/// <summary>
/// Slice a mesh by the slice plane.
/// We assume the plane is already in the mesh's local coordinate frame
/// Returns posMesh and negMesh, which are the resuling meshes on both sides of the plane
/// (posMesh on the same side as the plane's normal, negMesh on the opposite side)
/// </summary>
public bool SliceMesh(Mesh mesh, ref Plane slice)
{
// Let's always fill the vertices array so that we can access it even if the mesh didn't intersect
mesh.GetVertices(ogVertices);
// 1. Verify if the bounds intersect first
if (!Intersections.BoundPlaneIntersect(mesh, ref slice))
{
return(false);
}
mesh.GetTriangles(ogTriangles, 0);
mesh.GetNormals(ogNormals);
mesh.GetUVs(0, ogUvs);
PositiveMesh.Clear();
NegativeMesh.Clear();
addedPairs.Clear();
// 2. Separate old vertices in new meshes
for (int i = 0; i < ogVertices.Count; ++i)
{
if (slice.GetDistanceToPoint(ogVertices[i]) >= 0)
{
PositiveMesh.AddVertex(ogVertices, ogNormals, ogUvs, i);
}
else
{
NegativeMesh.AddVertex(ogVertices, ogNormals, ogUvs, i);
}
}
// 2.5 : If one of the mesh has no vertices, then it doesn't intersect
if (NegativeMesh.vertices.Count == 0 || PositiveMesh.vertices.Count == 0)
{
return(false);
}
// 3. Separate triangles and cut those that intersect the plane
for (int i = 0; i < ogTriangles.Count; i += 3)
{
if (intersect.TrianglePlaneIntersect(ogVertices, ogUvs, ogTriangles, i, ref slice, PositiveMesh, NegativeMesh, intersectPair))
{
addedPairs.AddRange(intersectPair);
}
}
if (addedPairs.Count > 0)
{
//FillBoundaryGeneral(addedPairs);
FillBoundaryFace(addedPairs);
return(true);
}
else
{
throw new UnityException("Error: if added pairs is empty, we should have returned false earlier");
}
}
/// <summary>
/// Разрезание меша по плоскости разреза.
/// Мы предполагаем, что плоскость уже находится в локальной системе координат меша
/// Возвращает posMesh и negMesh, которые являются мешами по разные стороны от плоскости разреза
/// (posMesh на стороне нормали плоскости разреза, negMesh на противоположной стороне)
/// </summary>
public bool SliceMesh(Mesh mesh, ref Plane slice)
{
// Заполняем массив вершин, чтобы мы могли получить к нему доступ, даже если не было пересечения
mesh.GetVertices(ogVertices);
if (!Intersections.BoundPlaneIntersect(mesh, ref slice))
{
return(false);
}
mesh.GetTriangles(ogTriangles, 0);
mesh.GetNormals(ogNormals);
mesh.GetUVs(0, ogUvs);
PositiveMesh.Clear();
NegativeMesh.Clear();
addedPairs.Clear();
// Распределение старых вершин в новых мешах
for (int i = 0; i < ogVertices.Count; ++i)
{
if (slice.GetDistanceToPoint(ogVertices[i]) >= 0)
{
PositiveMesh.AddVertex(ogVertices, ogNormals, ogUvs, i);
}
else
{
NegativeMesh.AddVertex(ogVertices, ogNormals, ogUvs, i);
}
}
// Если у одной из мешей нет вершин, то не пересекается
if (NegativeMesh.vertices.Count == 0 || PositiveMesh.vertices.Count == 0)
{
return(false);
}
// Разделяй треугольники и разрезай те, которые пересекают плоскость
for (int i = 0; i < ogTriangles.Count; i += 3)
{
if (intersect.TrianglePlaneIntersect(ogVertices, ogUvs, ogTriangles, i, ref slice, PositiveMesh, NegativeMesh, intersectPair))
{
addedPairs.AddRange(intersectPair);
}
}
if (addedPairs.Count > 0)
{
FillBoundaryFace(addedPairs);
return(true);
}
else
{
throw new UnityException("Ошибка: если добавленные пары пустые, мы должны были вернуть false раньше");
}
}
/// <summary>Cut mesh along bisector line and keep only the half containing the center point.</summary>
public static TempMesh Cut(Mesh mesh, Line bisector, Vector2 center)
{
var initialArraySize = 256;
TempMesh tempMesh = new TempMesh(initialArraySize);
TempMesh trashMesh = new TempMesh(initialArraySize);
var intersect = new Intersections();
var addedPairs = new List <Vector3>(initialArraySize);
var ogVertices = new List <Vector3>(initialArraySize);
var ogNormals = new List <Vector3>(initialArraySize);
var ogUvs = new List <Vector2>(initialArraySize);
var ogTriangles = new List <int>(initialArraySize * 3);
var intersectPair = new Vector3[2];
var tempTriangle = new Vector3[3];
// Let's always fill the vertices array so that we can access it even if the mesh didn't intersect
mesh.GetVertices(ogVertices);
mesh.GetTriangles(ogTriangles, 0);
mesh.GetNormals(ogNormals);
mesh.GetUVs(0, ogUvs);
tempMesh.Clear();
trashMesh.Clear();
for (int i = 0; i < ogVertices.Count; ++i)
{
var test = bisector.isLeft(ogVertices[i]);
// Debug.Log(test);
if (test)
{
tempMesh.AddVertex(ogVertices, ogNormals, ogUvs, i);
}
else
{
trashMesh.AddVertex(ogVertices, ogNormals, ogUvs, i);
}
}
Plane slice = bisector.GetPlane();
// 3. Separate triangles and cut those that intersect the plane
for (int i = 0; i < ogTriangles.Count; i += 3)
{
if (intersect.TrianglePlaneIntersect(ogVertices, ogUvs, ogTriangles, i, ref slice, tempMesh, trashMesh, intersectPair))
{
addedPairs.AddRange(intersectPair);
}
}
if (addedPairs.Count > 0)
{
//FillBoundaryGeneral(addedPairs);
MeshTools.FillBoundaryFace(tempMesh, addedPairs, ref tempTriangle);
return(tempMesh);
}
else
{
throw new UnityException("Error: if added pairs is empty, we should have returned false earlier");
}
return(tempMesh);
}
