/// <summary>
/// Add the mesh data to the correct side and calulate normals
/// </summary>
/// <param name="side"></param>
/// <param name="vertex1"></param>
/// <param name="vertex1Uv"></param>
/// <param name="vertex2"></param>
/// <param name="vertex2Uv"></param>
/// <param name="vertex3"></param>
/// <param name="vertex3Uv"></param>
/// <param name="shareVertices"></param>
private void AddTrianglesNormalAndUvs(MeshSide side, Vector3 vertex1, Vector3?normal1, Vector2 uv1, Vector3 vertex2, Vector3?normal2, Vector2 uv2, Vector3 vertex3, Vector3?normal3, Vector2 uv3, bool shareVertices, bool addFirst)
{
if (side == MeshSide.Positive)
{
AddTrianglesNormalsAndUvs(ref _positiveSideVertices, ref _positiveSideTriangles, ref _positiveSideNormals, ref _positiveSideUvs, vertex1, normal1, uv1, vertex2, normal2, uv2, vertex3, normal3, uv3, shareVertices, addFirst);
}
else
{
AddTrianglesNormalsAndUvs(ref _negativeSideVertices, ref _negativeSideTriangles, ref _negativeSideNormals, ref _negativeSideUvs, vertex1, normal1, uv1, vertex2, normal2, uv2, vertex3, normal3, uv3, shareVertices, addFirst);
}
}
/// <summary>
/// Setup the mesh object for the specified side
/// </summary>
/// <param name="side"></param>
private void SetMeshData(MeshSide side)
{
if (side == MeshSide.Positive)
{
_positiveSideMesh.vertices = _positiveSideVertices.ToArray();
_positiveSideMesh.triangles = _positiveSideTriangles.ToArray();
_positiveSideMesh.normals = _positiveSideNormals.ToArray();
_positiveSideMesh.uv = _positiveSideUvs.ToArray();
}
else
{
_negativeSideMesh.vertices = _negativeSideVertices.ToArray();
_negativeSideMesh.triangles = _negativeSideTriangles.ToArray();
_negativeSideMesh.normals = _negativeSideNormals.ToArray();
_negativeSideMesh.uv = _negativeSideUvs.ToArray();
}
}
/// <summary>
/// Compute the positive and negative meshes based on the plane and mesh
/// </summary>
private void ComputeNewMeshes()
{
int[] meshTriangles = _mesh.triangles;
Vector3[] meshVerts = _mesh.vertices;
Vector3[] meshNormals = _mesh.normals;
Vector2[] meshUvs = _mesh.uv;
for (int i = 0; i < meshTriangles.Length; i += 3)
{
//We need the verts in order so that we know which way to wind our new mesh triangles.
Vector3 vert1 = meshVerts[meshTriangles[i]];
int vert1Index = Array.IndexOf(meshVerts, vert1);
Vector2 uv1 = meshUvs[vert1Index];
Vector3 normal1 = meshNormals[vert1Index];
bool vert1Side = _plane.GetSide(vert1);
Vector3 vert2 = meshVerts[meshTriangles[i + 1]];
int vert2Index = Array.IndexOf(meshVerts, vert2);
Vector2 uv2 = meshUvs[vert2Index];
Vector3 normal2 = meshNormals[vert2Index];
bool vert2Side = _plane.GetSide(vert2);
Vector3 vert3 = meshVerts[meshTriangles[i + 2]];
bool vert3Side = _plane.GetSide(vert3);
int vert3Index = Array.IndexOf(meshVerts, vert3);
Vector3 normal3 = meshNormals[vert3Index];
Vector2 uv3 = meshUvs[vert3Index];
//All verts are on the same side
if (vert1Side == vert2Side && vert2Side == vert3Side)
{
//Add the relevant triangle
MeshSide side = (vert1Side) ? MeshSide.Positive : MeshSide.Negative;
AddTrianglesNormalAndUvs(side, vert1, normal1, uv1, vert2, normal2, uv2, vert3, normal3, uv3, true, false);
}
else
{
//we need the two points where the plane intersects the triangle.
Vector3 intersection1;
Vector3 intersection2;
Vector2 intersection1Uv;
Vector2 intersection2Uv;
MeshSide side1 = (vert1Side) ? MeshSide.Positive : MeshSide.Negative;
MeshSide side2 = (vert1Side) ? MeshSide.Negative : MeshSide.Positive;
//vert 1 and 2 are on the same side
if (vert1Side == vert2Side)
{
//Cast a ray from v2 to v3 and from v3 to v1 to get the intersections
intersection1 = GetRayPlaneIntersectionPointAndUv(vert2, uv2, vert3, uv3, out intersection1Uv);
intersection2 = GetRayPlaneIntersectionPointAndUv(vert3, uv3, vert1, uv1, out intersection2Uv);
//Add the positive or negative triangles
AddTrianglesNormalAndUvs(side1, vert1, null, uv1, vert2, null, uv2, intersection1, null, intersection1Uv, _useSharedVertices, false);
AddTrianglesNormalAndUvs(side1, vert1, null, uv1, intersection1, null, intersection1Uv, intersection2, null, intersection2Uv, _useSharedVertices, false);
AddTrianglesNormalAndUvs(side2, intersection1, null, intersection1Uv, vert3, null, uv3, intersection2, null, intersection2Uv, _useSharedVertices, false);
}
//vert 1 and 3 are on the same side
else if (vert1Side == vert3Side)
{
//Cast a ray from v1 to v2 and from v2 to v3 to get the intersections
intersection1 = GetRayPlaneIntersectionPointAndUv(vert1, uv1, vert2, uv2, out intersection1Uv);
intersection2 = GetRayPlaneIntersectionPointAndUv(vert2, uv2, vert3, uv3, out intersection2Uv);
//Add the positive triangles
AddTrianglesNormalAndUvs(side1, vert1, null, uv1, intersection1, null, intersection1Uv, vert3, null, uv3, _useSharedVertices, false);
AddTrianglesNormalAndUvs(side1, intersection1, null, intersection1Uv, intersection2, null, intersection2Uv, vert3, null, uv3, _useSharedVertices, false);
AddTrianglesNormalAndUvs(side2, intersection1, null, intersection1Uv, vert2, null, uv2, intersection2, null, intersection2Uv, _useSharedVertices, false);
}
//Vert1 is alone
else
{
//Cast a ray from v1 to v2 and from v1 to v3 to get the intersections
intersection1 = GetRayPlaneIntersectionPointAndUv(vert1, uv1, vert2, uv2, out intersection1Uv);
intersection2 = GetRayPlaneIntersectionPointAndUv(vert1, uv1, vert3, uv3, out intersection2Uv);
AddTrianglesNormalAndUvs(side1, vert1, null, uv1, intersection1, null, intersection1Uv, intersection2, null, intersection2Uv, _useSharedVertices, false);
AddTrianglesNormalAndUvs(side2, intersection1, null, intersection1Uv, vert2, null, uv2, vert3, null, uv3, _useSharedVertices, false);
AddTrianglesNormalAndUvs(side2, intersection1, null, intersection1Uv, vert3, null, uv3, intersection2, null, intersection2Uv, _useSharedVertices, false);
}
//Add the newly created points on the plane.
_pointsAlongPlane.Add(intersection1);
_pointsAlongPlane.Add(intersection2);
}
}
//If the object is solid, join the new points along the plane otherwise do the reverse winding
if (_isSolid)
{
JoinPointsAlongPlane();
}
else if (_createReverseTriangleWindings)
{
AddReverseTriangleWinding();
}
if (_smoothVertices)
{
SmoothVertices();
}
}