/// <summary>Calculates the intersection point between 3 planes</summary>
/// <param name="inPlane1">The first plane</param>
/// <param name="inPlane2">The second plane</param>
/// <param name="inPlane3">The third plane</param>
/// <returns>The intersection point between the 3 planes.The returned point will consist out NaN values when there is no intersection.</returns>
static public Vector3 Intersection(CSGPlane inPlane1,
CSGPlane inPlane2,
CSGPlane inPlane3)
{
try
{
var plane1a = (decimal)inPlane1.a;
var plane1b = (decimal)inPlane1.b;
var plane1c = (decimal)inPlane1.c;
var plane1d = (decimal)inPlane1.d;
var plane2a = (decimal)inPlane2.a;
var plane2b = (decimal)inPlane2.b;
var plane2c = (decimal)inPlane2.c;
var plane2d = (decimal)inPlane2.d;
var plane3a = (decimal)inPlane3.a;
var plane3b = (decimal)inPlane3.b;
var plane3c = (decimal)inPlane3.c;
var plane3d = (decimal)inPlane3.d;
var bc1 = (plane1b * plane3c) - (plane3b * plane1c);
var bc2 = (plane2b * plane1c) - (plane1b * plane2c);
var bc3 = (plane3b * plane2c) - (plane2b * plane3c);
var w = -((plane1a * bc3) + (plane2a * bc1) + (plane3a * bc2));
var ad1 = (plane1a * plane3d) - (plane3a * plane1d);
var ad2 = (plane2a * plane1d) - (plane1a * plane2d);
var ad3 = (plane3a * plane2d) - (plane2a * plane3d);
var x = -((plane1d * bc3) + (plane2d * bc1) + (plane3d * bc2));
var y = -((plane1c * ad3) + (plane2c * ad1) + (plane3c * ad2));
var z = +((plane1b * ad3) + (plane2b * ad1) + (plane3b * ad2));
x /= w;
y /= w;
z /= w;
var result = new Vector3((float)x, (float)y, (float)z);
if (float.IsNaN(result.x) || float.IsInfinity(result.x) ||
float.IsNaN(result.y) || float.IsInfinity(result.y) ||
float.IsNaN(result.z) || float.IsInfinity(result.z))
{
return(MathConstants.NaNVector3);
}
return(result);
}
catch
{
return(MathConstants.NaNVector3);
}
}
public bool Equals(CSGPlane other)
{
if (System.Object.ReferenceEquals(this, other))
{
return(true);
}
if (System.Object.ReferenceEquals(other, null))
{
return(false);
}
return(Mathf.Abs(this.Distance(other.pointOnPlane)) <= MathConstants.DistanceEpsilon &&
Mathf.Abs(other.Distance(this.pointOnPlane)) <= MathConstants.DistanceEpsilon &&
Mathf.Abs(a - other.a) <= MathConstants.NormalEpsilon &&
Mathf.Abs(b - other.b) <= MathConstants.NormalEpsilon &&
Mathf.Abs(c - other.c) <= MathConstants.NormalEpsilon);
}
