MeshPlaneCut bug? about geometry3sharp HOT 3 CLOSED

public static DMesh3 ToDMesh3Merged(this Mesh mesh) {
    DMesh3 result = new DMesh3(bWantNormals: false);

    var verts = mesh.vertices;
    var tris = mesh.triangles;

    Dictionary<Vector3d, int> vertexHashToUnityVertexIndex = new Dictionary<Vector3d, int>();

    int[] unityVertexIndexToDMeshVertexIndex = new int[verts.Length];

    for (int i = 0; i < verts.Length; i++) {
        var vert = (Vector3d) verts[i];

        if (vertexHashToUnityVertexIndex.ContainsKey(vert)) {
            var mergedUnityVertexIndex = vertexHashToUnityVertexIndex[vert];
            unityVertexIndexToDMeshVertexIndex[i] = unityVertexIndexToDMeshVertexIndex[mergedUnityVertexIndex];
        } else {
            int vertId = result.AppendVertex(
                new NewVertexInfo {
                    v = vert,
                }
            );
            vertexHashToUnityVertexIndex[vert] = i;
            unityVertexIndexToDMeshVertexIndex[i] = vertId;
        }
    }

    for (int i = 0; i < tris.Length; i += 3) {
        result.AppendTriangle(
            unityVertexIndexToDMeshVertexIndex[tris[i]], 
            unityVertexIndexToDMeshVertexIndex[tris[i+1]], 
            unityVertexIndexToDMeshVertexIndex[tris[i+2]]);
    }

    return result;
}

Also, here is some code to split all vertices, if you want to do some flat-shaded stuff:

public static DMesh3 ToSplittedDMesh3(this DMesh3 dm) {

    DMesh3 result = new DMesh3(bWantNormals: false);

    foreach (var triIndex in dm.TriangleIndices()) {
        var tri = dm.GetTriangle(triIndex);

        var a = result.AppendVertex(dm.GetVertex(tri.a));
        var b = result.AppendVertex(dm.GetVertex(tri.b));
        var c = result.AppendVertex(dm.GetVertex(tri.c));
            
        result.AppendTriangle(a, b, c);
    }

    return result;

}