public void Cut(Vector3 p0, Vector3 p1, Vector3 p2)
{
TTriangle tri = new TTriangle(p0, p1, p2);
int high = triangle.High;
for (int i = 0; i <= high; i++)
{
if (tri.Inters(pos[triangle[i].p0], pos[triangle[i].p1], pos[triangle[i].p2]))
{
Vector3 normal = (Vector3.Cross((p1 - p0), (p2 - p0)));
normal.Normalize();
CutTriangleByPlane(new TPlane(normal, p0), i);
}
}
}
public bool Inters(TTriangle tri)
{
//плоскости треугольников
Vector3 N0 = Vector3.Cross(p0 - p1, p0 - p2), N1 = Vector3.Cross(tri.p0 - tri.p1, tri.p0 - tri.p2);
float d0 = -Vector3.Dot(p0, N0);
float d1 = -Vector3.Dot(tri.p0, N1);
//расстояние от вершин первого треугольника до плоскости второго
float d0T0 = Vector3.Dot(p0, N1) + d1;
float d1T0 = Vector3.Dot(p1, N1) + d1;
float d2T0 = Vector3.Dot(p2, N1) + d1;
Vector3 line = Vector3.Cross(N0, N1);
if (d0T0 == 0 && d1T0 == 0 && d2T0 == 0)
{
return(false); //треугольники лежат в одной плоскости
}
if (((d0T0 > 0) == (d1T0 > 0)) && ((d0T0 > 0) == (d2T0 > 0)))
{
return(false);
}
float d0T1 = Vector3.Dot(tri.p0, N0) + d0;
float d1T1 = Vector3.Dot(tri.p1, N0) + d0;
float d2T1 = Vector3.Dot(tri.p2, N0) + d0;
if (((d0T1 > 0) == (d1T1 > 0)) && ((d0T1 > 0) == (d2T1 > 0)))
{
return(false);
}
//вычисляем проекции ребер треугольников на линию
float t0T0, t1T0, t0T1, t1T1;
if ((d0T0 > 0) == (d1T0 > 0))
{
t0T0 = GetInterval(line, p1, p2, d1T0, d2T0);
t1T0 = GetInterval(line, p0, p2, d0T0, d2T0);
}
else if ((d2T0 > 0) == (d1T0 > 0))
{
t0T0 = GetInterval(line, p2, p0, d2T0, d0T0);
t1T0 = GetInterval(line, p1, p0, d1T0, d0T0);
}
else// if ((d0T0 > 0) == (d2T0 > 0))
{
t0T0 = GetInterval(line, p0, p1, d0T0, d1T0);
t1T0 = GetInterval(line, p2, p1, d2T0, d1T0);
}
if ((d0T1 > 0) == (d1T1 > 0))
{
t0T1 = GetInterval(line, tri.p1, tri.p2, d1T1, d2T1);
t1T1 = GetInterval(line, tri.p0, tri.p2, d0T1, d2T1);
}
else if ((d2T1 > 0) == (d1T1 > 0))
{
t0T1 = GetInterval(line, tri.p2, tri.p0, d2T1, d0T1);
t1T1 = GetInterval(line, tri.p1, tri.p0, d1T1, d0T1);
}
else// if ((d0T1 > 0) == (d2T1 > 0))
{
t0T1 = GetInterval(line, tri.p0, tri.p1, d0T1, d1T1);
t1T1 = GetInterval(line, tri.p2, tri.p1, d2T1, d1T1);
}
//определяем пересечение проекций
float temp;
if (t0T0 > t1T0)
{
temp = t0T0; t0T0 = t1T0; t1T0 = temp;
}
if (t0T1 > t1T1)
{
temp = t0T1; t0T1 = t1T1; t1T1 = temp;
}
return(t0T1 <= t1T0 && t0T0 <= t1T1);
}
