maspack.geometry

Class VectorGrid<T extends VectorObject<T>>

java.lang.Object

maspack.geometry.InterpolatingGridBase

maspack.geometry.VectorGrid<T>

All Implemented Interfaces:

HasRenderProps, IsRenderable, IsSelectable, Renderable, ParameterizedClass, Scannable

Direct Known Subclasses:

MatrixNdGrid, VectorNdGrid

public class VectorGrid<T extends VectorObject<T>>
extends InterpolatingGridBase
implements ParameterizedClass

Implements a regular 3D grid that interpolates VectorObject values using trilinear interpolation. The VectorObjects used are assumed to be of a fixed size. For the variable sized objects VectorNd and MatrixNd, one should use VectorNdGrid and MatrixNdGrid instead.

The grid is implemented using a regular 3D grid composed of nx X ny X nz vertices along the x, y and z directions, giving the grid a resolution of rx, ry, rz, cells along each of these directions, where rx = nx-1, ry = ny-1, and rz = nz-1. The grid has widths w = (wx, wy, wz) along each of these directions, and cell widths given by wx/rx, wy/ry, and wz/rz.

Several coordinate frames are associated with the grid: the local frame L, the world frame W, and the grid frame G. Details on these are given in the documentation for InterpolatingGridBase.

Values at any point within the grid are be obtained by trilinear interpolation of the values at surrounding vertices. Queries can be made for points in either local or world coordinates, using getLocalValue(maspack.matrix.Point3d) or getWorldValue(maspack.matrix.Point3d). If the query point is outside the grid, then null is returned.

Values at the grid vertices can be assigned collectively or individually, using setVertexValues(T[]) or setVertexValue(int, T). Values at grid vertices can be queried using getVertexValue(int).

Field Summary

Fields inherited from interface maspack.render.IsRenderable

TRANSPARENT, TWO_DIMENSIONAL

Constructor Summary

Constructors

Constructor and Description
VectorGrid(java.lang.Class<T> type) This constructor should not be called by applications, unless InterpolatingGridBase.scan(maspack.util.ReaderTokenizer, java.lang.Object) is called immediately after.
VectorGrid(java.lang.Class<T> type, Vector3d widths, Vector3i resolution) Creates a new grid with specified widths and resolution, centered on the local coordinate system.
VectorGrid(java.lang.Class<T> type, Vector3d widths, Vector3i resolution, RigidTransform3d TCL) Creates a new grid with specified widths, resolution, and position and orientation of the center given by TCL.
VectorGrid(java.lang.Class<T> type, Vector3i resolution) Creates a new grid, axis-aligned and centered on the origin, with the specified resolution and x, y, z widths set to 1.
VectorGrid(VectorGrid<T> grid) Creates a new grid that is a copy of an existing grid.

Method Summary

Modifier and Type	Method and Description
T	createTypeInstance()
boolean	epsilonEquals(VectorGrid<T> grid, double tol) Returns true if this grid equals another within a prescribed tolerance.
T	getLocalValue(Point3d point) Calculates the value at an arbitrary point in local coordinates using multilinear interpolation of the vertex values for the grid cell containing the point.
T	getLocalValue(Point3d point, boolean clipToGrid) Calculates the value at an arbitrary point in local coordinates using multilinear interpolation of the vertex values for the grid cell containing the point.
java.lang.Class<T>	getParameterType() For subclasses with parameterized typing, returns the type parameter.
boolean	getRenderVector(Vector3d vec3, int xi, int yj, int zk) For grid subclasses wishing to render 3D vector information, this method should be overridden to optionally returns a vector quantity associated with the vertex at indices xi, yj, and zk.
double	getRenderVectorScale() For grid subclasses wishing to render 3D vector information, this method should be overridden to return a scaling factor to be applied to vectors returned by InterpolatingGridBase.getRenderVector(maspack.matrix.Vector3d, int, int, int) to determine the length of the actual rendered vector.
T	getVertexValue(int vi) Queries the value for the vertex indexed by vi.
T	getVertexValue(int xi, int yj, int zk) Queries the value at a specified vertex, as specified by x, y, z indices.
T	getVertexValue(Vector3i vxyz) Queries the value at a specified vertex, as specified by x, y, z indices.
java.util.ArrayList<T>	getVertexValues() Returns the internal array of the values at each vertex.
T	getWorldValue(Point3d point) Calculates the value at an arbitrary point in world coordinates using multilinear interpolation of the vertex values for the grid cell containing the point.
T	getWorldValue(Point3d point, boolean clipToGrid) Calculates the value at an arbitrary point in world coordinates using multilinear interpolation of the vertex values for the grid cell containing the point.
boolean	hasParameterizedType() Queries whether this class explicitly utilizes a parameterized type.
T	scanValue(ReaderTokenizer rtok) Scans and returns an instance of the vector type associated with this grid from a reader tokenizer.
void	set(VectorGrid<T> grid) Sets this grid to be a copy of an existing grid.
void	setRenderVectorScale(double scale)
void	setVertexValue(int xi, int yj, int zk, T value) Sets the value for the vertex indexed by its x, y, z indices.
void	setVertexValue(int vi, T value) Sets the value for the vertex indexed by vi.
void	setVertexValues(T[] values) Sets all the vertex values for this grid.
<S> void	writeValue(java.io.PrintWriter pw, NumberFormat fmt, T val) Writes a vector of the type associated with this grid to a PrintWriter.
void	zeroVertexValues() Zeros all the vertex values for this grid.

Methods inherited from class maspack.geometry.InterpolatingGridBase

clearColors, createRenderProps, epsilonEquals, getCellVertex, getCellWidths, getCenter, getCenterAndOrientation, getClosestVertex, getDebug, getDefaultVertexColor, getGridToLocalTransformer, getLocalToWorld, getLocalToWorldTransformer, getLocalVertexCoords, getLocalVertexCoords, getOrientation, getRadius, getRenderHints, getRenderProps, getRenderRanges, getResolution, getSelection, getVertexColor, getWidths, getWidths, getWorldCenter, getWorldOrientation, getWorldVertexCoords, getWorldVertexCoords, hasLocalToWorld, isSelectable, isVertexRenderingEnabled, isWritable, numSelectionQueriesNeeded, numVertices, parseRenderRanges, prerender, prerender, render, render, scaleDistance, scan, set, setCenter, setCenterAndOrientation, setDebug, setDefaultVertexColor, setLocalToWorld, setOrientation, setRenderProps, setRenderRanges, setResolution, setVertexColor, setVertexRenderingEnabled, updateBounds, vertexToXyzIndices, write, xyzIndicesToVertex

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VectorGrid

public VectorGrid(java.lang.Class<T> type)

This constructor should not be called by applications, unless InterpolatingGridBase.scan(maspack.util.ReaderTokenizer, java.lang.Object) is called immediately after.

VectorGrid

public VectorGrid(java.lang.Class<T> type,
                  Vector3d widths,
                  Vector3i resolution)

Creates a new grid with specified widths and resolution, centered on the local coordinate system. The grid values are initialized to zero.

Parameters:

type - class type for the VectorObject associated with this grid.

widths - widths along the x, y, and z axes

resolution - cell resolution along the x, y, and z axes

VectorGrid

public VectorGrid(java.lang.Class<T> type,
                  Vector3d widths,
                  Vector3i resolution,
                  RigidTransform3d TCL)

Creates a new grid with specified widths, resolution, and position and orientation of the center given by TCL. The grid values are initialized to zero.

Parameters:

type - class type for the VectorObject associated with this grid.

widths - widths along the x, y, and z axes

resolution - cell resolution along the x, y, and z axes

TCL - if not null, describes the position and orientation of the grid center in local coordinates.

VectorGrid

public VectorGrid(java.lang.Class<T> type,
                  Vector3i resolution)

Creates a new grid, axis-aligned and centered on the origin, with the specified resolution and x, y, z widths set to 1. The grid values are initialized to zero.

Parameters:

type - class type for the VectorObject associated with this grid.

resolution - cell resolution along the x, y, and z axes

VectorGrid

public VectorGrid(VectorGrid<T> grid)

Creates a new grid that is a copy of an existing grid.

Parameters:

grid - grid to copy

Method Detail

createTypeInstance

public T createTypeInstance()

getParameterType

public java.lang.Class<T> getParameterType()

For subclasses with parameterized typing, returns the type parameter. Othewise, returns null.

Specified by:

getParameterType in interface ParameterizedClass

Specified by:

getParameterType in class InterpolatingGridBase

Returns:

type parameter, or null

hasParameterizedType

public boolean hasParameterizedType()

Queries whether this class explicitly utilizes a parameterized type. This methods allows ParameterizedType subclasses to not be explicitly parameterized.

Specified by:

hasParameterizedType in interface ParameterizedClass

Returns:

true if this class utilizes a parameterized type.

set

public void set(VectorGrid<T> grid)

Sets this grid to be a copy of an existing grid.

Parameters:

grid - grid to copy

setVertexValues

public void setVertexValues(T[] values)

Sets all the vertex values for this grid. The input array is indexed such that for vertex indices xi, yj, zk, the corresponding index into this array is

 idx = xi + nx*yj + (nx*ny)*zk
 

where nx and ny are the number of vertices along x and y axes.

The input values are copied internally and are not referenced by the grid.

Parameters:

values - value for each vertex. Must have a length >= InterpolatingGridBase.numVertices().

getVertexValues

public java.util.ArrayList<T> getVertexValues()

Returns the internal array of the values at each vertex. See setVertexValues(T[]) for a description of how vertices are indexed with respect to this array.

The returned values are those referenced directly by the grid.

Returns:

array of vertex values.

setVertexValue

public void setVertexValue(int vi,
                           T value)

Sets the value for the vertex indexed by vi. See setVertexValues(T[]) for a description of how vertices are indexed.

The input value is copied internally and is not referenced by the grid.

Parameters:

vi - vertex index

value - vertex value

setVertexValue

public void setVertexValue(int xi,
                           int yj,
                           int zk,
                           T value)

Sets the value for the vertex indexed by its x, y, z indices.

Parameters:

xi - x vertex index

yj - y vertex index

zk - z vertex index

value - new value for the vertex

getVertexValue

public T getVertexValue(int vi)

Queries the value for the vertex indexed by vi. See setVertexValues(T[]) for a description of how vertices are indexed.

The returned value is the internal value referenced by the grid.

Parameters:

vi - vertex index

Returns:

value at vertex

getVertexValue

public T getVertexValue(Vector3i vxyz)

Queries the value at a specified vertex, as specified by x, y, z indices.

The returned value is the internal value referenced by the grid.

Parameters:

vxyz - x, y, z vertex indices

Returns:

value at the vertex

getVertexValue

public T getVertexValue(int xi,
                        int yj,
                        int zk)

Queries the value at a specified vertex, as specified by x, y, z indices.

The returned value is the internal value referenced by the grid.

Parameters:

xi - x vertex index

yj - y vertex index

zk - z vertex index

Returns:

value at the vertex

zeroVertexValues

public void zeroVertexValues()

Zeros all the vertex values for this grid.

getWorldValue

public T getWorldValue(Point3d point)

Calculates the value at an arbitrary point in world coordinates using multilinear interpolation of the vertex values for the grid cell containing the point. If the point lies outside the grid volume, null is returned.

Parameters:

point - point at which to calculate the value (world coordinates)

Returns:

interpolated value, or null

getWorldValue

public T getWorldValue(Point3d point,
                       boolean clipToGrid)

Calculates the value at an arbitrary point in world coordinates using multilinear interpolation of the vertex values for the grid cell containing the point. If the point lies outside the grid volume, then the method returns either the nearest grid value or null, depending on whether clipToGrid is true or false.

Parameters:

point - point at which to calculate the value (world coordinates)

clipToGrid - if true, return the nearest grid value if point is outside the grid volume

Returns:

interpolated value, or null

getLocalValue

public T getLocalValue(Point3d point)

Calculates the value at an arbitrary point in local coordinates using multilinear interpolation of the vertex values for the grid cell containing the point. If the point lies outside the grid volume, null is returned.

Parameters:

point - point at which to calculate the normal and value (local coordinates)

Returns:

interpolated value, or null

getLocalValue

public T getLocalValue(Point3d point,
                       boolean clipToGrid)

Calculates the value at an arbitrary point in local coordinates using multilinear interpolation of the vertex values for the grid cell containing the point. If the point lies outside the grid volume, then the method returns either the nearest grid value or null, depending on whether clipToGrid is true or false.

Parameters:

point - point at which to calculate the normal and value (local coordinates)

clipToGrid - if true, return the nearest grid value if point is outside the grid volume

Returns:

interpolated value, or null

getRenderVector

public boolean getRenderVector(Vector3d vec3,
                               int xi,
                               int yj,
                               int zk)

Description copied from class: InterpolatingGridBase

For grid subclasses wishing to render 3D vector information, this method should be overridden to optionally returns a vector quantity associated with the vertex at indices xi, yj, and zk. Should returns null if no vector information should be rendered at that vertex.

Overrides:

getRenderVector in class InterpolatingGridBase

Parameters:

vec3 - three vector value

xi - x vertex index

yj - y vertex index

zk - z vertex index

Returns:

true if the vector quantity maps to a 3-vector value

getRenderVectorScale

public double getRenderVectorScale()

Description copied from class: InterpolatingGridBase

For grid subclasses wishing to render 3D vector information, this method should be overridden to return a scaling factor to be applied to vectors returned by InterpolatingGridBase.getRenderVector(maspack.matrix.Vector3d, int, int, int) to determine the length of the actual rendered vector. Returning 0 disables vector rendering.

Overrides:

getRenderVectorScale in class InterpolatingGridBase

Returns:

scaling factor for rendered vectors

setRenderVectorScale

public void setRenderVectorScale(double scale)

epsilonEquals

public boolean epsilonEquals(VectorGrid<T> grid,
                             double tol)

Returns true if this grid equals another within a prescribed tolerance. The grids are equal if the resolution, widths, center, orientation and values are equal. Specifying tol = 0 requires exact equality.

Parameters:

grid - grid to compare against

tol - floating point tolerance (absolute)

scanValue

public T scanValue(ReaderTokenizer rtok)
            throws java.io.IOException

Scans and returns an instance of the vector type associated with this grid from a reader tokenizer. Returns null if the next token is the word "null".

Parameters:

rtok - tokenizer to read the value from

Returns:

parsed vector value, or null

Throws:

java.io.IOException

writeValue

public <S> void writeValue(java.io.PrintWriter pw,
                           NumberFormat fmt,
                           T val)
                    throws java.io.IOException

Writes a vector of the type associated with this grid to a PrintWriter. If the value is null, writes out the word "null".

Parameters:

pw - writer to write the value to

fmt - format for the floating point values

val - value to be written

Throws:

java.io.IOException