subdivide on manifold surface

[EdHa]

On some surfaces I can apply subdivide (for T-spline manipulation) and on some I get the error: subdivide operationon can be applied only on manifold surfaces.

What is a manifold surface?

[AndrewSears · Accepted solution]

Edward,

When we say the part needs to be a manifold part, it means that somewhere on your model you have 1 edge touching more than 2 surfaces.

Here is an example: This part comes to a point an edge at the blue highlight.  1 edge touches 4 surfaces.  This is a non-manifold part.

If this does not help, add me to your hub using andrew.sears@autodesk.com and I will take a look at the file and let you know.

Thanks,

Andy 

[dcgall]

I'm having the same issue but my TSpline does not appear to have the same problem as your screen shot example.  Please see my screen shot.  

I sculpted an object and because of some bad geometry, I removed some faces.  I'm hoping that I can create faces to once again make my TSpline a "solid".  I was then going to rely on subdividing to further modify my TS, but I'm running into the same subdivision error.  The face I've selected appear to touch only those faces around it - not having the same situation that you say causes this error. ???