public Grid2D raytraceScene(PrioritizableScene phantomScene, Projection projection) { Trajectory geom = Configuration.getGlobalConfiguration().getGeometry(); // Grid2D slice = new Grid2D(geom.getDetectorWidth(), geom.getDetectorHeight()); Grid2D slice = detector.createDetectorGrid(geom.getDetectorWidth(), geom.getDetectorHeight(), projection); rayTracer.setScene(phantomScene); // Second rule of optimization is: Optimize later. PointND raySource = new PointND(0, 0, 0); raySource.setCoordinates(projection.computeCameraCenter()); StraightLine castLine = new StraightLine(raySource, new SimpleVector(0, 0, 0)); SimpleVector centerPixDir = null; if (accurate) { centerPixDir = projection.computePrincipalAxis(); } // SimpleVector prinpoint = trajectory.getProjectionMatrix(sliceNumber).getPrincipalPoint(); double xcorr = 0; // trajectory.getDetectorWidth()/2 - prinpoint.getElement(0); double ycorr = 0; // trajectory.getDetectorHeight()/2 - prinpoint.getElement(1); double length = trajectory.getSourceToDetectorDistance(); Edge environmentEdge = new Edge(new PointND(0), new PointND(length)); ArrayList<PhysicalObject> fallBackBackground = new ArrayList<PhysicalObject>(1); SimpleVector pixel = new SimpleVector(0, 0); boolean negate = false; for (int y = 0; y < trajectory.getDetectorHeight(); y++) { for (int x = 0; x < trajectory.getDetectorWidth(); x++) { pixel.setElementValue(0, x - xcorr); pixel.setElementValue(1, y - ycorr); SimpleVector dir = projection.computeRayDirection(pixel); if ((y == 0) && (x == 0)) { // Check that ray direction is towards origin. double max = 0; int index = 0; for (int i = 0; i < 3; i++) { if (Math.abs(dir.getElement(i)) > max) { max = Math.abs(dir.getElement(i)); index = i; } } double t = -raySource.get(index) / dir.getElement(index); if (t < 0) negate = true; } if (negate) dir.negate(); castLine.setDirection(dir); ArrayList<PhysicalObject> segments = rayTracer.castRay(castLine); if (accurate) { double dirCosine = SimpleOperators.multiplyInnerProd(centerPixDir, dir); length = trajectory.getSourceToDetectorDistance() / dirCosine; } if (segments == null) { fallBackBackground.clear(); segments = fallBackBackground; } else { if (accurate) { environmentEdge = new Edge(new PointND(0), new PointND(length - getTotalSegmentsLength(segments))); } } environment.setShape(environmentEdge); segments.add(environment); /* old code: double integral = absorptionModel.evaluateLineIntegral(segments); slice.putPixelValue(x, y, integral); */ detector.writeToDetector(slice, x, y, segments); } } return slice; }
public void setTrajectory( int numProjectionMatrices, double sourceToAxisDistance, double averageAngularIncrement, double detectorOffsetX, double detectorOffsetY, CameraAxisDirection uDirection, CameraAxisDirection vDirection, SimpleVector rotationAxis, PointND rotationCenter, double angleFirstProjection) { this.projectionMatrices = new Projection[numProjectionMatrices]; this.primaryAngles = new double[numProjectionMatrices]; this.numProjectionMatrices = numProjectionMatrices; this.sourceToAxisDistance = sourceToAxisDistance; this.averageAngularIncrement = averageAngularIncrement; this.detectorOffsetU = detectorOffsetX; this.detectorOffsetV = detectorOffsetY; double cosPhi = Math.cos(General.toRadians(angleFirstProjection)); double sinPhi = Math.sin(General.toRadians(angleFirstProjection)); SimpleMatrix rotMat = new SimpleMatrix(3, 3); rotMat.setElementValue(0, 0, cosPhi); rotMat.setElementValue(0, 1, sinPhi); rotMat.setElementValue(1, 0, -sinPhi); rotMat.setElementValue(1, 1, cosPhi); rotMat.setElementValue(2, 2, 1); SimpleVector centerToCameraIdealAtInitialAngle = SimpleOperators.multiply(rotMat, new SimpleVector(sourceToAxisDistance, 0, 0)); Plane3D trajPlane = new Plane3D( rotationAxis, SimpleOperators.multiplyInnerProd(rotationAxis, rotationCenter.getAbstractVector())); double distToPlane = trajPlane.computeDistance(new PointND(centerToCameraIdealAtInitialAngle)); SimpleVector centerToCameraDir = SimpleOperators.subtract( SimpleOperators.add( rotationAxis.multipliedBy(-1 * distToPlane), centerToCameraIdealAtInitialAngle), rotationCenter.getAbstractVector()); centerToCameraDir.divideBy(centerToCameraDir.normL2()); SimpleVector centerToCameraInitialInPlane = centerToCameraDir.multipliedBy(sourceToAxisDistance); for (int i = 0; i < numProjectionMatrices; i++) { primaryAngles[i] = i * averageAngularIncrement + angleFirstProjection; // System.out.println(primaryAngles[i] + " " + averageAngularIncrement + " " + // this.reconDimensions[0] + " " + this.reconDimensions[1]); projectionMatrices[i] = new Projection(); double rotationAngle = General.toRadians(primaryAngles[i]); projectionMatrices[i].setRtFromCircularTrajectory( rotationCenter.getAbstractVector(), rotationAxis, sourceToAxisDistance, centerToCameraInitialInPlane, uDirection, vDirection, rotationAngle); SimpleVector spacingUV = new SimpleVector(pixelDimensionX, pixelDimensionY); SimpleVector sizeUV = new SimpleVector(detectorWidth, detectorHeight); SimpleVector offset = new SimpleVector(detectorOffsetX, detectorOffsetY); projectionMatrices[i].setKFromDistancesSpacingsSizeOffset( sourceToDetectorDistance, spacingUV, sizeUV, offset, 1.0, 0); } this.projectionStackSize = numProjectionMatrices; // System.out.println("Defined geometry with SDD " +sourceToDetectorDistance); }