public DenseUVMesh UVs; // separate UV layer (just one for now)
// assumption is that # of triangles in this UV mesh is same as in Mesh
public WriteMesh(IMesh mesh, string name = "")
{
Mesh = mesh;
Name = name;
UVs = null;
Materials = null;
TriToMaterialMap = null;
}
// write triangles of mesh with re-ordering to minimize group changes
// (note: this may mean lots of material changes, depending on mesh...)
void write_triangles_bygroup(TextWriter writer, IMesh mesh, int[] mapV, DenseUVMesh uvSet, IIndexMap mapUV, bool bNormals)
{
// This makes N passes over mesh indices, but doesn't use much extra memory.
// would there be a faster way? could construct integer-pointer-list during initial
// scan, this would need O(N) memory but then write is effectively O(N) instead of O(N*k)
bool bUVs = (mapUV != null);
HashSet <int> vGroups = new HashSet <int>();
foreach (int ti in mesh.TriangleIndices())
{
vGroups.Add(mesh.GetTriangleGroup(ti));
}
List <int> sortedGroups = new List <int>(vGroups);
sortedGroups.Sort();
foreach (int g in sortedGroups)
{
string group_name = GroupNamePrefix;
if (GroupNameF != null)
{
group_name = GroupNameF(g);
}
else
{
group_name = string.Format("{0}{1}", GroupNamePrefix, g);
}
writer.WriteLine("g " + group_name);
foreach (int ti in mesh.TriangleIndices())
{
if (mesh.GetTriangleGroup(ti) != g)
{
continue;
}
Index3i t = mesh.GetTriangle(ti);
t[0] = mapV[t[0]];
t[1] = mapV[t[1]];
t[2] = mapV[t[2]];
if (bUVs)
{
Index3i tuv = (uvSet != null) ? uvSet.TriangleUVs[ti] : t;
tuv[0] = mapUV[tuv[0]];
tuv[1] = mapUV[tuv[1]];
tuv[2] = mapUV[tuv[2]];
write_tri(writer, ref t, bNormals, true, ref tuv);
}
else
{
write_tri(writer, ref t, bNormals, false, ref t);
}
}
}
}
public IOWriteResult Write(TextWriter writer, List <WriteMesh> vMeshes, WriteOptions options)
{
if (options.groupNamePrefix != null)
{
GroupNamePrefix = options.groupNamePrefix;
}
if (options.GroupNameF != null)
{
GroupNameF = options.GroupNameF;
}
int nAccumCountV = 1; // OBJ indices always start at 1
int nAccumCountUV = 1;
// collect materials
string sMaterialLib = "";
int nHaveMaterials = 0;
if (options.bWriteMaterials && options.MaterialFilePath.Length > 0)
{
List <GenericMaterial> vMaterials = MeshIOUtil.FindUniqueMaterialList(vMeshes);
IOWriteResult ok = write_materials(vMaterials, options);
if (ok.code == IOCode.Ok)
{
sMaterialLib = Path.GetFileName(options.MaterialFilePath);
nHaveMaterials = vMeshes.Count;
}
}
if (options.AsciiHeaderFunc != null)
{
writer.WriteLine(options.AsciiHeaderFunc());
}
if (sMaterialLib != "")
{
writer.WriteLine("mtllib {0}", sMaterialLib);
}
for (int mi = 0; mi < vMeshes.Count; ++mi)
{
IMesh mesh = vMeshes[mi].Mesh;
if (options.ProgressFunc != null)
{
options.ProgressFunc(mi, vMeshes.Count - 1);
}
bool bVtxColors = options.bPerVertexColors && mesh.HasVertexColors;
bool bNormals = options.bPerVertexNormals && mesh.HasVertexNormals;
// use separate UV set if we have it, otherwise write per-vertex UVs if we have those
bool bVtxUVs = options.bPerVertexUVs && mesh.HasVertexUVs;
if (vMeshes[mi].UVs != null)
{
bVtxUVs = false;
}
int[] mapV = new int[mesh.MaxVertexID];
// write vertices for this mesh
foreach (int vi in mesh.VertexIndices())
{
mapV[vi] = nAccumCountV++;
Vector3d v = mesh.GetVertex(vi);
if (bVtxColors)
{
Vector3d c = mesh.GetVertexColor(vi);
writer.WriteLine("v {0} {1} {2} {3:F8} {4:F8} {5:F8}", v[0], v[1], v[2], c[0], c[1], c[2]);
}
else
{
writer.WriteLine("v {0} {1} {2}", v[0], v[1], v[2]);
}
if (bNormals)
{
Vector3d n = mesh.GetVertexNormal(vi);
writer.WriteLine("vn {0:F10} {1:F10} {2:F10}", n[0], n[1], n[2]);
}
if (bVtxUVs)
{
Vector2f uv = mesh.GetVertexUV(vi);
writer.WriteLine("vt {0:F10} {1:F10}", uv.x, uv.y);
}
}
// write independent UVs for this mesh, if we have them
IIndexMap mapUV = (bVtxUVs) ? new IdentityIndexMap() : null;
DenseUVMesh uvSet = null;
if (vMeshes[mi].UVs != null)
{
uvSet = vMeshes[mi].UVs;
int nUV = uvSet.UVs.Length;
IndexMap fullMap = new IndexMap(false, nUV); // [TODO] do we really need a map here? is just integer shift, no?
for (int ui = 0; ui < nUV; ++ui)
{
writer.WriteLine("vt {0:F8} {1:F8}", uvSet.UVs[ui].x, uvSet.UVs[ui].y);
fullMap[ui] = nAccumCountUV++;
}
mapUV = fullMap;
}
// check if we need to write usemtl lines for this mesh
bool bWriteMaterials = nHaveMaterials > 0 &&
vMeshes[mi].TriToMaterialMap != null &&
vMeshes[mi].Materials != null;
// various ways we can write triangles to minimize state changes...
// [TODO] support writing materials when mesh has groups!!
if (options.bWriteGroups && mesh.HasTriangleGroups)
{
write_triangles_bygroup(writer, mesh, mapV, uvSet, mapUV, bNormals);
}
else
{
write_triangles_flat(writer, vMeshes[mi], mapV, uvSet, mapUV, bNormals, bWriteMaterials);
}
}
return(new IOWriteResult(IOCode.Ok, ""));
}
// sequential write of input mesh triangles. preserves triangle IDs up to constant shift.
void write_triangles_flat(TextWriter writer, WriteMesh write_mesh, int[] mapV, DenseUVMesh uvSet, IIndexMap mapUV, bool bNormals, bool bMaterials)
{
bool bUVs = (mapUV != null);
int cur_material = -1;
IMesh mesh = write_mesh.Mesh;
foreach (int ti in mesh.TriangleIndices())
{
if (bMaterials)
{
set_current_material(writer, ti, write_mesh, ref cur_material);
}
Index3i t = mesh.GetTriangle(ti);
t[0] = mapV[t[0]];
t[1] = mapV[t[1]];
t[2] = mapV[t[2]];
if (bUVs)
{
Index3i tuv = (uvSet != null) ? uvSet.TriangleUVs[ti] : t;
tuv[0] = mapUV[tuv[0]];
tuv[1] = mapUV[tuv[1]];
tuv[2] = mapUV[tuv[2]];
write_tri(writer, ref t, bNormals, true, ref tuv);
}
else
{
write_tri(writer, ref t, bNormals, false, ref t);
}
}
}