Remove doubles not working with different materials?

Hello all,
Former Maya user. I’m having a bit of trouble with welding 3 meshes together. Each mesh is made of a different material.
Green is ground material, yellow is water, and blue is deepwater.
http://img.photobucket.com/albums/v290/korben_dallas/matweld1.jpg

In Object Mode, I do a Select All, Objects > Join Objects. Verified it is one single mesh now.
Then I do a Select All, go to Edit Mode, then Vertices > Remove Doubles. “0 vertices removed”. Even if I crank up the tolerance all the way to 1.0, still nothing.
Here is proof the vertices are right on top of each other.
http://img.photobucket.com/albums/v290/korben_dallas/matweld2.jpg
http://img.photobucket.com/albums/v290/korben_dallas/matweld3.jpg

And now I right click + shift right click + shift right click the three vertices and do a Vertices > Merge > At Center. “2 vertices removed”.
And I verify indeed that now the 3 materials are welded and the single vertice moved around will stretch all of them.
http://img.photobucket.com/albums/v290/korben_dallas/matweld4.jpg

So how come remove doubles isn’t working? :confused:
There is no way I can do this by hand… we’re talking 5000+ doubled verticies. I didn’t have this issue in Maya. Am I doing something wrong?

well, apparently your vertices are more than 1.0 apart. maybe.

without testing it out, just an idea off the top of my head is, if you think it is the fact that they are different materials is preventing rem doubles to work (wierd!), is to select each material group verts and assign them to a vertex group. then make all the materials the same. Do the rem doubles, and then, re-assign back each vertex group to its original material. in other words, use the Vertex Groups as sort of a holding pen.

EDIT: i did one object with 2 verts very close. One vert was one material, the other was a red material. Selecting both and remdbl worked. Assigning multiple materials did not prevent remdouble from removing. so i cannot replicate your problem. As long as both verts that were close were both selected, remdbl did its thing. Maybe with N the properties panel up, select each vertice and see/calculate how many BU they are apart; maybe each of those little squares is a BU, so they really are like two and three BU apart.

Another possibility: It looks to me that the verts in question (pic #2 & #3) aren’t selected…

Then I do a Select All, go to Edit Mode, then Vertices > Remove Doubles. “0 vertices removed”.
if you select all in object mode you are just selecting all objects… you need to select your object, then you need to go to edit mode first and then select all… look in the top header bar and see if all the verts are selected before trying to remove doubles.

I just tried to duplicate your situation and it worked out fine for me. paprmh got a point there, most of the times Remove doubles doesn’t work is because of faulty usage…it happens to me quite often as well (like looking at the verts from a perspective where they seem to be very close together, which is actually not true).

:slight_smile: Thanks alot guys.

Indeed it was the selection. I had to go to Edit mode, and then hit the A key (select all) a couple of times until the whole mesh was Yellow highlight and the (76000 - 76000) verts showed in the info window. Remove doubles did the trick… 3600 verts removed!

Thanx again :smiley: