jvx.numeric
Class PnLIC

java.lang.Object
  |
  +--jvx.numeric.PnLIC

public class PnLIC

extends java.lang.Object

Line Integral Convolution for vector field visualization.

Version:

09.03.00, 1.06 revised (ep) bug-fixes.
20.02.00, 1.05 revised (ep) corrected "integralh-bug".
04.01.00, 1.04 revised (ep)
22.12.99, 1.03 revised (ep)
11.12.99, 1.02 revised (ep) adaptive kernelwidth

Field Summary

protected double	m_coarseness Control of the noise.
protected PgElementSet	m_geom the geometry
protected int	m_height Height of the texture in pixels.
protected double	m_integralh Stepsize of the integration method.
protected int	m_kernelwidth Normal width of the convolution kernel.
protected int	m_maxhits After the m_maxhits'th time the streamline hits a pixel that was hit by other lines more than m_maxhits times, the convolution of this streamline stops.
protected int	m_minKernel Kernelwidth for velocity near zero.
protected PnNoise	m_noise Procedural noise.
protected int[]	m_pix Texture pixel array.
protected PnGeodesicRK	m_rk Runge-kutta class.
protected double	m_steplen Step from one pixel to the next.
protected PdVector[][]	m_texCoords Texture coordinates buffer.
protected int	m_width Width of the texture in pixels.

Constructor Summary

PnLIC(PgElementSet geom, int size, double time, PnGeodesicRK rk)
Creates a new LIC processor.

Method Summary

protected int	getOutline(PdVector[] elemTex, int width, int height, PiVector xc, PiVector yc) Calculates outline of triangle texture coordinates in texture pixels by line scanning.
void	getPixArray(int[] pix) Puts actual LIC texture line by line into alphaRGB pixel array.
void	makeElement(int elemIndex) Computes Line Integral Convolution texture along all integral lines that begin within given element.
void	makeLIC() Computes LIC texture for all elements of geometry.
boolean	setCoarseness(double coarse) Sets the coarseness of noise.
boolean	setConvolutionWidth(int numPixels) Sets normal (one-velocity) convolution width along integral lines.
boolean	setMinConvolutionWidth(int numPixels)
void	setStepSize(double h) Sets the stepsize of the runge-kutta integration method.
protected double	triangleElemTexCoords(PgElementSet geom) Calculates element texture coordinates for triangulation.

Methods inherited from class java.lang.Object

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

Field Detail

m_geom

protected PgElementSet m_geom

the geometry

m_maxhits

protected int m_maxhits

After the m_maxhits'th time the streamline hits a pixel that was hit by other lines more than m_maxhits times, the convolution of this streamline stops.

m_rk

protected PnGeodesicRK m_rk

Runge-kutta class.

m_integralh

protected double m_integralh

Stepsize of the integration method.

m_width

protected int m_width

Width of the texture in pixels.

m_height

protected int m_height

Height of the texture in pixels.

m_pix

protected int[] m_pix

Texture pixel array.

m_texCoords

protected PdVector[][] m_texCoords

Texture coordinates buffer.

m_steplen

protected double m_steplen

Step from one pixel to the next.

m_kernelwidth

protected int m_kernelwidth

Normal width of the convolution kernel.

m_minKernel

protected int m_minKernel

Kernelwidth for velocity near zero.

m_coarseness

protected double m_coarseness

Control of the noise.

m_noise

protected PnNoise m_noise

Procedural noise.

Constructor Detail

PnLIC

public PnLIC(PgElementSet geom,
             int size,
             double time,
             PnGeodesicRK rk)

Creates a new LIC processor.

Parameters:

geom - underlying geometry

size - width and height of the LIC-texture

time - not yet implemented

rk - geodesic runge-kutta method that contains the vector field that shall be visualized

See Also:

PnGeodesicRK

Method Detail

setCoarseness

public boolean setCoarseness(double coarse)

Sets the coarseness of noise.

Parameters:

coarse - ==0. fine; ==1. constant

setConvolutionWidth

public boolean setConvolutionWidth(int numPixels)

Sets normal (one-velocity) convolution width along integral lines.

Parameters:

numPixels - new width given in texture pixels

setMinConvolutionWidth

public boolean setMinConvolutionWidth(int numPixels)

setStepSize

public void setStepSize(double h)

Sets the stepsize of the runge-kutta integration method.

Parameters:

h - stepsize

makeElement

public void makeElement(int elemIndex)

Computes Line Integral Convolution texture along all integral lines that begin within given element. These integral lines may leave the element.

Parameters:

elemIndex - global element index in underlying geometry

getPixArray

public void getPixArray(int[] pix)

Puts actual LIC texture line by line into alphaRGB pixel array.

Parameters:

pix - output: actual LIC texture; should be of size LICSIZE*LICSIZE

makeLIC

public void makeLIC()

Computes LIC texture for all elements of geometry. Method getPixArray returns the texture image.

See Also:

getPixArray(int[])

triangleElemTexCoords

protected double triangleElemTexCoords(PgElementSet geom)

Calculates element texture coordinates for triangulation. Puts triangles in lines with longest edges at top.

Parameters:

geom - triangulation

Returns:

the scaling factor from worldcoords to texturecoords

getOutline

protected int getOutline(PdVector[] elemTex,
                         int width,
                         int height,
                         PiVector xc,
                         PiVector yc)

Calculates outline of triangle texture coordinates in texture pixels by line scanning. Line number j has points (xc[j],yc[j]), (xc[length-1-j],yc[j]).

Parameters:

elemTex - normalized texture coordinates of triangle

width - width of the texture image (pixel)

height - height of the texture image (pixel)

xc - output: x-coordinates of outline

yc - output: y-coordinates of outline

Returns:

length of coordinate arrays