public static void GenerateRingMesh(
List <Vector3> ring, MeshPart part, Vector3 normal, bool side, Vector2?innerUV, bool addNormals = false
)
{
bool addUVs = innerUV != null;
// List<List<Vector3>> reduceHist = new List<List<Vector3>>();
// reduceHist.Add(ring);
int indStart = part.vertices.Count;
part.vertices.AddRange(ring);
if (addUVs || addNormals)
{
foreach (var _ in ring)
{
if (addUVs)
{
part.uvs.Add(innerUV.Value);
}
if (addNormals)
{
part.normals.Add(side ? -normal : normal);
}
}
}
List <Tuple <Vector3, int> > set = ring.ConvertAll(v => new Tuple <Vector3, int>(v, indStart++));
int i = -1, lsc = set.Count;
bool didInf = false;
while (set.Count > 1)
{
i++;
if (i >= set.Count)
{
if (lsc == set.Count)
{
if (didInf)
{
// Debug.LogError("ear clipping failed");
// DebugRings(reduceHist);
// Debug.Log("normal "+(normal*1000));
// DebugRing(set.ConvertAll(s=>s.Item1));
throw MeshUtilsException.Internal("Ear clipping failed");
}
didInf = true;
}
else
{
didInf = false;
}
lsc = set.Count;
}
i %= set.Count;
Tuple <Vector3, int> vi0 = set[i],
vi1 = set[(i + 1) % set.Count],
vi2 = set[(i + 2) % set.Count];
Vector3 d1 = vi1.Item1 - vi0.Item1; // i0 -> i1
Vector3 d2 = vi2.Item1 - vi0.Item1; // i0 -> i2
// we assume points do not lie in a line (see SimplifyRing)
// if they do however, it's just a waste of vertices
// check convex ear
float conv = Vector3.Dot(Vector3.Cross(d1.normalized, d2.normalized), normal);
if (conv > 0)
{
continue;
}
// check that there are no other vertices inside this triangle
if (set.Exists(v => {
// note: we must compare the vectors, otherwise coinciding vectors do not
// register as being the same
if (v.Item1 == vi0.Item1 || v.Item1 == vi1.Item1 || v.Item1 == vi2.Item1)
{
return(false);
}
return(VectorUtil.CheckIsInside(d1, d2, v.Item1 - vi0.Item1));
}))
{
continue;
}
// generate indices
if (side)
{
part.indices.Add(vi0.Item2);
part.indices.Add(vi1.Item2);
part.indices.Add(vi2.Item2);
}
else
{
part.indices.Add(vi0.Item2);
part.indices.Add(vi2.Item2);
part.indices.Add(vi1.Item2);
}
// eliminate vertex
set.RemoveAt((++i) % set.Count);
i++;
// reduceHist.Add(set.ConvertAll(s=>s.Item1));
}
}
