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;
  }
Exemplo n.º 2
0
  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);
  }