Hello.
I’m developing a modifier to modify the vertex color channel of an object. I already know how to deal with Mesh from TriObject, but I also need the equivalent for MNMesh (PolyObj). Does someone know how to make it correctly?
This is my code for Mesh:
Mesh& mesh = triobj->GetMesh();
int NumVertexColors = mesh.getNumVerts();
BOOL bRes = mesh.setNumVertCol(NumVertexColors);
if (!bRes) return;
const int NumFaces = mesh.getNumFaces();
bRes = mesh.setNumVCFaces(NumFaces);
if (!bRes) return;
VertColor *vertCol = mesh.vertCol; //array of Point3 vertex colors
if (!vertCol) return;
TVFace *vcFace = mesh.vcFace; //texture faces
Face* faces = mesh.faces; //faces of my mesh, to convert texture vert index to the geometry vert index
for (int iFace=0;iFace<NumFaces;++iFace)
{
for (int j=0;j<3;++j)
{
int vertIndex = faces[iFace].v[j];
vcFace[iFace].t[j] = vertIndex; //each texture vertex is assigned to its geom vertex
}
}
this is code i use to set a whole mnmesh vertex colour, IVCmodParams is a data holding class I use. It has two custom function evalcol which computes the colour and blend which uses traditional photoshop blend modes to blend the new colour over the original.
void VCModUtils::TintMesh(MNMesh& pmesh, IVCmodParams& p)
{
AColor c;
// get the vertices & faces in this texture map
MNMap* mnMap = pmesh.M(p.getMapChannel());
int nmapverts = mnMap->numv;
UVVert* mapverts = mnMap->v;
MNMapFace* mapfaces = mnMap->f;
DbgAssert(mapverts);
DbgAssert(mapfaces);
// create a bit array to make sure we only visit a map vert once
BitArray vertset(nmapverts);
// geofaces & verts
int nfaces = pmesh.numf;
MNFace* geofaces = pmesh.f;
MNVert* geoverts = pmesh.v;
// unfortunately we can't do the same pointer trickery here :\
for(int i=0; i < nfaces; ++i)
{
MNFace& geoface = geofaces[i];
MNMapFace& mapface = mapfaces[i];
const int fdeg = geoface.deg;
for(int j = 0; j < fdeg; ++j)
{
int mapvert = mapface.tv[j];
if(!vertset[mapvert]) // have we been here before ?
{
Point3& pos = geoverts[geoface.vtx[j]].p;
p.evalcol(pos, c); // evaluate the colour
p.blend(mapverts[mapvert], c, c.a, mapverts[mapvert]);
vertset.Set(mapvert);
}
}
}
}
I check for map channel support earlier in the code with
int mapChannel = p.getMapChannel();
if(mapChannel >= pmesh.numm || pmesh.M(mapChannel)->GetFlag(MN_DEAD))
DefaultMapping(pmesh, mapChannel);
and this is the code I use a intializing the map… you can use some of the existing routines
void DefaultMapping(MNMesh& pmesh, int mapch)
{
// initialize the map
if(mapch >= pmesh.numm)
pmesh.SetMapNum(mapch+1);
pmesh.InitMap(mapch);
// fill with white
MNMap* map = pmesh.M(mapch);
UVVert* mv = map->v;
int nmapverts = map->numv;
for(int i = 0; i < nmapverts; ++i)
mv[i] = uv_white;
}
Thanks a lot, it works great
there a really useful reference on how to set vert colors/mapping to selected faces e.g hard edges in the samples \Autodesk\3ds Max <version> SDK\maxsdk\samples\modifiers\uvwxform.cpp using a really neat utility class called TvMap which can be used for mesh/mnmesh and patchmesh with either mapping or vertex colors. It’s tough going but worth it.
Hi,
I am trying to set face color (random colors) for the mesh (not editable mesh and not editable poly, its an object mesh filled with details).
I have tried the method mentioned above (for mesh). Additionally, I add this line to set color
after this line,
vcFace[iFace].t[j] = vertIndex;
added this
mesh.setMapVert(1, vertIndex, clr);
but the color changes are not affected, not able to shown in viewport. dont know whether the values are set or not.
Is this the right way to set color ?
Please suggest me.
Regards,
Gopinath
Hello,
I was able to solve this.
Thanks.
Gopinath