Package org.jlab.geom.prim

Class Triangle3D

java.lang.Object
org.jlab.geom.prim.Triangle3D
All Implemented Interfaces:
Face3D, Transformable, Showable
public final class Triangle3D extends Object implements Face3D
A 3D triangle represented by three points.

Since any three points in 3D space that are not collinear define a plane, a triangle can be converted into a plane via plane().

The normal of the surface of a triangle is oriented such that when looking antiparallel to the normal towards the triangle the triangle's points wound counterclockwise. Conversely, when looking in a direction parallel to the normal, the points are wound in a clockwise fashion.

The intersection of a line with a triangle can be calculated using the intersection methods: intersection(...), intersectionRay(...), intersectionSegment(...).

Author:
gavalian

  • Constructor Summary

    Constructors
    Constructor
    Description
    Triangle3D()
    Constructs a new Triangle3D with all three points at the origin.
    Triangle3D(double x0, double y0, double z0, double x1, double y1, double z1, double x2, double y2, double z2)
    Constructs a new Triangle3D with the points at the specified coordinates.
    Triangle3D(Point3D point0, Point3D point1, Point3D point2)
    Constructs a new Triangle3D from the given points.
    Triangle3D(Triangle3D triangle)
    Constructs a new Triangle3D with its points coinciding with the points of the given triangle.

  • Method Summary

    Modifier and Type
    Method
    Description
    Point3D
    center()
    Constructs a new Point3D at the geometric mean of the three points in this Triangle3D.
    void
    copy(Triangle3D triangle)
    Sets the points of this Triangle3D to coincide with points of the given triangle.
    double
    distanceFromEdge(Point3D p)
    Computes the minimum distance of the given point from the edges of this Triangle3D.
    int
    intersection(Line3D line, List<Point3D> intersections)
    Finds the intersections of the given infinite line with this Face3D.
    int
    intersectionRay(Line3D line, List<Point3D> intersections)
    Finds the intersections of the given ray with this Face3D.
    int
    intersectionSegment(Line3D line, List<Point3D> intersections)
    Finds the intersections of the given line segment with this Face3D.
    boolean
    isInside(Point3D p)
    Test whether the given point is inside the area of this Triangle3D.
    Vector3D
    normal()
    Constructs the unit vector normal to the plane of this Triangle3D.
    Plane3D
    plane()
    Constructs the the plane of this Triangle3D.
    Point3D
    point(int index)
    Returns the point from this Face3D with corresponding index.
    void
    rotateX(double angle)
    Rotates this object clockwise around the x axis.
    void
    rotateY(double angle)
    Rotates this object clockwise around the y axis.
    void
    rotateZ(double angle)
    Rotates this object clockwise around the z axis.
    void
    set(double x0, double y0, double z0, double x1, double y1, double z1, double x2, double y2, double z2)
    Sets the points of the triangle to coincide with the given coordinates.
    void
    set(Point3D point0, Point3D point1, Point3D point2)
    Sets the points of this Triangle3D to coincide with the given points.
    void
    show()
    Invokes System.out.println(this).
    String
    toString()
     
    void
    translateXYZ(double x, double y, double z)
    Translates this object linearly by the amounts specified.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Triangle3D

      public Triangle3D()
      Constructs a new Triangle3D with all three points at the origin.

    • Triangle3D

      public Triangle3D(double x0, double y0, double z0, double x1, double y1, double z1, double x2, double y2, double z2)
      Constructs a new Triangle3D with the points at the specified coordinates.
      Parameters:
      x0 - x coordinate of the first point
      y0 - y coordinate of the first point
      z0 - z coordinate of the first point
      x1 - x coordinate of the second point
      y1 - y coordinate of the second point
      z1 - z coordinate of the second point
      x2 - x coordinate of the third point
      y2 - y coordinate of the third point
      z2 - z coordinate of the third point

    • Triangle3D

      public Triangle3D(Point3D point0, Point3D point1, Point3D point2)
      Constructs a new Triangle3D from the given points.
      Parameters:
      point0 - the first point
      point1 - the second point
      point2 - the third point

    • Triangle3D

      public Triangle3D(Triangle3D triangle)
      Constructs a new Triangle3D with its points coinciding with the points of the given triangle.
      Parameters:
      triangle - the triangle to copy

  • Method Details

    • copy

      public void copy(Triangle3D triangle)
      Sets the points of this Triangle3D to coincide with points of the given triangle.
      Parameters:
      triangle - the triangle to copy

    • set

      public void set(double x0, double y0, double z0, double x1, double y1, double z1, double x2, double y2, double z2)
      Sets the points of the triangle to coincide with the given coordinates.
      Parameters:
      x0 - x coordinate of the first point
      y0 - y coordinate of the first point
      z0 - z coordinate of the first point
      x1 - x coordinate of the second point
      y1 - y coordinate of the second point
      z1 - z coordinate of the second point
      x2 - x coordinate of the third point
      y2 - y coordinate of the third point
      z2 - z coordinate of the third point

    • set

      public void set(Point3D point0, Point3D point1, Point3D point2)
      Sets the points of this Triangle3D to coincide with the given points.
      Parameters:
      point0 - the first point
      point1 - the second point
      point2 - the third point

    • point

      public Point3D point(int index)
      Description copied from interface: Face3D
      Returns the point from this Face3D with corresponding index. If an invalid index is given, then null is returned.
      Specified by:
      point in interface Face3D
      Parameters:
      index - index of the point
      Returns:
      the point at the corresponding index, otherwise null

    • center

      public Point3D center()
      Constructs a new Point3D at the geometric mean of the three points in this Triangle3D.
      Returns:
      the center of this Triangle3D

    • normal

      public Vector3D normal()
      Constructs the unit vector normal to the plane of this Triangle3D.
      Returns:
      the normal to the plane of this Triangle3D

    • plane

      public Plane3D plane()
      Constructs the the plane of this Triangle3D.
      Returns:
      the plane of this Triangle3D

    • isInside

      public boolean isInside(Point3D p)
      Test whether the given point is inside the area of this Triangle3D.
      Parameters:
      p - the given point
      Returns:
      true if inside or false if outside

    • distanceFromEdge

      public double distanceFromEdge(Point3D p)
      Computes the minimum distance of the given point from the edges of this Triangle3D.
      Parameters:
      p - the given point
      Returns:
      the signed distance to the Triangle3D edges, positive if inside or negative if outside

    • intersection

      public int intersection(Line3D line, List<Point3D> intersections)
      Description copied from interface: Face3D
      Finds the intersections of the given infinite line with this Face3D. If intersections are found they will be appended to the given list. The return value will indicate the number of intersections that were found.
      Specified by:
      intersection in interface Face3D
      Parameters:
      line - the infinite line
      intersections - the list to store the intersections in
      Returns:
      the number of intersections found

    • intersectionRay

      public int intersectionRay(Line3D line, List<Point3D> intersections)
      Description copied from interface: Face3D
      Finds the intersections of the given ray with this Face3D. If intersections are found they will be appended to the given list. The return value will indicate the number of intersections that were found.
      Specified by:
      intersectionRay in interface Face3D
      Parameters:
      line - the ray
      intersections - the list to store the intersections in
      Returns:
      the number of intersections found

    • intersectionSegment

      public int intersectionSegment(Line3D line, List<Point3D> intersections)
      Description copied from interface: Face3D
      Finds the intersections of the given line segment with this Face3D. If intersections are found they will be appended to the given list. The return value will indicate the number of intersections that were found.
      Specified by:
      intersectionSegment in interface Face3D
      Parameters:
      line - the line segment
      intersections - the list to store the intersections in
      Returns:
      the number of intersections found

    • translateXYZ

      public void translateXYZ(double x, double y, double z)
      Description copied from interface: Transformable
      Translates this object linearly by the amounts specified.
      Specified by:
      translateXYZ in interface Transformable
      Parameters:
      x - amount to translate along the x axis
      y - amount to translate along the y axis
      z - amount to translate along the z axis

    • rotateX

      public void rotateX(double angle)
      Description copied from interface: Transformable
      Rotates this object clockwise around the x axis.
      Specified by:
      rotateX in interface Transformable
      Parameters:
      angle - rotation angle in radians

    • rotateY

      public void rotateY(double angle)
      Description copied from interface: Transformable
      Rotates this object clockwise around the y axis.
      Specified by:
      rotateY in interface Transformable
      Parameters:
      angle - rotation angle in radians

    • rotateZ

      public void rotateZ(double angle)
      Description copied from interface: Transformable
      Rotates this object clockwise around the z axis.
      Specified by:
      rotateZ in interface Transformable
      Parameters:
      angle - rotation angle in radians

    • show

      public void show()
      Invokes System.out.println(this).
      Specified by:
      show in interface Showable

    • toString

      public String toString()
      Overrides:
      toString in class Object