0
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ConvexVoxelizer< GridType, Derived, InterruptType > Class Template Reference

Base class used to generate a grid of type GridType containing a narrow-band level set representation of a convex region. More...

#include <openvdb/tools/impl/ConvexVoxelizer.h>

Classes

class  XYRangeData
 Class that stores endpoints of a y range for each x value within a specified range and step size. More...

Public Member Functions

 ConvexVoxelizer (GridPtr &grid, const bool &threaded=false, InterruptType *interrupter=nullptr)
 Constructor.
virtual ~ConvexVoxelizer ()=default
ValueT voxelSize () const
 Return the voxel size of the grid.
ValueT halfWidth () const
 Return the half width of the narrow-band level set.

Protected Types

using ValueT = typename GridType::ValueType
using Vec3T = math::Vec3<ValueT>
using Vec2T = math::Vec2<ValueT>

Protected Member Functions

void iterate ()
 The function the derived class calls to create the level set, working in index space other than setting signed distance values.
void setXYRangeData (const Index &)
 Determines the x bounds in index space of the convex region dilated by the half width. For each x value in index space, the y range in index space of the dilated region is computed. This function should store the data in mXYData.
bool tileCanFit (const Index &) const
 Checks if the tile of a given dimension can possibly fit within the region.
ValueT signedDistance (const Vec3T &) const
 Computes the signed distance from a point to the convex region in index space.
ValueT tilePointSignedDistance (const Vec3T &p) const
 Computes the signed distance for tiles in index space, considering the center of the tile. This method is optional to override and defaults to signedDistance.

Static Protected Member Functions

static ValueT tileCeil (const ValueT &x, const ValueT &step)
 Rounds an input scalar up to the nearest valid ordinate of tile of a specified size.
template<typename T>
static ValueT tileCeil (const ValueT &x, const T &step)
 Rounds an input scalar up to the nearest valid ordinate of tile of a specified size.
static ValueT tileFloor (const ValueT &x, const ValueT &step)
 Rounds an input scalar down to the nearest valid ordinate of tile of a specified size.
template<typename T>
static ValueT tileFloor (const ValueT &x, const T &step)
 Rounds an input scalar down to the nearest valid ordinate of tile of a specified size.
static ValueT circleBottom (const ValueT &x0, const ValueT &y0, const ValueT &r, const ValueT &x)
 Computes the bottom y-coordinate of a circle at a given x position.
static ValueT circleTop (const ValueT &x0, const ValueT &y0, const ValueT &r, const ValueT &x)
 Computes the top y-coordinate of a circle at a given x position.
static ValueT sphereBottom (const ValueT &x0, const ValueT &y0, const ValueT &z0, const ValueT &r, const ValueT &x, const ValueT &y)
 Computes the bottom z-coordinate of a sphere at a given (x, y) position.
static ValueT sphereTop (const ValueT &x0, const ValueT &y0, const ValueT &z0, const ValueT &r, const ValueT &x, const ValueT &y)
 Computes the top z-coordinate of a sphere at a given (x, y) position.

Protected Attributes

std::function< bool(ValueT &, ValueT &, const ValueT &, const ValueT &)> bottomTop
 Find where a vertical infinite line intersects a convex region dilated by the half width.
XYRangeData mXYData

Detailed Description

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
class openvdb::v12_1::tools::ConvexVoxelizer< GridType, Derived, InterruptType >

Base class used to generate a grid of type GridType containing a narrow-band level set representation of a convex region.

Note
GridType::ValueType must be a floating-point scalar.
Derived is the derived class that implements the base class (curiously recurring template pattern).
Example of derived level set sphere class
template <typename GridType>
class SphereVoxelizer : public ConvexVoxelizer<GridType, SphereVoxelizer<GridType>>
{
using GridPtr = typename GridType::Ptr;
using BaseT::mXYData;
using BaseT::tileCeil;
using ValueT = typename BaseT::ValueT;
using Vec3T = typename BaseT::Vec3T;
public:
friend class ConvexVoxelizer<GridType, SphereVoxelizer<GridType>>;
SphereVoxelizer(GridPtr& grid, const bool& threaded = true)
: BaseT(grid, threaded)
{
}
template <typename ScalarT>
void
operator()(const math::Vec3<ScalarT>& pt, const ScalarT& r)
{
static_assert(std::is_floating_point<ScalarT>::value);
if (r <= 0)
return;
BaseT::iterate();
}
private:
inline ValueT
signedDistance(const Vec3T& p) const
{
return (p - mPt).length() - mRad;
}
inline void
setXYRangeData(const Index& step = 1)
{
mXYData.reset(mX - mORad, mX + mORad, step);
for (ValueT x = tileCeil(mX - mORad, step); x <= mX + mORad; x += step)
mXYData.expandYRange(x, BaseT::circleBottom(mX, mY, mORad, x),
BaseT::circleTop(mX, mY, mORad, x));
}
std::function<bool(ValueT&, ValueT&, const ValueT&, const ValueT&)> sphereBottomTop =
[this](ValueT& zb, ValueT& zt, const ValueT& x, const ValueT& y)
{
zb = BaseT::sphereBottom(mX, mY, mZ, mORad, x, y);
zt = BaseT::sphereTop(mX, mY, mZ, mORad, x, y);
return std::isfinite(zb) && std::isfinite(zt);
};
template <typename ScalarT>
inline void
initialize(const math::Vec3<ScalarT>& pt, const ScalarT& r)
{
const ValueT vx = BaseT::voxelSize(),
hw = BaseT::halfWidth();
// sphere data in index space
mPt = Vec3T(pt)/vx;
mRad = ValueT(r)/vx;
mX = mPt.x(); mY = mPt.y(); mZ = mPt.z();
// padded radius used to populate the outer halfwidth of the sdf
mORad = mRad + hw;
BaseT::bottomTop = sphereBottomTop;
}
Vec3T mPt;
ValueT mRad, mORad, mX, mY, mZ;
};
// usage:
// initialize level set grid with voxel size 0.1 and half width 3.0
// populate grid with a sphere centered at (0, 1, 2) and radius 5
SphereVoxelizer<FloatGrid> op(grid);
op(Vec3s(0.0f, 1.0f, 2.0f), 5.0f);
SharedPtr< Grid > Ptr
Definition Grid.h:573
Definition Vec3.h:25
T & x()
Reference to the component, e.g. v.x() = 4.5f;.
Definition Vec3.h:86
void reset(const ValueT &xmin, const ValueT &xmax, const Index &step=1)
Resets the x range to span a given interval with a specific step size. This initializes all y ranges ...
Definition ConvexVoxelizer.h:577
void expandYRange(const ValueT &x, const ValueT &ymin, const ValueT &ymax)
Expands the y range for a given x value by updating the minimum and maximum y values if the new ones ...
Definition ConvexVoxelizer.h:470
static ValueT tileCeil(const ValueT &x, const ValueT &step)
Rounds an input scalar up to the nearest valid ordinate of tile of a specified size.
Definition ConvexVoxelizer.h:327
math::Vec3< ValueT > Vec3T
Definition ConvexVoxelizer.h:185
typename GridType::ValueType ValueT
Definition ConvexVoxelizer.h:184
void setXYRangeData(const Index &)
Determines the x bounds in index space of the convex region dilated by the half width....
Definition ConvexVoxelizer.h:272
XYRangeData mXYData
Definition ConvexVoxelizer.h:780
ConvexVoxelizer(GridPtr &grid, const bool &threaded=false, InterruptType *interrupter=nullptr)
Constructor.
Definition ConvexVoxelizer.h:201
ValueT signedDistance(const Vec3T &) const
Computes the signed distance from a point to the convex region in index space.
Definition ConvexVoxelizer.h:290
Vec3< float > Vec3s
Definition Vec3.h:664
OutGridT const XformOp bool bool
Definition ValueTransformer.h:610
OutGridT XformOp & op
Definition ValueTransformer.h:140
OutGridT XformOp bool threaded
Definition ValueTransformer.h:140
Index32 Index
Definition Types.h:54
OPENVDB_IMPORT void initialize()
Global registration of native Grid, Transform, Metadata and Point attribute types....
GridType::Ptr createLevelSet(Real voxelSize=1.0, Real halfWidth=LEVEL_SET_HALF_WIDTH)
Create a new grid of type GridType classified as a "Level Set", i.e., a narrow-band level set.
Definition Grid.h:1782

Member Typedef Documentation

◆ ValueT

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
using ValueT = typename GridType::ValueType
protected

◆ Vec2T

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
using Vec2T = math::Vec2<ValueT>
protected

◆ Vec3T

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
using Vec3T = math::Vec3<ValueT>
protected

Constructor & Destructor Documentation

◆ ConvexVoxelizer()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ConvexVoxelizer ( GridPtr & grid,
const bool & threaded = false,
InterruptType * interrupter = nullptr )
inline

Constructor.

Parameters
gridscalar grid to populate the level set in
threadedcenter of the sphere in world units
interrupterpointer to optional interrupter. Use template argument util::NullInterrupter if no interruption is desired.
Note
The voxel size and half width are determined from the input grid, meaning the voxel size and background value need to be set prior to voxelization

◆ ~ConvexVoxelizer()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
virtual ~ConvexVoxelizer ( )
virtualdefault

Member Function Documentation

◆ circleBottom()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ValueT circleBottom ( const ValueT & x0,
const ValueT & y0,
const ValueT & r,
const ValueT & x )
inlinestaticprotected

Computes the bottom y-coordinate of a circle at a given x position.

Parameters
x0X-coordinate of the circle's center.
y0Y-coordinate of the circle's center.
rRadius of the circle.
xX-coordinate for which to compute the bottom y-coordinate.
Returns
The y-coordinate at the bottom of the circle for the given x position.

◆ circleTop()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ValueT circleTop ( const ValueT & x0,
const ValueT & y0,
const ValueT & r,
const ValueT & x )
inlinestaticprotected

Computes the top y-coordinate of a circle at a given x position.

Parameters
x0X-coordinate of the circle's center.
y0Y-coordinate of the circle's center.
rRadius of the circle.
xX-coordinate for which to compute the top y-coordinate.
Returns
The y-coordinate at the top of the circle for the given x position.

◆ halfWidth()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ValueT halfWidth ( ) const
inline

Return the half width of the narrow-band level set.

◆ iterate()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
void iterate ( )
inlineprotected

The function the derived class calls to create the level set, working in index space other than setting signed distance values.

Note
This function handles both parallel and serial iterations. If running in serial mode, it flood fills the tile topology immediately; otherwise, it avoids duplicating nontrivial tree topology over multiple threads. This method also checks for background tiles that are too thin to fit and delegates accordingly.

◆ setXYRangeData()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
void setXYRangeData ( const Index & )
inlineprotected

Determines the x bounds in index space of the convex region dilated by the half width. For each x value in index space, the y range in index space of the dilated region is computed. This function should store the data in mXYData.

Parameters
stepThe step size for setting the XY range data, defaults to 1.
Note
Function to be implemented by derived classes to set XY range data. This function is called at most 4 times within iterate().

◆ signedDistance()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ValueT signedDistance ( const Vec3T & ) const
inlineprotected

Computes the signed distance from a point to the convex region in index space.

Parameters
pThe point in 3D space for which to compute the signed distance.

◆ sphereBottom()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ValueT sphereBottom ( const ValueT & x0,
const ValueT & y0,
const ValueT & z0,
const ValueT & r,
const ValueT & x,
const ValueT & y )
inlinestaticprotected

Computes the bottom z-coordinate of a sphere at a given (x, y) position.

Parameters
x0X-coordinate of the sphere's center.
y0Y-coordinate of the sphere's center.
z0Z-coordinate of the sphere's center.
rRadius of the sphere.
xX-coordinate for which to compute the bottom z-coordinate.
yY-coordinate for which to compute the bottom z-coordinate.
Returns
The z-coordinate at the bottom of the sphere for the given (x, y) position.

◆ sphereTop()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ValueT sphereTop ( const ValueT & x0,
const ValueT & y0,
const ValueT & z0,
const ValueT & r,
const ValueT & x,
const ValueT & y )
inlinestaticprotected

Computes the top z-coordinate of a sphere at a given (x, y) position.

Parameters
x0X-coordinate of the sphere's center.
y0Y-coordinate of the sphere's center.
z0Z-coordinate of the sphere's center.
rRadius of the sphere.
xX-coordinate for which to compute the top z-coordinate.
yY-coordinate for which to compute the top z-coordinate.
Returns
The z-coordinate at the top of the sphere for the given (x, y) position.

◆ tileCanFit()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
bool tileCanFit ( const Index & ) const
inlineprotected

Checks if the tile of a given dimension can possibly fit within the region.

The derived class does not need to implement it if the default behavior is acceptable, which assumes a tile can always possibly fit.

Parameters
dimThe dimension of the tile in which to check if the tile fits.
Note
This is meant as a short-circuting method: if a tile of a given dimension can't fit then iterate will not try to populate the level set with background tiles of this dimension.
Returns
true if the tile can possibly fit; otherwise false.

◆ tileCeil() [1/2]

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
template<typename T>
ValueT tileCeil ( const ValueT & x,
const T & step )
inlinestaticprotected

Rounds an input scalar up to the nearest valid ordinate of tile of a specified size.

Template Parameters
TAny integral type (int, unsigned int, size_t, etc.)
Parameters
xInput value.
stepTile step size.
Returns
The ceiling of the value based on the tile size.

◆ tileCeil() [2/2]

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ValueT tileCeil ( const ValueT & x,
const ValueT & step )
inlinestaticprotected

Rounds an input scalar up to the nearest valid ordinate of tile of a specified size.

Parameters
xInput value.
stepTile step size.
Returns
The ceiling of the value based on the tile size.

◆ tileFloor() [1/2]

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
template<typename T>
ValueT tileFloor ( const ValueT & x,
const T & step )
inlinestaticprotected

Rounds an input scalar down to the nearest valid ordinate of tile of a specified size.

Template Parameters
TAny integral type (int, unsigned int, size_t, etc.)
Parameters
xInput value.
stepTile step size.
Returns
The ceiling of the value based on the tile size.

◆ tileFloor() [2/2]

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ValueT tileFloor ( const ValueT & x,
const ValueT & step )
inlinestaticprotected

Rounds an input scalar down to the nearest valid ordinate of tile of a specified size.

Parameters
xInput value.
stepTile step size.
Returns
The ceiling of the value based on the tile size.

◆ tilePointSignedDistance()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ValueT tilePointSignedDistance ( const Vec3T & p) const
inlineprotected

Computes the signed distance for tiles in index space, considering the center of the tile. This method is optional to override and defaults to signedDistance.

Parameters
pThe point at the center of the tile in 3D space.
Note
This can be useful for cases that build objects from multiple primitives, e.g. dilated mesh is built by constructing and unioning open prisms and open tube wedges. A tile might not fully fit in an open prism but might fit in the union of a prism and wedge, and so in this case it might make sense to use the sdf for an offset triangle on tiles during the open prism scan.

◆ voxelSize()

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
ValueT voxelSize ( ) const
inline

Return the voxel size of the grid.

Member Data Documentation

◆ bottomTop

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
std::function<bool(ValueT&, ValueT&, const ValueT&, const ValueT&)> bottomTop
protected
Initial value:
=
[](ValueT&, ValueT&, const ValueT&, const ValueT&) { return false; }

Find where a vertical infinite line intersects a convex region dilated by the half width.

Parameters
[out]zbReference to the z ordinate where the bottom intersection occurs.
[out]ztReference to the z ordinate where the top intersection occurs.
[in]xThe x ordinate of the infinte line.
[in]yThe y ordinate of the infinte line.
Returns
true if an intersection occurs; otherwise false.
Note
The derived class can override this lambda to implement different behavior for degenerate cases.

◆ mXYData

template<typename GridType, typename Derived, typename InterruptType = util::NullInterrupter>
XYRangeData mXYData
protected