public void Split(Vector3 localPlaneNormal, Vector3 localPlaneDir, Vector3 localPointStart, Vector3 localPointEnd, int faceStart, int faceEnd, bool fillCut)
{
Debug.LogFormat("Split Point {0} {1} Face {2} {3} Normal {4}", localPointStart, localPointEnd, faceStart, faceEnd, localPlaneNormal);
Clear();
planeNormal = localPlaneNormal;
planeDir = localPlaneDir;
indexStart = faceStart;
indexEnd = faceEnd;
pointStart = localPointStart;
pointEnd = localPointEnd;
// 剪切范围
Vector3 center = (pointEnd + pointStart) / 2f;
if (localPlaneNormal == Vector3.zero)
{
localPlaneNormal = Vector3.up;
}
bool[] vertexAbovePlane = new bool[vertices.Count];
for (int i = 0; i < vertices.Count; i++)
{
Vector3 vertex = vertices[i];
bool abovePlane = Vector3.Dot(vertex - pointEnd, localPlaneNormal) >= 0.0f;
vertexAbovePlane [i] = abovePlane;
}
// remove
int triangleCount = indices.Count / 3;
for (int i = 0; i < triangleCount; i++)
{
int index0 = indices [i * 3 + 0];
int index1 = indices [i * 3 + 1];
int index2 = indices [i * 3 + 2];
bool above0 = vertexAbovePlane [index0];
bool above1 = vertexAbovePlane [index1];
bool above2 = vertexAbovePlane [index2];
if ((above0 && above1 && above2) || (!above0 && !above1 && !above2))
{
// 保持不变
//Debug.LogFormat(" old {0} {1} {2}", index0, index1, index2);
}
else
{
Vector3 v0 = vertices [index0];
Vector3 v1 = vertices [index1];
Vector3 v2 = vertices [index2];
float a1 = Vector3.Dot(v0 - pointEnd, localPlaneNormal);
float a2 = Vector3.Dot(v1 - pointEnd, localPlaneNormal);
float a3 = Vector3.Dot(v2 - pointEnd, localPlaneNormal);
// 切割点在tri上投影
Vector3 fN = Vector3.Cross(v1 - v0, v2 - v0).normalized;
Vector3 projS = MathUtils.LineIntersectPlane(fN, v0, planeDir, pointStart);
Vector3 projE = MathUtils.LineIntersectPlane(fN, v0, planeDir, pointEnd);
bool InS = MathUtils.PointInTriangle(v0, v1, v2, projS);
bool InE = MathUtils.PointInTriangle(v0, v1, v2, projE);
bool b1 = MathUtils.LineIntersect(v0, v1, projS, projE);
bool b2 = MathUtils.LineIntersect(v0, v2, projS, projE);
bool b3 = MathUtils.LineIntersect(v1, v2, projS, projE);
//Debug.LogFormat ("Face {0} intersection {1} {2} {3}", i, b1, b2, b3);
if (!InS && !InE && !b1 && !b2 && !b3)
{
// 不相交
tri_backlist.Add(i);
}
else
{
// 检查到切割范围内？
float d0 = MathUtils.PointDistPlane(planeDir, center, v0);
float d1 = MathUtils.PointDistPlane(planeDir, center, v1);
float d2 = MathUtils.PointDistPlane(planeDir, center, v2);
if (d0 > 1 && d1 > 1 && d2 > 1)
{
tri_backlist.Add(i);
}
}
}
}
IList <Vector3> cutEdges;
AssignTriangles(vertexAbovePlane, localPointStart, localPlaneNormal, out cutEdges);
if (fillCut)
{
cutEdges.Clear();
cutEdges.Add(pointStart);
cutEdges.Add(pointStart + planeDir);
cutEdges.Add(pointStart + planeDir);
cutEdges.Add(pointEnd + planeDir);
cutEdges.Add(pointEnd + planeDir);
cutEdges.Add(pointEnd);
cutEdges.Add(pointEnd);
cutEdges.Add(pointStart);
FillCutEdges(cutEdges, localPlaneNormal);
}
// update mesh & mass springs
softbody.SetMesh(GetNewMesh(), _vertices1, _vertices2, _tris);
}
