public Vector3 Intersection(StraightLine l)
{
if (Math.Abs(Vector3.ScalarMultiplication(l.DirVector, N)) > 0.0001)
{
double t = (-D - C * l.point.Z - B * l.point.Y - A * l.point.X) / Vector3.ScalarMultiplication(l.DirVector, N);
return(new Vector3((l.point.X + t * l.DirVector.X), (l.point.Y + t * l.DirVector.Y), (l.point.Z + t * l.DirVector.Z)));
}
else
{
return(new Vector3());
}
}
public static bool LineSegmentContainsPoint(Vector3 a, Vector3 b, Vector3 p)
{
return((
StraightLine.StraightLineContainsPoint(new StraightLine(a, b), p))
&&
(Math.Min(a.X, b.X) <= p.X && p.X <= Math.Max(a.X, b.X))
&&
(Math.Min(a.Y, b.Y) <= p.Y && p.Y <= Math.Max(a.Y, b.Y))
&&
(Math.Min(a.Z, b.Z) <= p.Z && p.Z <= Math.Max(a.Z, b.Z)));
}
public static bool StraightLineContainsPoint(StraightLine l, Vector3 a)
{
if (!a.IsEmpty())
{
return
(
Math.Abs((a.X - l.point.X) * l.DirVector.Y - (a.Y - l.point.Y) * l.DirVector.X) < 0.0001
&&
Math.Abs((a.Y - l.point.Y) * l.DirVector.Z - (a.Z - l.point.Z) * l.DirVector.Y) < 0.0001
&&
Math.Abs((a.X - l.point.X) * l.DirVector.Z - (a.Z - l.point.Z) * l.DirVector.X) < 0.0001
);
}
return(false);
}
public Vector3 Intersection(StraightLine l)//если знаем, что они в одной плоскости
{
if (Math.Abs(l.DirVector.X * DirVector.Y - l.DirVector.Y * DirVector.X) < 0.0001 ||
Math.Abs(l.DirVector.Z * DirVector.Y - l.DirVector.Y * DirVector.Z) < 0.0001 ||
Math.Abs(l.DirVector.X * DirVector.Z - l.DirVector.Z * DirVector.X) < 0.0001)
{
return(new Vector3());
}
else
{
//избавиться от деления
//но как?
double t = (l.point.X - point.X) / (DirVector.X - l.DirVector.X);
return(new Vector3(point.X + t * DirVector.X, point.Y + t * DirVector.Y, point.Z + t * DirVector.Z));
}
}
public static List <Vector3> TriangleIntersection(Triangle t1, Triangle t2)
{
//плоскости не параллельны
if (t1.plane.A * t2.plane.B != t1.plane.B * t2.plane.A
||
t1.plane.B * t2.plane.C != t1.plane.C * t2.plane.B
||
t1.plane.A * t2.plane.C != t1.plane.C * t2.plane.A)
{
List <Vector3> I1 = new List <Vector3>(), I2 = new List <Vector3>();
Vector3 temp = t1.plane.Intersection(t2.Points[0], t2.Points[1]);
if (LineSegmentContainsPoint(t2.Points[0], t2.Points[1], temp))
{
I2.Add(temp);
}
temp = t1.plane.Intersection(t2.Points[1], t2.Points[2]);
if (LineSegmentContainsPoint(t2.Points[1], t2.Points[2], temp))
{
I2.Add(temp);
}
temp = t1.plane.Intersection(t2.Points[0], t2.Points[2]);
if (LineSegmentContainsPoint(t2.Points[0], t2.Points[2], temp))
{
I2.Add(temp);
}
temp = t2.plane.Intersection(t1.Points[0], t1.Points[1]);
if (LineSegmentContainsPoint(t1.Points[0], t1.Points[1], temp))
{
I1.Add(temp);
}
temp = t2.plane.Intersection(t1.Points[1], t1.Points[2]);
if (LineSegmentContainsPoint(t1.Points[1], t1.Points[2], temp))
{
I1.Add(temp);
}
temp = t2.plane.Intersection(t1.Points[0], t1.Points[2]);
if (LineSegmentContainsPoint(t1.Points[0], t1.Points[2], temp))
{
I1.Add(temp);
}
DeleteRepetitions(I1);
DeleteRepetitions(I2);
return(LineSegmentsOverlap(I1, I2));
}
else if (t1.plane == t2.plane)
{
List <Vector3> output = new List <Vector3>();
//List<Vector3> I1 = new List<Vector3>(), I2 = new List<Vector3>();
//StraightLine a = new StraightLine(t1.Points[0], t1.Points[1]),
// b = new StraightLine(t2.Points[0], t2.Points[1]);
//Vector3 temp = a.Intersection(b);
//if (StraightLine.StraightLineContainsPoint(a, temp)
// && StraightLine.StraightLineContainsPoint(b, temp))
// output.Add(temp);
//a = new StraightLine(t1.Points[1], t1.Points[2]);
//if (StraightLine.StraightLineContainsPoint(a, temp)
// && StraightLine.StraightLineContainsPoint(b, temp))
// output.Add(temp);
//a = new StraightLine(t1.Points[0], t1.Points[2]);
//if (StraightLine.StraightLineContainsPoint(a, temp)
// && StraightLine.StraightLineContainsPoint(b, temp))
// output.Add(temp);
StraightLine a, b;
Vector3 temp;
for (int i = 1; i < 3; i++)
{
for (int j = 1; j < 3; j++)
{
a = new StraightLine(t1.Points[i - 1], t1.Points[i]);
b = new StraightLine(t2.Points[j - 1], t2.Points[j]);
temp = a.Intersection(b);
if (StraightLine.StraightLineContainsPoint(a, temp) &&
StraightLine.StraightLineContainsPoint(b, temp))
{
output.Add(temp);
}
}
}
for (int j = 1; j < 3; j++)
{
a = new StraightLine(t1.Points[0], t1.Points[2]);
b = new StraightLine(t2.Points[j - 1], t2.Points[j]);
temp = a.Intersection(b);
if (StraightLine.StraightLineContainsPoint(a, temp) &&
StraightLine.StraightLineContainsPoint(b, temp))
{
output.Add(temp);
}
}
a = new StraightLine(t1.Points[0], t1.Points[2]);
b = new StraightLine(t2.Points[0], t2.Points[2]);
temp = a.Intersection(b);
if (StraightLine.StraightLineContainsPoint(a, temp) &&
StraightLine.StraightLineContainsPoint(b, temp))
{
output.Add(temp);
}
DeleteRepetitions(output);
//DeleteRepetitions(I2);
return(output);
}
else //параллельны
{
return(new List <Vector3>());
}
}
