/// <summary>
/// Returns the aspect ratio of the tetrahedra defined by 4 given points.
/// This is defined as the longest edge / shortest altitude.
/// </summary>
/// <param name="points"></param>
/// <returns></returns>
public static double GetTetraAspect(Vec3d p0, Vec3d p1, Vec3d p2, Vec3d p3)
{
double minEdge = 0.0;
double maxAlt = double.PositiveInfinity;
Vec3d v0 = p1 - p0;
Vec3d v1 = p2 - p1;
Vec3d v2 = p3 - p2;
Vec3d v3 = p0 - p3;
Sub(v0, v1, v2);
Sub(v1, v2, v3);
Sub(v2, v3, v0);
Sub(v3, v0, v1);
return(Math.Sqrt(minEdge) / Math.Sqrt(maxAlt));
void Sub(Vec3d a, Vec3d b, Vec3d c)
{
minEdge = Math.Max(minEdge, a.SquareLength);
maxAlt = Math.Min(maxAlt, Vec3d.Project(c, Vec3d.Cross(a, b)).SquareLength);
}
}
/// <summary>
///
/// </summary>
/// <param name="point"></param>
/// <param name="origin"></param>
/// <param name="normal"></param>
/// <returns></returns>
public static Vec3d ProjectToPlane(Vec3d point, Vec3d origin, Vec3d normal)
{
return(point + Vec3d.Project(origin - point, normal));
}
/// <summary>
///
/// </summary>
/// <param name="point"></param>
/// <param name="origin"></param>
/// <param name="normal"></param>
/// <returns></returns>
public static Vec3d ReflectInPlane(Vec3d point, Vec3d origin, Vec3d normal)
{
return(point + Vec3d.Project(origin - point, normal) * 2.0);
}
