public void PointNearestToOtherRay(TRay r, ref float point)
{
Vector3 t = Vector3.Cross(dir, r.dir);
TPlane p = new TPlane(Vector3.Cross(t, r.dir), r.pos);
Inters(p, ref point);
}
public bool Inters(TPlane plane, ref float t)
{
float v = Vector3.Dot(plane.normal, dir);
if (v == 0)
{
return(false);
}
t = (plane.dist - Vector3.Dot(pos, plane.normal)) / v;
return(t > 0);
}
void CutTriangleByPlane(TPlane plane, int tri)
{
TMeshTri t = triangle[tri];
float
d0 = plane.DistToPlane(pos[t.p0]),
d1 = plane.DistToPlane(pos[t.p1]),
d2 = plane.DistToPlane(pos[t.p2]);
bool d0_sign = d0 >= 0;
bool d1_sign = d1 >= 0;
bool d2_sign = d2 >= 0;
int vert0 = -1, vert1 = -1, vert2 = -1;
{
int zero_count = 0;
if (d0 == 0.0f)
{
zero_count++;
}
if (d1 == 0.0f)
{
zero_count++;
}
if (d2 == 0.0f)
{
zero_count++;
}
if (zero_count == 3 || zero_count == 2)
{
return;
}
}
if (d0 == 0.0f || d1 == 0.0f || d2 == 0.0f)
{
float x = 0;
if (d0 == 0.0f)
{
if (d1_sign == d2_sign)
{
return;
}
vert0 = 0;
vert1 = 1;
vert2 = 2;
x = d1 / (d1 - d2);
}
else if (d1 == 0.0f)
{
if (d0_sign == d2_sign)
{
return;
}
vert0 = 1;
vert1 = 2;
vert2 = 0;
x = d2 / (d2 - d0);
}
else// if (d2 == 0.0f)
{
if (d0_sign == d1_sign)
{
return;
}
vert0 = 2;
vert1 = 0;
vert2 = 1;
x = d0 / (d0 - d1);
}
Vector3 new_pos = Blend(pos[t.GetPos(vert1)], pos[t.GetPos(vert2)], x);
Vector3 new_normal = Blend(normal[t.GetNormal(vert1)], normal[t.GetNormal(vert2)], x);
new_normal.Normalize();
Debug.Assert(!float.IsNaN(new_pos.X) && !float.IsNaN(new_pos.Y) && !float.IsNaN(new_pos.Z));
pos.Add(new_pos);
normal.Add(new_normal);
TMeshTri temp = triangle[tri];
triangle[tri] = new TMeshTri(
temp.GetPos(vert0), temp.GetPos(vert1), pos.High,
temp.GetNormal(vert0), temp.GetNormal(vert1), normal.High,
0, 0, 0);
triangle.Add(new TMeshTri(
temp.GetPos(vert0), pos.High, temp.GetPos(vert2),
temp.GetNormal(vert0), normal.High, temp.GetNormal(vert2),
0, 0, 0));
}
else
{
float x1 = 0, x2 = 0;
if ((d0_sign == d1_sign) && (d0_sign != d2_sign))
{
vert0 = 2;
vert1 = 0;
vert2 = 1;
x1 = d2 / (d2 - d0);
x2 = d2 / (d2 - d1);
}
else if ((d0_sign == d2_sign) && (d0_sign != d1_sign))
{
vert0 = 1;
vert1 = 2;
vert2 = 0;
x1 = d1 / (d1 - d2);
x2 = d1 / (d1 - d0);
}
else if ((d1_sign == d2_sign) && (d0_sign != d1_sign))
{
vert0 = 0;
vert1 = 1;
vert2 = 2;
x1 = d0 / (d0 - d1);
x2 = d0 / (d0 - d2);
}
else
{
return; //треугольники могут пересекаются из-за неточностей
}
Vector3 new_pos1 = Blend(pos[t.GetPos(vert0)], pos[t.GetPos(vert1)], x1);
Vector3 new_pos2 = Blend(pos[t.GetPos(vert0)], pos[t.GetPos(vert2)], x2);
Vector3 new_normal1 = Blend(normal[t.GetNormal(vert0)], normal[t.GetNormal(vert1)], x1);
Vector3 new_normal2 = Blend(normal[t.GetNormal(vert0)], normal[t.GetNormal(vert2)], x2);
new_normal1.Normalize();
new_normal2.Normalize();
pos.Add(new_pos1);
pos.Add(new_pos2);
Debug.Assert(!float.IsNaN(new_pos1.X) && !float.IsNaN(new_pos1.Y) && !float.IsNaN(new_pos1.Z));
Debug.Assert(!float.IsNaN(new_pos2.X) && !float.IsNaN(new_pos2.Y) && !float.IsNaN(new_pos2.Z));
normal.Add(new_normal1);
normal.Add(new_normal2);
TMeshTri temp = triangle[tri];
//TODO выбирать наиболее короткое ребро
triangle[tri] = new TMeshTri(
temp.GetPos(vert0), pos.High - 1, pos.High,
temp.GetNormal(vert0), normal.High - 1, normal.High,
0, 0, 0);
triangle.Add(new TMeshTri(
pos.High - 1, temp.GetPos(vert1), temp.GetPos(vert2),
normal.High - 1, temp.GetNormal(vert1), temp.GetNormal(vert2),
0, 0, 0));
triangle.Add(new TMeshTri(
pos.High - 1, temp.GetPos(vert2), pos.High,
normal.High - 1, temp.GetNormal(vert2), normal.High,
0, 0, 0));
}
}
