java.lang.Object
- gov.nih.mipav.view.renderer.J3D.volumeview.Renderer
- - gov.nih.mipav.view.renderer.J3D.volumeview.RayCastRenderer

Direct Known Subclasses:

RayCastColor, RayCastIntensity
```
public abstract class RayCastRenderer
extends Renderer
```
A ray tracer for 3D images. Either a parallel or perspective camera model can be selected to form the rays. In the parallel case, zooming is accomplished by changing the size of the viewport. In the perspective case, zooming is accomplished by moving the eye point. The line segment of intersection (if it exists) of a ray with the bounding box of the image is computed. The image is trilinearly interpolated to allow subvoxel evaluations.
The camera coordinate system has eye point is E = (0,0,z). The direction vector is D = (0,0,1), the up vector is U = (0,1,0), and the right vector is R = (1,0,0). Only the eye point is allowed to change. Since the 3D image can be arbitrarily rotated (via a virtual trackball), any portion of the image can be viewed either close up or far away.

The view plane has normal D and origin at E+n*D (n=near). The view frustum is orthogonal and has no far plane. For a perspective camera, the field of view is given as an angle A subtended at the eye point. In camera coordinates, the view port is the square [-e,e]^2 where e = n*tan(A/2). In world coordinates, the corners of the square are E+n*D+s*e*U+t*e*R where |s| = |t| = 1 (four choices on sign). For a parallel camera, there is no field of view.

The mapping between the viewport [-e,e]^2 and the B-by-B render image is the following. If (i,j) is a pixel in the image, then the corresponding viewport point is (r,u) = (-e+2*e*i/(B-1),-e+2*e*j/(B-1)).

Field Summary

Fields
Modifier and Type	Field	Description
`protected float`	`blue`	DOCUMENT ME!
`private boolean`	`bluring`	Blur the final image to reduce voxel contrast.
`(package private) float`	`clipRegionXNeg`	The clip plane position in the box.
`(package private) float`	`clipRegionXPos`	The clip plane position in the box.
`(package private) float`	`clipRegionYNeg`	DOCUMENT ME!
`(package private) float`	`clipRegionYPos`	DOCUMENT ME!
`(package private) float`	`clipRegionZNeg`	DOCUMENT ME!
`(package private) float`	`clipRegionZPos`	DOCUMENT ME!
`(package private) float`	`fXDelta`	x, y, z delta value.
`(package private) float`	`fYDelta`	x, y, z delta value.
`(package private) float`	`fZDelta`	x, y, z delta value.
`protected float`	`green`	DOCUMENT ME!
`protected float`	`m_fInvXDelta`	The inverse delta values are for scaling back to original coordinates for correct interpolation of the image.
`protected float`	`m_fInvYDelta`	The inverse delta values are for scaling back to original coordinates for correct interpolation of the image.
`protected float`	`m_fInvZDelta`	The inverse delta values are for scaling back to original coordinates for correct interpolation of the image.
`private float`	`m_fT0`	the parameters for clipped rays.
`private float`	`m_fT1`	the parameters for clipped rays.
`protected javax.vecmath.Vector3f`	`m_kExtent`	Oriented bounding box of image, centered at (0,0,0), axes are stored as the columns of a rotation matrix, and half-widths are specified.
`protected javax.vecmath.Vector3f`	`m_kMDir`	DOCUMENT ME!
`protected javax.vecmath.Point3f`	`m_kMOrig`	Ray in box (model) coordinates.
`protected javax.vecmath.Point3f`	`m_kP0`	the intersection points of ray with box.
`protected javax.vecmath.Point3f`	`m_kP1`	the intersection points of ray with box.
`protected javax.vecmath.Vector3f`	`m_kPDiff`	DOCUMENT ME!
`protected javax.vecmath.Vector3f`	`m_kV`	Intersection of ray with view plane.
`protected javax.vecmath.Vector3f`	`m_kWDir`	DOCUMENT ME!
`protected javax.vecmath.Vector3f`	`m_kWOrig`	Ray in world coordinates.
`private boolean`	`multiThreadingEnabled`
`private int`	`nthreads`
`protected ModelLUT`	`opacityFunctA`	DOCUMENT ME!
`protected ModelLUT`	`opacityFunctB`	DOCUMENT ME!
`protected float`	`red`	DOCUMENT ME!
`private int[]`	`tempImage`	DOCUMENT ME!
`protected javax.vecmath.Color3f`	`vertexDiffuse`	Vertex material diffuse color.
`protected javax.vecmath.Color3f`	`vertexSpecular`	Vertex material specular color.
`protected float[]`	`xLUTa`	Used to store the transfer function points for remapping to the LUT.
`protected float[]`	`xLUTb`	DOCUMENT ME!
`protected float[]`	`yLUTa`	DOCUMENT ME!
`protected float[]`	`yLUTb`	DOCUMENT ME!

Fields inherited from class gov.nih.mipav.view.renderer.J3D.volumeview.Renderer
m_aiRImage, m_akAxis, m_akNormal, m_bParallel, m_bReloadInput, m_fAngle, m_fExtreme, m_fFMult, m_fGamma, m_fNear, m_fRScaleX, m_fRScaleY, m_fXTrn, m_fYTrn, m_fZoom, m_iMaxBound, m_iMinBound, m_iRBound, m_iXBound, m_iXBoundM1, m_iXBoundM2, m_iXYProduct, m_iXYZProduct, m_iYBound, m_iYBoundM1, m_iYBoundM2, m_iZBound, m_iZBoundM1, m_iZBoundM2, m_kBackgroundColor, m_kEyeModel, m_kEyeWorld, m_kImage, m_kLightSet, m_kMaterial, m_kRotate

Constructor Summary

Constructors
Modifier	Constructor	Description
`protected`	`RayCastRenderer(ModelImage kImage, int iRBound, int[] aiRImage)`	The constructor for the ray tracer.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`private boolean`	`clipped(float fDen, float fNum, float[] t)`	Support for clipping line segments against coordinate planes.
`void`	`disposeLocal(boolean flag)`	Clean memory.
`protected void`	`finalize()`	Calls dispose.
`javax.vecmath.Vector3f`	`getAxis(int i)`	Read the current axis at index i.
`protected int`	`interpolate(javax.vecmath.Point3f kP, byte[] acImage)`	Trilinear interpolation of the image to produce image values at points P that are not at the integer voxel locations.
`private boolean`	`intersectsBox(javax.vecmath.Vector3f mDir, javax.vecmath.Point3f mOrig, javax.vecmath.Point3f p0, javax.vecmath.Point3f p1)`	Clip the current ray against the oriented bounding box of the 3D image.
`protected abstract void`	`processRay(int iIndex, int rayTraceStepSize)`	Process a ray that has intersected the oriented bounding box of the 3D image.
`protected abstract void`	`processRay(javax.vecmath.Point3f p0, javax.vecmath.Point3f p1, int iIndex, int rayTraceStepSize)`	Process a ray that has intersected the oriented bounding box of the 3D image.
`void`	`rotateBy(javax.vecmath.AxisAngle4f kAxisAngle)`	Rotate the oriented bounding box of the 3D image about the specified axis with the specified angle.
`void`	`rotateFrameBy(javax.media.j3d.Transform3D transform)`	Rotate the oriented bounding box of the 3D image about the specified axis with the specified angle.
`void`	`setAxis(int i, javax.vecmath.Vector3f kAxis)`	Change an axis of the oriented bounding box of the 3D image.
`void`	`setBlurFlag(boolean flag)`	Blur the resulting image or not.
`void`	`setDiffuse(java.awt.Color color)`	Set vertex material diffuse color.
`void`	`setOpacityFunctions(ModelLUT opacityFunctionA, ModelLUT opacityFunctionB)`	Add here.
`void`	`setSpecular(java.awt.Color color)`	Set vertex material specular color.
`void`	`setXBoundNeg(float value)`	Setup the X Negative clipping plane position.
`void`	`setXBoundPos(float value)`	Setup the X positive clipping plane position.
`void`	`setYBoundNeg(float value)`	Setup the Y Negative clipping plane position.
`void`	`setYBoundPos(float value)`	Setup the Y positive clipping plane position.
`void`	`setZBoundNeg(float value)`	Setup the Z negative clipping plane position.
`void`	`setZBoundPos(float value)`	Setup the Z positive clipping plane position.
`void`	`trace(int rayTraceStepSize, int iSpacing)`	Ray trace the 3D image in its current orientation as determined by the oriented bounding box.
`void`	`traceBlockRays(int xStart, int xEnd, int yStart, int yEnd, int rayTraceStepSize, int iSpacing)`

Methods inherited from class gov.nih.mipav.view.renderer.J3D.volumeview.Renderer
computeIntegralNormalizationFactor, convertWorldToModel, disposeLocal, getAngle, getBackgroundColor, getExtreme, getEyeDist, getEyePoint, getGamma, getMaxBound, getMinBound, getNear, getParallel, getXBound, getXTranslate, getYBound, getYTranslate, getZBound, getZoom, hasInputData, hasNormals, orthonormalize, reloadInputData, reloadInputData, setAngle, setBackgroundColor, setExtreme, setEyeDist, setGamma, setLighting, setMaterialShininess, setNear, setNearAndAngle, setNormals, setParallel, setXTranslate, setYTranslate, setZoom, traceInit, usesNormals

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - m_fInvXDelta
```
protected float m_fInvXDelta
```
    The inverse delta values are for scaling back to original coordinates for correct interpolation of the image.
  - m_fInvYDelta
```
protected float m_fInvYDelta
```
    The inverse delta values are for scaling back to original coordinates for correct interpolation of the image.
  - m_fInvZDelta
```
protected float m_fInvZDelta
```
    The inverse delta values are for scaling back to original coordinates for correct interpolation of the image.
  - m_kExtent
```
protected javax.vecmath.Vector3f m_kExtent
```
    Oriented bounding box of image, centered at (0,0,0), axes are stored as the columns of a rotation matrix, and half-widths are specified.
  - m_kMDir
```
protected javax.vecmath.Vector3f m_kMDir
```
    DOCUMENT ME!
  - m_kMOrig
```
protected javax.vecmath.Point3f m_kMOrig
```
    Ray in box (model) coordinates.
  - m_kP0
```
protected javax.vecmath.Point3f m_kP0
```
    the intersection points of ray with box.
  - m_kP1
```
protected javax.vecmath.Point3f m_kP1
```
    the intersection points of ray with box.
  - m_kPDiff
```
protected javax.vecmath.Vector3f m_kPDiff
```
    DOCUMENT ME!
  - m_kV
```
protected javax.vecmath.Vector3f m_kV
```
    Intersection of ray with view plane.
  - m_kWDir
```
protected javax.vecmath.Vector3f m_kWDir
```
    DOCUMENT ME!
  - m_kWOrig
```
protected javax.vecmath.Vector3f m_kWOrig
```
    Ray in world coordinates.
  - opacityFunctA
```
protected ModelLUT opacityFunctA
```
    DOCUMENT ME!
  - opacityFunctB
```
protected ModelLUT opacityFunctB
```
    DOCUMENT ME!
  - red
```
protected float red
```
    DOCUMENT ME!
  - green
```
protected float green
```
    DOCUMENT ME!
  - blue
```
protected float blue
```
    DOCUMENT ME!
  - vertexDiffuse
```
protected javax.vecmath.Color3f vertexDiffuse
```
    Vertex material diffuse color.
  - vertexSpecular
```
protected javax.vecmath.Color3f vertexSpecular
```
    Vertex material specular color.
  - xLUTa
```
protected float[] xLUTa
```
    Used to store the transfer function points for remapping to the LUT.
  - xLUTb
```
protected float[] xLUTb
```
    DOCUMENT ME!
  - yLUTa
```
protected float[] yLUTa
```
    DOCUMENT ME!
  - yLUTb
```
protected float[] yLUTb
```
    DOCUMENT ME!
  - clipRegionXNeg
```
float clipRegionXNeg
```
    The clip plane position in the box.
  - clipRegionXPos
```
float clipRegionXPos
```
    The clip plane position in the box.
  - clipRegionYNeg
```
float clipRegionYNeg
```
    DOCUMENT ME!
  - clipRegionYPos
```
float clipRegionYPos
```
    DOCUMENT ME!
  - clipRegionZNeg
```
float clipRegionZNeg
```
    DOCUMENT ME!
  - clipRegionZPos
```
float clipRegionZPos
```
    DOCUMENT ME!
  - fXDelta
```
float fXDelta
```
    x, y, z delta value.
  - fYDelta
```
float fYDelta
```
    x, y, z delta value.
  - fZDelta
```
float fZDelta
```
    x, y, z delta value.
  - bluring
```
private boolean bluring
```
    Blur the final image to reduce voxel contrast.
  - m_fT0
```
private float m_fT0
```
    the parameters for clipped rays.
  - m_fT1
```
private float m_fT1
```
    the parameters for clipped rays.
  - tempImage
```
private final int[] tempImage
```
    DOCUMENT ME!
  - multiThreadingEnabled
```
private final boolean multiThreadingEnabled
```
  - nthreads
```
private final int nthreads
```
- Constructor Detail
  - RayCastRenderer
```
protected RayCastRenderer(ModelImage kImage,
                          int iRBound,
                          int[] aiRImage)
```
    The constructor for the ray tracer. Currently, the only client of this class is VolumeRenderer.
    
    Parameters:
    
    kImage - the 3D image
    
    iRBound - the dimension of the square 2D renderer image
    
    aiRImage - The rendered image data stored in row-major order. Each integer pixel represents an RGB color in the format B | (G
- Method Detail
  - disposeLocal
```
public void disposeLocal(boolean flag)
```
    Clean memory.
    
    Parameters:
    
    flag - is true call the super.disposeLocal
  - getAxis
```
public javax.vecmath.Vector3f getAxis(int i)
```
    Read the current axis at index i.
    
    Specified by:
    
    getAxis in class Renderer
    
    Parameters:
    
    i - the axis index (0, 1, or 2)
    
    Returns:
    
    the current axis vector at index i
  - rotateBy
```
public void rotateBy(javax.vecmath.AxisAngle4f kAxisAngle)
```
    Rotate the oriented bounding box of the 3D image about the specified axis with the specified angle.
    
    Specified by:
    
    rotateBy in class Renderer
    
    Parameters:
    
    kAxisAngle - the axis and angle formulation for the rotation
  - rotateFrameBy
```
public void rotateFrameBy(javax.media.j3d.Transform3D transform)
```
    Rotate the oriented bounding box of the 3D image about the specified axis with the specified angle.
    
    Specified by:
    
    rotateFrameBy in class Renderer
    
    Parameters:
    
    transform - the axis and angle formulation for the rotation
  - setAxis
```
public void setAxis(int i,
                    javax.vecmath.Vector3f kAxis)
```
    Change an axis of the oriented bounding box of the 3D image.
    
    Parameters:
    
    i - the axis index (0, 1, or 2)
    
    kAxis - the new axis vector at index i
  - setBlurFlag
```
public void setBlurFlag(boolean flag)
```
    Blur the resulting image or not.
    
    Parameters:
    
    flag - true blur the image, false not blur.
  - setDiffuse
```
public void setDiffuse(java.awt.Color color)
```
    Set vertex material diffuse color.
    
    Parameters:
    
    color - true blur the image, false not blur.
  - setOpacityFunctions
```
public void setOpacityFunctions(ModelLUT opacityFunctionA,
                                ModelLUT opacityFunctionB)
```
    Add here.
    
    Parameters:
    
    opacityFunctionA - DOCUMENT ME!
    
    opacityFunctionB - DOCUMENT ME!
  - setSpecular
```
public void setSpecular(java.awt.Color color)
```
    Set vertex material specular color.
    
    Parameters:
    
    color - true blur the image, false not blur.
  - setXBoundNeg
```
public void setXBoundNeg(float value)
```
    Setup the X Negative clipping plane position.
    
    Specified by:
    
    setXBoundNeg in class Renderer
    
    Parameters:
    
    value - position of the X negative clip slider.
  - setXBoundPos
```
public void setXBoundPos(float value)
```
    Setup the X positive clipping plane position.
    
    Specified by:
    
    setXBoundPos in class Renderer
    
    Parameters:
    
    value - position of the X positive clip slider.
  - setYBoundNeg
```
public void setYBoundNeg(float value)
```
    Setup the Y Negative clipping plane position.
    
    Specified by:
    
    setYBoundNeg in class Renderer
    
    Parameters:
    
    value - position of the Y negative clip slider.
  - setYBoundPos
```
public void setYBoundPos(float value)
```
    Setup the Y positive clipping plane position.
    
    Specified by:
    
    setYBoundPos in class Renderer
    
    Parameters:
    
    value - positin of the Y positve clip slider.
  - setZBoundNeg
```
public void setZBoundNeg(float value)
```
    Setup the Z negative clipping plane position.
    
    Specified by:
    
    setZBoundNeg in class Renderer
    
    Parameters:
    
    value - position of the Z negative clip slider.
  - setZBoundPos
```
public void setZBoundPos(float value)
```
    Setup the Z positive clipping plane position.
    
    Specified by:
    
    setZBoundPos in class Renderer
    
    Parameters:
    
    value - position of the Z positive clip slider.
  - trace
```
public final void trace(int rayTraceStepSize,
                        int iSpacing)
```
    Ray trace the 3D image in its current orientation as determined by the oriented bounding box. The rendered image is initialized to the background color. A pixel is overwritten only when a ray intersects the bounding box of the image, that pixel corresponding to the given ray.
    
    Parameters:
    
    rayTraceStepSize - DOCUMENT ME!
    
    iSpacing - A positive value indicating how often to sample the rendered image. The typical value is 1 indicating that all rays corresponding to all pixels should be processed. If the value is 2, rays corresponding to pixels (x,y) with (x mod 2) = 0 and (y mod 2) = 0 are processed. The other pixels are assigned values of the modulo 2 neighbor pixel. Similar reduced sampling occurs with larger values of iSpacing. VolumeRenderer sets the spacing to be 2 when the image is being rotated by the virtual track ball. Once the image is finished rotating, a final trace is made with a spacing of 1.
  - traceBlockRays
```
public void traceBlockRays(int xStart,
                           int xEnd,
                           int yStart,
                           int yEnd,
                           int rayTraceStepSize,
                           int iSpacing)
```
    Parameters:
    
    xStart -
    
    xEnd -
    
    yStart -
    
    yEnd -
    
    rayTraceStepSize -
    
    iSpacing -
  - processRay
```
protected abstract void processRay(int iIndex,
                                   int rayTraceStepSize)
```
    Process a ray that has intersected the oriented bounding box of the 3D image. The method is only called if there is a line segment of intersection. The 'intersectsBox' stores the end points of the line segment in the class members m_kP0 and m_kP1 in image coordinates.
    The function sets the color of the pixel corresponding to the processed ray. The RGB value is stored as an integer in the format B | (G
    
    Parameters:
    
    iIndex - index of the pixel corresponding to the processed ray
    
    rayTraceStepSize - DOCUMENT ME!
  - processRay
```
protected abstract void processRay(javax.vecmath.Point3f p0,
                                   javax.vecmath.Point3f p1,
                                   int iIndex,
                                   int rayTraceStepSize)
```
    Process a ray that has intersected the oriented bounding box of the 3D image. The method is only called if there is a line segment of intersection. The 'intersectsBox' stores the end points of the line segment in the class members P0 and P1 in image coordinates. The local P0 and p1 are used for the multi-theading rendering.
    The function sets the color of the pixel corresponding to the processed ray. The RGB value is stored as an integer in the format B | (G
    
    Parameters:
    
    p0 - Local starting point.
    
    p1 - Local ending point
    
    iIndex - index of the pixel corresponding to the processed ray
    
    rayTraceStepSize - raycast step size.
  - finalize
```
protected void finalize()
                 throws java.lang.Throwable
```
    Calls dispose.
    
    Overrides:
    
    finalize in class Renderer
    
    Throws:
    
    java.lang.Throwable - DOCUMENT ME!
  - interpolate
```
protected final int interpolate(javax.vecmath.Point3f kP,
                                byte[] acImage)
```
    Trilinear interpolation of the image to produce image values at points P that are not at the integer voxel locations.
    
    Parameters:
    
    kP - the spatial point to be assigned an interpolated value
    
    acImage - The array of byte values to be interpolated
    
    Returns:
    
    The interpolated value for the point. If kP is not within the bounding box of the image, a value of -1 is returned.
  - clipped
```
private boolean clipped(float fDen,
                        float fNum,
                        float[] t)
```
    Support for clipping line segments against coordinate planes. The function computes the line segment parameter corresponding to the intersection of the segment with a coordinate plane. However, the expensive division is performed only if in fact there is an intersection. The deferred division speeds up the ray tracing a lot since this method is called up to 6 times per ray.
    
    Parameters:
    
    fDen - the denominator of the line segment parameter of the intersection
    
    fNum - the numerator of the line segment parameter of the intersection
    
    t - [] t[0] for the line starting point intersection parameter, t[1] for the line ending point intersection parameter.
    
    Returns:
    
    true if the entire line segment is entirely clipped by the current plane (segment is "outside" the plane), false if the segment intersects the plane or is contained "inside" the plane.
  - intersectsBox
```
private boolean intersectsBox(javax.vecmath.Vector3f mDir,
                              javax.vecmath.Point3f mOrig,
                              javax.vecmath.Point3f p0,
                              javax.vecmath.Point3f p1)
```
    Clip the current ray against the oriented bounding box of the 3D image. The trace method sets up the ray in world coordinates. The intersector converts the ray to box coordinates so that the ray is clipped against an axis-aligned box.
    The end points of the intersecting line segment are stored in class members m_kP0 and m_kP1 as image coordinates. The bounding box is centered at the origin. The image coordinates are just a translation of box coordinates so that the center of the box becomes the center of the image. The class members m_fT0 and m_fT1 are the corresponding line segment parameters. They are class members only because Java does not support call-by-reference semantics. In another language, the parameters can be local and passed to 'clipped' with the potential to be changed by 'clipped'.
    
    Returns:
    
    true if and only if the ray intersects the box

Class RayCastRenderer

Field Summary

Fields inherited from class gov.nih.mipav.view.renderer.J3D.volumeview.Renderer

Constructor Summary

Method Summary

Methods inherited from class gov.nih.mipav.view.renderer.J3D.volumeview.Renderer

Methods inherited from class java.lang.Object

Field Detail

m_fInvXDelta

m_fInvYDelta

m_fInvZDelta

m_kExtent

m_kMDir

m_kMOrig

m_kP0

m_kP1

m_kPDiff

m_kV

m_kWDir

m_kWOrig

opacityFunctA

opacityFunctB

red

green

blue

vertexDiffuse

vertexSpecular

xLUTa

xLUTb

yLUTa

yLUTb

clipRegionXNeg

clipRegionXPos

clipRegionYNeg

clipRegionYPos

clipRegionZNeg

clipRegionZPos

fXDelta

fYDelta

fZDelta

bluring

m_fT0

m_fT1

tempImage

multiThreadingEnabled

nthreads

Constructor Detail

RayCastRenderer

Method Detail

disposeLocal

getAxis

rotateBy

rotateFrameBy

setAxis

setBlurFlag

setDiffuse

setOpacityFunctions

setSpecular

setXBoundNeg

setXBoundPos

setYBoundNeg

setYBoundPos

setZBoundNeg

setZBoundPos

trace

traceBlockRays

processRay

processRay

finalize

interpolate

clipped

intersectsBox