maspack.geometry

Class ScalarGrid

java.lang.Object

maspack.geometry.InterpolatingGridBase

maspack.geometry.ScalarGridBase

maspack.geometry.ScalarGrid

All Implemented Interfaces:

HasRenderProps, IsRenderable, IsSelectable, Renderable, Scannable

public class ScalarGrid
extends ScalarGridBase

Implements a regular 3D grid that interpolates scalar values using trilinear interpolation.

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.

Scalar 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 the special value ScalarGridBase.OUTSIDE_GRID is returned.

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

Field Summary

Fields inherited from class maspack.geometry.ScalarGridBase

OUTSIDE_GRID

Fields inherited from interface maspack.render.IsRenderable

TRANSPARENT, TWO_DIMENSIONAL

Constructor Summary

Constructors

Constructor and Description
ScalarGrid() Default constructor.
ScalarGrid(ScalarGrid grid) Creates a new grid that is a copy of an existing grid.
ScalarGrid(Vector3d widths, Vector3i resolution) Creates a new grid with specified widths and resolution, centered on the local coordinate system.
ScalarGrid(Vector3d widths, Vector3i resolution, RigidTransform3d TCL) Creates a new grid with specified widths, resolution, and position and orientation of the center given by TCL.
ScalarGrid(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.

Method Summary

Modifier and Type	Method and Description
boolean	epsilonEquals(ScalarGrid grid, double tol)
double	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.
double	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.
double	getVertexValue(int vi) Queries the value for the vertex indexed by vi.
double	getVertexValue(int xi, int yj, int zk) Queries the value at a specified vertex, as specified by x, y, z indices.
double	getVertexValue(Vector3i vxyz) Queries the value at a specified vertex, as specified by x, y, z indices.
double[]	getVertexValues() Returns an array of the values at each vertex.
double	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.
double	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.
void	set(ScalarGrid grid)
void	setVertexValue(int vi, double value) Sets the value for the vertex indexed by vi.
void	setVertexValue(int xi, int yi, int zi, double value) Sets the value for the vertex indexed by its x, y, z indices.
void	setVertexValues(double[] values) Sets all the vertex values for this grid.
void	zeroVertexValues() Zeros all the vertex values for this grid.

Methods inherited from class maspack.geometry.ScalarGridBase

createDistanceSurface, createDistanceSurface, createDistanceSurface, epsilonEquals, getParameterType

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, getRenderVector, getRenderVectorScale, 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

ScalarGrid

public ScalarGrid()

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

ScalarGrid

public ScalarGrid(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:

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

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

ScalarGrid

public ScalarGrid(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:

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.

ScalarGrid

public ScalarGrid(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:

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

ScalarGrid

public ScalarGrid(ScalarGrid grid)

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

Parameters:

grid - grid to copy

Method Detail

set

public void set(ScalarGrid grid)

setVertexValues

public void setVertexValues(double[] 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.

Parameters:

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

getVertexValues

public double[] getVertexValues()

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

Returns:

array of vertex values.

setVertexValue

public void setVertexValue(int vi,
                           double value)

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

Parameters:

vi - vertex index

value - vertex value

setVertexValue

public void setVertexValue(int xi,
                           int yi,
                           int zi,
                           double value)

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

Overrides:

setVertexValue in class ScalarGridBase

Parameters:

xi - x vertex index

yi - y vertex index

zi - z vertex index

value - new value for the vertex

getVertexValue

public double getVertexValue(int vi)

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

Parameters:

vi - vertex index

Returns:

value at the vertex

getVertexValue

public double getVertexValue(Vector3i vxyz)

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

Parameters:

vxyz - x, y, z vertex indices

Returns:

value at the vertex

getVertexValue

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

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

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 double 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, ScalarGridBase.OUTSIDE_GRID is returned.

Parameters:

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

Returns:

interpolated value, or OUTSIDE_GRID

getWorldValue

public double 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 ScalarGridBase.OUTSIDE_GRID, 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 OUTSIDE_GRID

getLocalValue

public double 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, ScalarGridBase.OUTSIDE_GRID is returned.

Parameters:

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

Returns:

interpolated value, or OUTSIDE_GRID

getLocalValue

public double 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 ScalarGridBase.OUTSIDE_GRID, 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 OUTSIDE_GRID

epsilonEquals

public boolean epsilonEquals(ScalarGrid grid,
                             double tol)