public DMesh3 CreateMesh(List <Vector3d> path,
List <Polygon2d> polys,
VectorArray3d seam)
{
// Ignore first and last path/polys for mesh generation.
// We just need the extra path positions to calculate a
// continuous tangent at the seams.
List <Vector3d> pathXZ = new List <Vector3d>();
for (int i = 0; i < path.Count; i++)
{
pathXZ.Add(new Vector3d(path[i].x, 0, path[i].z));
}
int nVerts = path.Count - 2;
int nPolys = polys.Count - 2;
// Same VertexCount for all Polygons.
int nSlices = polys[0].VertexCount;
int nPolySize = nSlices + 1;
int nVecs = nVerts * nPolySize;
vertices = new VectorArray3d(nVecs);
normals = new VectorArray3f(nVecs);
uv = new VectorArray2f(nVecs);
int quad_strips = nVerts - 1;
int nSpanTris = quad_strips * (2 * nSlices);
triangles = new IndexArray3i(nSpanTris);
Frame3f fCur = new Frame3f(frame);
double pathLength = CurveUtils.ArcLength(path.GetRange(1, nVerts));
double accum_path_u = 0;
for (int ri = 0; ri < nPolys; ++ri)
{
int si = ri + 1; // actual path/polys index for mesh
Vector3d tangent = CurveUtils.GetTangent(pathXZ, si);
fCur.Origin = (Vector3f)path[si];
fCur.AlignAxis(2, (Vector3f)tangent);
int nStartR = ri * nPolySize;
double accum_ring_v = 0;
bool copy = ri == nPolys - 1;
bool paste = ri == 0;
for (int j = 0; j < nPolySize; ++j)
{
int k = nStartR + j;
Vector2d pv = polys[si].Vertices[j % nSlices];
Vector2d pvNext = polys[si].Vertices[(j + 1) % nSlices];
Vector3d v = fCur.FromPlaneUV((Vector2f)pv, 2);
vertices[k] = v;
Vector3f n = (Vector3f)(v - fCur.Origin).Normalized;
normals[k] = n;
uv[k] = new Vector2f(accum_path_u, accum_ring_v);
accum_ring_v += (pv.Distance(pvNext) / polys[si].ArcLength);
if (copy)
{
Seam[j] = vertices[k];
}
else if (paste)
{
vertices[k] = seam[j];
}
}
double d = path[si].Distance(path[si + 1]);
accum_path_u += d / pathLength;
}
int nStop = nVerts - 1;
int ti = 0;
for (int ri = 0; ri < nStop; ++ri)
{
int r0 = ri * nPolySize;
int r1 = r0 + nPolySize;
for (int k = 0; k < nPolySize - 1; ++k)
{
triangles.Set(ti++, r0 + k, r0 + k + 1, r1 + k + 1, Clockwise);
triangles.Set(ti++, r0 + k, r1 + k + 1, r1 + k, Clockwise);
}
}
return(MakeDMesh());
}
override public void Generate()
{
if (Polygon == null)
{
Polygon = Polygon2d.MakeCircle(1.0f, 8);
}
int Slices = Polygon.VertexCount;
int nRings = Vertices.Count;
int nRingSize = (NoSharedVertices) ? Slices + 1 : Slices;
int nCapVertices = (NoSharedVertices) ? Slices + 1 : 1;
if (Capped == false)
{
nCapVertices = 0;
}
vertices = new VectorArray3d(nRings * nRingSize + 2 * nCapVertices);
uv = new VectorArray2f(vertices.Count);
normals = new VectorArray3f(vertices.Count);
int nSpanTris = (Vertices.Count - 1) * (2 * Slices);
int nCapTris = (Capped) ? 2 * Slices : 0;
triangles = new IndexArray3i(nSpanTris + nCapTris);
Frame3f fCur = new Frame3f(Frame);
Vector3D dv = CurveUtils.GetTangent(Vertices, 0);;
fCur.Origin = (Vector3F)Vertices[0];
fCur.AlignAxis(2, (Vector3F)dv);
Frame3f fStart = new Frame3f(fCur);
// generate tube
for (int ri = 0; ri < nRings; ++ri)
{
// propagate frame
if (ri != 0)
{
Vector3D tan = CurveUtils.GetTangent(Vertices, ri);
fCur.Origin = (Vector3F)Vertices[ri];
if (ri == 11)
{
dv = tan;
}
fCur.AlignAxis(2, (Vector3F)tan);
}
float uv_along = (float)ri / (float)(nRings - 1);
// generate vertices
int nStartR = ri * nRingSize;
for (int j = 0; j < nRingSize; ++j)
{
float uv_around = (float)j / (float)(nRings);
int k = nStartR + j;
Vector2D pv = Polygon.Vertices[j % Slices];
Vector3D v = fCur.FromFrameP((Vector2F)pv, 2);
vertices[k] = v;
uv[k] = new Vector2F(uv_along, uv_around);
Vector3F n = (Vector3F)(v - fCur.Origin).Normalized;
normals[k] = n;
}
}
// generate triangles
int ti = 0;
for (int ri = 0; ri < nRings - 1; ++ri)
{
int r0 = ri * nRingSize;
int r1 = r0 + nRingSize;
for (int k = 0; k < nRingSize - 1; ++k)
{
triangles.Set(ti++, r0 + k, r0 + k + 1, r1 + k + 1, Clockwise);
triangles.Set(ti++, r0 + k, r1 + k + 1, r1 + k, Clockwise);
}
if (NoSharedVertices == false) // close disc if we went all the way
{
triangles.Set(ti++, r1 - 1, r0, r1, Clockwise);
triangles.Set(ti++, r1 - 1, r1, r1 + nRingSize - 1, Clockwise);
}
}
if (Capped)
{
// add endcap verts
int nBottomC = nRings * nRingSize;
vertices[nBottomC] = fStart.Origin;
uv[nBottomC] = new Vector2F(0.5f, 0.5f);
normals[nBottomC] = -fStart.Z;
startCapCenterIndex = nBottomC;
int nTopC = nBottomC + 1;
vertices[nTopC] = fCur.Origin;
uv[nTopC] = new Vector2F(0.5f, 0.5f);
normals[nTopC] = fCur.Z;
endCapCenterIndex = nTopC;
if (NoSharedVertices)
{
// duplicate first loop and make a fan w/ bottom-center
int nExistingB = 0;
int nStartB = nTopC + 1;
for (int k = 0; k < Slices; ++k)
{
vertices[nStartB + k] = vertices[nExistingB + k];
uv[nStartB + k] = (Vector2F)Polygon.Vertices[k].Normalized;
normals[nStartB + k] = normals[nBottomC];
}
append_disc(Slices, nBottomC, nStartB, true, Clockwise, ref ti);
// duplicate second loop and make fan
int nExistingT = nRingSize * (nRings - 1);
int nStartT = nStartB + Slices;
for (int k = 0; k < Slices; ++k)
{
vertices[nStartT + k] = vertices[nExistingT + k];
uv[nStartT + k] = (Vector2F)Polygon.Vertices[k].Normalized;
normals[nStartT + k] = normals[nTopC];
}
append_disc(Slices, nTopC, nStartT, true, !Clockwise, ref ti);
}
else
{
append_disc(Slices, nBottomC, 0, true, Clockwise, ref ti);
append_disc(Slices, nTopC, nRingSize * (nRings - 1), true, !Clockwise, ref ti);
}
}
}
