public static Mesh Cylinder(int segments, int slices, float radius, float height, Mesh m = null)
{
if (slices < 2)
{
throw new ArgumentException("Must be more than 2 slices");
}
height /= 2f;
m = m ?? new Mesh();
Vertex[][] sliceVerts = new Vertex[slices][];
for (int i = 0; i < slices; i++)
{
sliceVerts[i] = new Vertex[segments];
}
float angle = 0;
float step = MathHelper.TwoPi / (float)segments;
for (int segment = 0; segment < segments; segment++)
{
Vector2 xy = new Vector2((float)Math.Sin(angle), (float)Math.Cos(angle));
for (int slice = 0; slice < slices; slice++)
{
float l = slice / (float)slices;
float z = MathHelper.Lerp(-height, height, l);
sliceVerts[slice][segment] = m.GetVertex(new Vector3(xy, z), "slice:" + slice + " seg:" + segment);
}
angle += step;
}
m.GetFace(sliceVerts[0].Reverse());
m.GetFace(sliceVerts[slices - 1]);
for (int segment = 0; segment < segments; segment++)
{
for (int slice = 0; slice < slices - 1; slice++)
{
m.GetFace(
sliceVerts[slice][segment],
sliceVerts[slice][(segment + 1) % segments],
sliceVerts[slice + 1][(segment + 1) % segments],
sliceVerts[slice + 1][segment]
);
}
}
return(m);
}
public void MergeEdgesAroundALoneFace()
{
Mesh m = new Mesh();
var a = m.GetVertex(new Vector3(0, 0, 1), "a");
var b = m.GetVertex(new Vector3(0, 0, 2), "b");
var c = m.GetVertex(new Vector3(0, 0, 3), "c");
var d = m.GetVertex(new Vector3(0, 0, 4), "d");
var abcd = m.GetFace(a, b, c, d);
var ab = m.GetEdge(a, b);
Assert.AreEqual(8, m.HalfEdges.Count());
ab.Merge();
Assert.AreEqual(c, ab.End);
Assert.AreEqual(ab.Next, m.GetEdge(c, d, false));
Assert.IsNull(m.GetEdge(a, b, false));
Assert.AreEqual(ab, m.GetEdge(d, a, false).Next);
Assert.AreEqual(6, m.HalfEdges.Count());
Assert.AreEqual(3, m.HalfEdges.Where(e => e.Face == null).Count());
Assert.AreEqual(0, m.HalfEdges.Where(e => e.Face != null && e.Next == null).Count());
Assert.AreEqual(0, m.HalfEdges.Where(e => e.Face == null && e.Next != null).Count());
}
/// <summary>
/// Replaces a face with a set of faces with 3 vertices
/// </summary>
/// <param name="f">The f.</param>
/// <param name="m">The m.</param>
public static void TriangulateMutator(Face f, Mesh m)
{
int c = 0;
foreach (var v in f.Vertices)
{
c++;
if (c > 3)
{
break;
}
}
if (c == 3)
{
return;
}
var verts = f.TriangulateFromSinglePoint.ToArray();
f.Delete();
for (int i = 0; i < verts.Length; i += 3)
{
m.GetFace(verts[i], verts[i + 1], verts[i + 2]);
}
}
public void ConstructTriangle()
{
Mesh m = new Mesh();
//oh hai
var a = m.GetVertex(Vector3.Zero);
var b = m.GetVertex(Vector3.Zero);
var c = m.GetVertex(Vector3.Zero);
var f = m.GetFace(a, b, c);
}
public void DeleteAndReplaceSurroundedFace()
{
Mesh m = new Mesh();
var a = m.GetVertex(new Vector3(1, 0, 0));
var abp = m.GetVertex(new Vector3(0, 1, 0));
var b = m.GetVertex(new Vector3(2, 0, 0));
var bcp = m.GetVertex(new Vector3(0, 2, 0));
var c = m.GetVertex(new Vector3(3, 0, 0));
var cap = m.GetVertex(new Vector3(0, 3, 0));
var f = m.GetFace(a, b, c);
var ab = m.GetFace(a, abp, b);
var bc = m.GetFace(b, bcp, c);
var ca = m.GetFace(c, cap, a);
var fEdges = f.Edges.ToList();
f.Delete();
Assert.AreEqual(3, m.Faces.Count());
foreach (var e in fEdges)
{
Assert.IsNull(e.Face);
Assert.IsNull(e.Next);
}
foreach (var e in fEdges)
{
Assert.IsNotNull(e.Twin.Face);
Assert.IsNotNull(e.Twin.Next);
}
f = m.GetFace(b, c, m.GetVertex(Vector3.Zero));
}
public static Mesh Icosahedron(Mesh m = null)
{
m = m ?? new Mesh();
var vertices = icosahedronVertices.Select((a, i) => m.GetVertex(a, i.ToString())).ToArray();
for (int i = 0; i < icosahedronIndices.Length; i += 3)
{
var a = vertices[icosahedronIndices[i + 2]];
var b = vertices[icosahedronIndices[i + 1]];
var c = vertices[icosahedronIndices[i]];
Face f = m.GetFace(a, b, c);
}
return(m);
}
/// <summary>
/// Inserts a midpoint into this face
/// Deletes this face
/// </summary>
/// <param name="midpoint">The midpoint.</param>
public void InsertMidpoint(Vertex midpoint)
{
Mesh.InformSplitMidpointBegin(this, midpoint);
var edges = Edges.ToArray();
Delete();
for (int i = 0; i < edges.Length; i++)
{
var v1 = edges[i].End;
var v2 = edges[(i + 1) % edges.Length].End;
Mesh.GetFace(v1, v2, midpoint);
}
Mesh.InformSplitMidpointEnd(this, midpoint);
}
public static Mesh Icosahedron(Func<Vector3, Vertex> factory = null)
{
Mesh m = new Mesh(factory ?? defaultFactory);
var vertices = icosahedronVertices.Select(a => m.GetVertex(a)).ToArray();
for (int i = 0; i < icosahedronIndices.Length; i += 3)
{
var a = vertices[icosahedronIndices[i]];
var b = vertices[icosahedronIndices[i + 1]];
var c = vertices[icosahedronIndices[i + 2]];
Face f = m.GetFace(a, b, c);
}
return m;
}
public void DeleteLoneFace()
{
Mesh m = new Mesh();
var a = m.GetVertex(new Vector3(1, 0, 0));
var b = m.GetVertex(new Vector3(2, 0, 0));
var c = m.GetVertex(new Vector3(3, 0, 0));
var f = m.GetFace(a, b, c);
f.Delete();
foreach (var edge in m.HalfEdges)
{
Assert.IsNull(edge.Face);
Assert.IsNull(edge.Next);
Assert.IsNull(edge.Twin.Face);
Assert.IsNull(edge.Twin.Next);
}
Assert.AreEqual(0, m.Faces.Count());
}
/// <summary>
/// Construct a cuboid graph on the given vertices, winding around { top1, top2, top3, top4 } and then all neighbours accordingly
/// </summary>
/// <param name="top1"></param>
/// <param name="top2"></param>
/// <param name="top3"></param>
/// <param name="top4"></param>
/// <param name="bottom1"></param>
/// <param name="bottom2"></param>
/// <param name="bottom3"></param>
/// <param name="bottom4"></param>
/// <param name="factory"></param>
/// <returns></returns>
public static Mesh Cuboid(Vector3 top1, Vector3 top2, Vector3 top3, Vector3 top4, Vector3 bottom1, Vector3 bottom2, Vector3 bottom3, Vector3 bottom4, Mesh m = null)
{
m = m ?? new Mesh();
Vertex t1 = m.GetVertex(top1);
Vertex t2 = m.GetVertex(top2);
Vertex t3 = m.GetVertex(top3);
Vertex t4 = m.GetVertex(top4);
Vertex b5 = m.GetVertex(bottom1);
Vertex b6 = m.GetVertex(bottom2);
Vertex b7 = m.GetVertex(bottom3);
Vertex b8 = m.GetVertex(bottom4);
Face t1234 = m.GetFace(t4, t3, t2, t1);
Face t21b56 = m.GetFace(b6, b5, t1, t2);
Face t32b67 = m.GetFace(b7, b6, t2, t3);
Face t43b78 = m.GetFace(b8, b7, t3, t4);
Face t14b85 = m.GetFace(b5, b8, t4, t1);
Face b6587 = m.GetFace(b7, b8, b5, b6);
return(m);
}
public void GetSameFaceTwiceWithDifferentVertexIndices()
{
Mesh m = new Mesh();
Vertex a = m.GetVertex(new Vector3(0, 0, 1));
Vertex b = m.GetVertex(new Vector3(0, 0, 2));
Vertex c = m.GetVertex(new Vector3(0, 0, 3));
Vertex d = m.GetVertex(new Vector3(0, 0, 4));
Face abcd = m.GetFace(a, b, c, d);
Face bcda = m.GetFace(b, c, d, a);
Face cdab = m.GetFace(c, d, a, b);
Face dabc = m.GetFace(d, a, b, c);
Assert.AreEqual(abcd, bcda);
Assert.AreEqual(abcd, cdab);
Assert.AreEqual(abcd, dabc);
}
/// <summary>
/// Splits all the edges of each face, and connects each of the new vertices together
/// </summary>
/// <param name="m">The m.</param>
/// <returns></returns>
public static Mesh SubdivideInvertedFace(Mesh m)
{
var edges = new HashSet<HalfEdge>(m.HalfEdges.Where(a => a.Primary));
foreach (var edge in edges)
edge.Split(edge.End.Position * 0.5f + edge.Twin.End.Position * 0.5f);
var faces = m.Faces.ToArray();
List<HalfEdge> faceEdgesNewVertices = new List<HalfEdge>();
Queue<Vertex> outerTriangles = new Queue<Vertex>();
foreach (var face in faces)
{
faceEdgesNewVertices.Clear();
outerTriangles.Clear();
//when edges are split, the original edge is left pointing at the new vertex inserted in the middle
//build a list of all the original edges in this face, which means the end vertices of these edges are the new vertices
foreach (var edge in face.Edges)
{
if (edges.Contains(edge)) //this edge ends in a new vertex
faceEdgesNewVertices.Add(edge);
else //this edge ends in an old vertex, find the next and previous vertex and queue them up to become a triangle
{
outerTriangles.Enqueue(edge.End);
outerTriangles.Enqueue(edge.Next.End);
outerTriangles.Enqueue(edge.Twin.End);
}
}
if (outerTriangles.Count % 3 != 0)
throw new InvalidOperationException("Queue length not divisible by three, not possible to construct triangles from this!");
face.Delete();
var central = m.GetFace(faceEdgesNewVertices.Select(e => e.End));
while (outerTriangles.Count > 0)
{
var a = outerTriangles.Dequeue();
var b = outerTriangles.Dequeue();
var c = outerTriangles.Dequeue();
m.GetFace(a, b, c);
}
}
throw new NotImplementedException();
}
public void FacesEnumerator()
{
Mesh m = new Mesh();
var a = m.GetVertex(new Vector3(1, 0, 0));
var abp = m.GetVertex(new Vector3(0, 1, 0));
var b = m.GetVertex(new Vector3(2, 0, 0));
var bcp = m.GetVertex(new Vector3(0, 2, 0));
var c = m.GetVertex(new Vector3(3, 0, 0));
var cap = m.GetVertex(new Vector3(0, 3, 0));
var f = m.GetFace(a, b, c);
var ab = m.GetFace(a, abp, b);
var bc = m.GetFace(b, bcp, c);
var ca = m.GetFace(c, cap, a);
var faces = f.Neighbours.ToArray();
var abc = faces[0] == ab && faces[1] == bc && faces[2] == ca;
var bca = faces[1] == ab && faces[2] == bc && faces[0] == ca;
var cab = faces[2] == ab && faces[0] == bc && faces[1] == ca;
Assert.IsTrue(abc ^ bca ^ cab);
}
public void EdgesEnumerator()
{
Mesh m = new Mesh();
var a = m.GetVertex(new Vector3(1, 0, 0));
var b = m.GetVertex(new Vector3(2, 0, 0));
var c = m.GetVertex(new Vector3(3, 0, 0));
var f = m.GetFace(a, b, c);
var edges = f.Edges.ToArray();
var abc = m.GetEdge(a, b) == edges[0] && m.GetEdge(b, c) == edges[1] && m.GetEdge(c, a) == edges[2];
var bca = m.GetEdge(a, b) == edges[1] && m.GetEdge(b, c) == edges[2] && m.GetEdge(c, a) == edges[0];
var cab = m.GetEdge(a, b) == edges[2] && m.GetEdge(b, c) == edges[0] && m.GetEdge(c, a) == edges[1];
Assert.IsTrue(abc ^ bca ^ cab);
}
public void SplitHalfEdgeOnASingleFace()
{
Mesh m = new Mesh();
var a = m.GetVertex(new Vector3(1, 0, 0), "a");
var b = m.GetVertex(new Vector3(2, 0, 0), "b");
var c = m.GetVertex(new Vector3(3, 0, 0), "c");
var f = m.GetFace(a, b, c);
var mid = m.GetVertex(new Vector3(4, 0, 0), "mid");
var ab = m.GetEdge(a, b);
ab.Split(mid);
Assert.AreEqual(4, f.Edges.Count());
Assert.AreEqual(4, f.Vertices.Count());
Assert.AreEqual(0, f.Neighbours.Count());
var ba = m.GetEdge(b, a);
Assert.IsNull(ba.Face);
Assert.IsNull(ba.Next);
}
public void VerticesEnumerator()
{
Mesh m = new Mesh();
var a = m.GetVertex(new Vector3(1, 0, 0));
var b = m.GetVertex(new Vector3(2, 0, 0));
var c = m.GetVertex(new Vector3(3, 0, 0));
var f = m.GetFace(a, b, c);
var vertices = f.Vertices.ToArray();
var abc = vertices[0] == a && vertices[1] == b && vertices[2] == c;
var bca = vertices[1] == a && vertices[2] == b && vertices[0] == c;
var cab = vertices[2] == a && vertices[0] == b && vertices[1] == c;
Assert.IsTrue(abc ^ bca ^ cab);
}
public void SplitHalfEdgeBetweenTwoFaces()
{
Mesh m = new Mesh();
var a = m.GetVertex(new Vector3(1, 0, 0), "a");
var b = m.GetVertex(new Vector3(2, 0, 0), "b");
var c = m.GetVertex(new Vector3(3, 0, 0), "c");
var d = m.GetVertex(new Vector3(4, 0, 0), "d");
Face abc = m.GetFace(a, b, c);
Face bcd = m.GetFace(c, b, d);
var bc = m.GetEdge(b, c);
bc.Split(m.GetVertex(new Vector3(5, 0, 0), "m"));
foreach (var face in m.Faces)
{
foreach (var edge in face.Edges)
Assert.AreEqual(edge.End, edge.Next.Twin.End);
}
Assert.AreEqual(4, abc.Edges.Count());
Assert.AreEqual(1, abc.Neighbours.Count());
Assert.AreEqual(4, abc.Vertices.Count());
Assert.AreEqual(4, bcd.Edges.Count());
Assert.AreEqual(1, bcd.Neighbours.Count());
Assert.AreEqual(4, bcd.Vertices.Count());
}
public override void Undo(Mesh mesh, Stack<Change> changes)
{
var f = mesh.GetFace(Border.Select(a => mesh.GetVertex(a)));
}
public override void Undo(Mesh mesh, Stack<Change> changes)
{
mesh.GetFace(Border).Delete();
}
/// <summary>
/// Construct a cuboid graph on the given vertices, winding around { top1, top2, top3, top4 } and then all neighbours accordingly
/// </summary>
/// <param name="top1"></param>
/// <param name="top2"></param>
/// <param name="top3"></param>
/// <param name="top4"></param>
/// <param name="bottom1"></param>
/// <param name="bottom2"></param>
/// <param name="bottom3"></param>
/// <param name="bottom4"></param>
/// <param name="factory"></param>
/// <returns></returns>
public static Mesh Cuboid(Vector3 top1, Vector3 top2, Vector3 top3, Vector3 top4, Vector3 bottom1, Vector3 bottom2, Vector3 bottom3, Vector3 bottom4, Mesh m = null)
{
m = m ?? new Mesh();
Vertex t1 = m.GetVertex(top1);
Vertex t2 = m.GetVertex(top2);
Vertex t3 = m.GetVertex(top3);
Vertex t4 = m.GetVertex(top4);
Vertex b5 = m.GetVertex(bottom1);
Vertex b6 = m.GetVertex(bottom2);
Vertex b7 = m.GetVertex(bottom3);
Vertex b8 = m.GetVertex(bottom4);
Face t1234 = m.GetFace(t4, t3, t2, t1);
Face t21b56 = m.GetFace(b6, b5, t1, t2);
Face t32b67 = m.GetFace(b7, b6, t2, t3);
Face t43b78 = m.GetFace(b8, b7, t3, t4);
Face t14b85 = m.GetFace(b5, b8, t4, t1);
Face b6587 = m.GetFace(b7, b8, b5, b6);
return m;
}
public static Mesh Icosahedron(Mesh m = null)
{
m = m ?? new Mesh();
var vertices = icosahedronVertices.Select((a, i) => m.GetVertex(a, i.ToString())).ToArray();
for (int i = 0; i < icosahedronIndices.Length; i += 3)
{
var a = vertices[icosahedronIndices[i + 2]];
var b = vertices[icosahedronIndices[i + 1]];
var c = vertices[icosahedronIndices[i]];
Face f = m.GetFace(a, b, c);
}
return m;
}
public static Mesh Cylinder(int segments, int slices, float radius, float height, Mesh m = null)
{
if (slices < 2)
throw new ArgumentException("Must be more than 2 slices");
height /= 2f;
m = m ?? new Mesh();
Vertex[][] sliceVerts = new Vertex[slices][];
for (int i = 0; i < slices; i++)
sliceVerts[i] = new Vertex[segments];
float angle = 0;
float step = MathHelper.TwoPi / (float)segments;
for (int segment = 0; segment < segments; segment++)
{
Vector2 xy = new Vector2((float)Math.Sin(angle), (float)Math.Cos(angle));
for (int slice = 0; slice < slices; slice++)
{
float l = slice / (float)slices;
float z = MathHelper.Lerp(-height, height, l);
sliceVerts[slice][segment] = m.GetVertex(new Vector3(xy, z), "slice:" + slice + " seg:" + segment);
}
angle += step;
}
m.GetFace(sliceVerts[0].Reverse());
m.GetFace(sliceVerts[slices - 1]);
for (int segment = 0; segment < segments; segment++)
{
for (int slice = 0; slice < slices - 1; slice++)
{
m.GetFace(
sliceVerts[slice][segment],
sliceVerts[slice][(segment + 1) % segments],
sliceVerts[slice + 1][(segment + 1) % segments],
sliceVerts[slice + 1][segment]
);
}
}
return m;
}
public void InsertMidpoint()
{
Mesh m = new Mesh();
var a = m.GetVertex(new Vector3(1, 0, 0));
var b = m.GetVertex(new Vector3(2, 0, 0));
var c = m.GetVertex(new Vector3(3, 0, 0));
var f = m.GetFace(a, b, c);
f.InsertMidpoint(m.GetVertex(new Vector3(4, 0, 0)));
Assert.AreEqual(3, m.Faces.Count());
}
public void SplitEdgeCheckUpdatedIndices()
{
Mesh m = new Mesh();
var a = m.GetVertex(new Vector3(1, 0, 0), "a");
var b = m.GetVertex(new Vector3(2, 0, 0), "b");
var c = m.GetVertex(new Vector3(3, 0, 0), "c");
var d = m.GetVertex(new Vector3(4, 0, 0), "d");
Face abc = m.GetFace(a, b, c);
Face bcd = m.GetFace(c, b, d);
var bc = m.GetEdge(b, c);
var mid = m.GetVertex(new Vector3(5, 0, 0), "m");
bc.Split(mid);
Assert.AreEqual(2, mid.Neighbours.Count());
Assert.IsTrue(mid.Neighbours.Contains(abc));
Assert.IsTrue(mid.Neighbours.Contains(bcd));
}
