Mesh color data

Replies to This Discussion

Permalink Reply by Andrew Heumann on June 15, 2015 at 5:06pm

Yes, this should be possible. Do I understand that your mesh already has appropriate mesh texture vertices assigned to it? It would be great if you could upload your file. The following script works for my example - but it also assumes that your mesh vertex texture coordinates all fall within the domain {0,0} to {1,1}. If you upload your file we can try to come up with something more tuned to this particular scenario. 

private void RunScript(Mesh mesh, string imagePath, ref object A)
{
mesh.VertexColors.Clear(); //in case there's existing mesh vertex colors assigned
//mesh.TextureCoordinates.NormalizeTextureCoordinates(); //uncomment if your texture coordinates need to be renormalized
Bitmap bmp = new Bitmap(imagePath);
for(int i = 0;i < mesh.Vertices.Count;i++){
Point2f coord = mesh.TextureCoordinates[i];
int xVal = (int) (bmp.Width * coord.X);
if(xVal >= bmp.Width) xVal = bmp.Width - 1;
if(xVal < 0) xVal = 0;
int yVal = (int) (bmp.Height * coord.Y);
yVal = bmp.Height - yVal;
if(yVal >= bmp.Height) yVal = bmp.Height - 1;
if(yVal < 0) yVal = 0;
Color c = bmp.GetPixel(xVal, yVal);
mesh.VertexColors.Add(c);
}
A = mesh;
}

Permalink Reply by Daniele Profeta on August 26, 2015 at 11:11pm

HI Andrew!

This seems exactly what I need. Can you please help me understand how I should use this script? I copied into the C# scriptable component but I cannot seem to make it work. Any help would be extremely appreciated!!

In the long run I am trying to apply this transformation (texture to mesh vertex color) to export a csv file formatted as x,y,x,r,g,b for all the vertices. Hope this makes sense.

Thanks in advance for all your help,

Cheers

Daniele

Permalink Reply by Daniel González Abalde on June 16, 2015 at 4:52am

I think to make a custom mapping from an image like that, the problem is you need to flatten the mesh, making the corresponding points snap into the correct position of the color image. So you use an image and a mesh very little complex, or need to adjust the points moving them by hand, which gh does not allow comfortably.

I have little experience mapping textures in 3DMax, but the texture images (like that) are made after making the flattened mesh (UVW unwrap, if I remember correctly). So if you manage to flatten the mesh (no overlap), make an image of the flat mesh and take it to photoshop, paint over her attending parties, and then in gh you use this color information to paint the flat mesh, and as you have not changed the topology of the mesh, that list of colors will serve to paint the texture on the original mesh.