void Start()
{
if (MeshInfo == null)
{
MeshInfo = new MeshInfo(GetComponent <MeshFilter>().sharedMesh);
}
}
void SplitTriangle(MeshInfo top, MeshInfo bottom, Vector3 point, Vector3 normal, int[] newTriangles, int up, int down0, int down1, out Vector3 pos0, out Vector3 pos1)
{
Vector3 v0 = MeshInfo.vertices[up];
Vector3 v1 = MeshInfo.vertices[down0];
Vector3 v2 = MeshInfo.vertices[down1];
float topDot = Vector3.Dot(point - v0, normal);
float aScale = Mathf.Clamp01(topDot / Vector3.Dot(v1 - v0, normal));
float bScale = Mathf.Clamp01(topDot / Vector3.Dot(v2 - v0, normal));
Vector3 pos_a = v0 + (v1 - v0) * aScale;
Vector3 pos_b = v0 + (v2 - v0) * bScale;
Vector2 u0 = MeshInfo.uvs[up];
Vector2 u1 = MeshInfo.uvs[down0];
Vector2 u2 = MeshInfo.uvs[down1];
Vector3 uv_a = (u0 + (u1 - u0) * aScale);
Vector3 uv_b = (u0 + (u2 - u0) * bScale);
Vector3 n0 = MeshInfo.normals[up];
Vector3 n1 = MeshInfo.normals[down0];
Vector3 n2 = MeshInfo.normals[down1];
Vector3 normal_a = (n0 + (n1 - n0) * aScale).normalized;
Vector3 normal_b = (n0 + (n2 - n0) * bScale).normalized;
Vector4 t0 = MeshInfo.tangents[up];
Vector4 t1 = MeshInfo.tangents[down0];
Vector4 t2 = MeshInfo.tangents[down1];
Vector4 tangent_a = (t0 + (t1 - t0) * aScale).normalized;
Vector4 tangent_b = (t0 + (t2 - t0) * bScale).normalized;
tangent_a.w = t1.w;
tangent_b.w = t2.w;
int top_a = top.vertices.Count;
top.Add(pos_a, uv_a, normal_a, tangent_a);
int top_b = top.vertices.Count;
top.Add(pos_b, uv_b, normal_b, tangent_b);
top.triangles.Add(newTriangles[up]);
top.triangles.Add(top_a);
top.triangles.Add(top_b);
int down_a = bottom.vertices.Count;
bottom.Add(pos_a, uv_a, normal_a, tangent_a);
int down_b = bottom.vertices.Count;
bottom.Add(pos_b, uv_b, normal_b, tangent_b);
bottom.triangles.Add(newTriangles[down0]);
bottom.triangles.Add(newTriangles[down1]);
bottom.triangles.Add(down_b);
bottom.triangles.Add(newTriangles[down0]);
bottom.triangles.Add(down_b);
bottom.triangles.Add(down_a);
pos0 = pos_a;
pos1 = pos_b;
}
MeshInfo FastFillCutEdges(List <Vector3> edges, Vector3 pos, Vector3 normal)
{
if (edges.Count < 3)
{
throw new Exception("edges point less 3!");
}
for (int i = 0; i < edges.Count - 3; i++)
{
Vector3 t = edges[i + 1];
Vector3 temp = edges[i + 3];
for (int j = i + 2; j < edges.Count - 1; j += 2)
{
if ((edges[j] - t).sqrMagnitude < 1e-6)
{
edges[j] = edges[i + 2];
edges[i + 3] = edges[j + 1];
edges[j + 1] = temp;
break;
}
if ((edges[j + 1] - t).sqrMagnitude < 1e-6)
{
edges[j + 1] = edges[i + 2];
edges[i + 3] = edges[j];
edges[j] = temp;
break;
}
}
edges.RemoveAt(i + 2);
}
edges.RemoveAt(edges.Count - 1);
Vector4 tangent = MeshInfo.CalculateTangent(normal);
MeshInfo cutEdges = new MeshInfo();
for (int i = 0; i < edges.Count; i++)
{
cutEdges.Add(edges[i], Vector2.zero, normal, tangent);
}
int count = edges.Count - 1;
for (int i = 1; i < count; i++)
{
cutEdges.triangles.Add(0);
cutEdges.triangles.Add(i);
cutEdges.triangles.Add(i + 1);
}
cutEdges.center = MeshInfo.center;
cutEdges.size = MeshInfo.size;
cutEdges.MapperCube(uvRange);
return(cutEdges);
}
public void UpdateMesh(params MeshInfo[] info)
{
CombineInstance[] coms = new CombineInstance[info.Length];
for (int i = 0; i < info.Length; i++)
{
coms[i].mesh = info[i].GetMesh();
coms[i].transform = Matrix4x4.identity;
}
Mesh mesh = new Mesh();
mesh.CombineMeshes(coms);
mesh.RecalculateBounds();
//mesh.RecalculateNormals();
GetComponent <MeshFilter>().mesh = mesh;
GetComponent <MeshCollider>().sharedMesh = mesh;
MeshInfo = new MeshInfo(mesh);
MeshInfo.center = info[0].center;
MeshInfo.size = info[0].size;
}
public void Split(Plane plane)
{
Vector3 point = transform.InverseTransformPoint(plane.normal * -plane.distance);
Vector3 normal = transform.InverseTransformDirection(plane.normal);
normal.Scale(transform.localScale);
normal.Normalize();
MeshInfo a = new MeshInfo();
MeshInfo b = new MeshInfo();
//
bool[] above = new bool[MeshInfo.vertices.Count];
int[] newTriangles = new int[MeshInfo.vertices.Count];
for (int i = 0; i < newTriangles.Length; i++)
{
Vector3 vert = MeshInfo.vertices[i];
above[i] = Vector3.Dot(vert - point, normal) >= 0f;
if (above[i])
{
newTriangles[i] = a.vertices.Count;
a.Add(vert, MeshInfo.uvs[i], MeshInfo.normals[i], MeshInfo.tangents[i]);
}
else
{
newTriangles[i] = b.vertices.Count;
b.Add(vert, MeshInfo.uvs[i], MeshInfo.normals[i], MeshInfo.tangents[i]);
}
}
List <Vector3> cutPoint = new List <Vector3>();
int triangleCount = MeshInfo.triangles.Count / 3;
for (int i = 0; i < triangleCount; i++)
{
int _i0 = MeshInfo.triangles[i * 3];
int _i1 = MeshInfo.triangles[i * 3 + 1];
int _i2 = MeshInfo.triangles[i * 3 + 2];
bool _a0 = above[_i0];
bool _a1 = above[_i1];
bool _a2 = above[_i2];
if (_a0 && _a1 && _a2)
{
a.triangles.Add(newTriangles[_i0]);
a.triangles.Add(newTriangles[_i1]);
a.triangles.Add(newTriangles[_i2]);
}
else if (!_a0 && !_a1 && !_a2)
{
b.triangles.Add(newTriangles[_i0]);
b.triangles.Add(newTriangles[_i1]);
b.triangles.Add(newTriangles[_i2]);
}
else
{
int up, down0, down1;
if (_a1 == _a2 && _a0 != _a1)
{
up = _i0;
down0 = _i1;
down1 = _i2;
}
else if (_a2 == _a0 && _a1 != _a2)
{
up = _i1;
down0 = _i2;
down1 = _i0;
}
else
{
up = _i2;
down0 = _i0;
down1 = _i1;
}
Vector3 pos0, pos1;
if (above[up])
{
SplitTriangle(a, b, point, normal, newTriangles, up, down0, down1, out pos0, out pos1);
}
else
{
SplitTriangle(b, a, point, normal, newTriangles, up, down0, down1, out pos1, out pos0);
}
cutPoint.Add(pos0);
cutPoint.Add(pos1);
}
}
a.CombineVertices(0.001f);
a.center = MeshInfo.center;
a.size = MeshInfo.size;
b.CombineVertices(0.001f);
b.center = MeshInfo.center;
b.size = MeshInfo.size;
if (fill && cutPoint.Count > 2)
{
MeshInfo cut = FastFillCutEdges(cutPoint, point, normal);
Instantiate(gameObject).GetComponent <SplitObject>().UpdateMesh(b, cut);
cut.Reverse();
Instantiate(gameObject).GetComponent <SplitObject>().UpdateMesh(a, cut);
}
else
{
Instantiate(gameObject).GetComponent <SplitObject>().UpdateMesh(a);
Instantiate(gameObject).GetComponent <SplitObject>().UpdateMesh(b);
}
Destroy(gameObject);
}
MeshInfo FillCutEdges(List <Vector3> edges, Vector3 pos, Vector3 normal)
{
if (edges.Count < 3)
{
throw new Exception("edges point less 3!");
}
for (int i = 0; i < edges.Count; i++)
{
for (int j = i + 1; j < edges.Count; j++)
{
if ((edges[i] - edges[j]).sqrMagnitude < 1e-5f)
{
edges.RemoveAt(j);
}
}
}
Vector3 start = edges[0];
Vector3 dir = Vector3.zero;
for (int i = 1; i < edges.Count; i++)
{
if (dir == Vector3.zero)
{
dir = edges[i] - start;
}
}
dir.Normalize();
int count = edges.Count - 1;
for (int i = 2; i < count; i++)
{
Vector3 a = edges[i] - start;
float angle = Vector3.Dot(a.normalized, dir);
float dis = a.sqrMagnitude;
if (dis < 1e-6f)
{
continue;
}
bool change = false;
for (int j = i + 1; j < edges.Count; j++)
{
Vector3 b = edges[j] - start;
float _angle = Vector3.Dot(b.normalized, dir);
float _dis = b.sqrMagnitude;
bool next = _dis <= dis;
next = (angle - _angle < 0.001f) && (_angle > 0.9999f ? _dis < dis : _dis >= dis);
next = change ? false : next;
if (_angle - angle > 0.001f || next || _dis < 1e-6f)
{
if (_angle - angle > 0.001f)
{
change = true;
}
angle = _angle;
dis = _dis;
Vector3 temp;
temp = edges[i];
edges[i] = edges[j];
edges[j] = temp;
}
}
}
Vector4 tangent = MeshInfo.CalculateTangent(normal);
MeshInfo cutEdges = new MeshInfo();
for (int i = 0; i < edges.Count; i++)
{
cutEdges.Add(edges[i], Vector2.zero, normal, tangent);
}
for (int i = 1; i < count; i++)
{
cutEdges.triangles.Add(0);
cutEdges.triangles.Add(i);
cutEdges.triangles.Add(i + 1);
}
cutEdges.center = MeshInfo.center;
cutEdges.size = MeshInfo.size;
cutEdges.MapperCube(uvRange);
return(cutEdges);
}
