Border edges cannot be made soft in Maya

dharness

I created a mesh from a plane primitive and cannot remove the hard edges on its border (shown in purple) This is causing issues when I try to extrude and use smooth preview. When I bring the model into blender and clear hard edges  I can extrude and apply a subsurf with no issue. However, bringing that same model back into maya (after hard edges are cleared) shows the edges as hard again in Maya.

This is only true of border edges.


 

oglu

Borderedges are hard in a catmull clark subD. And corner verticies create those pinches. If you connect those "flying verticies" you dont have the pinching issue. And i assume there are inverted faces on the bottom.

dharness

Thanks oglu - I did have inverted faces. I am still a little confused about these hard edges I am seeing though - for example this cube has all hard-edges which cannot be cleared and do not resist collapsing under subD. I am displaying these purple lines with Display > Polygons > Hard Edges 
So I guess there are 2 issues:
1. What does this actually display?
2. If this is not how to display truly hard edges, then how?

Ghogiel

So selecting all those edges and setting soften edge doesn't remove hard edges?

oglu

SubD does not care about hard edges. Only border edges and corner verticies. If you clean them up with proper modeling you get a smoothed mesh. 

sprunghunt

You can set it to respect hard edges when smoothed. Do this:

1. Select the mesh and go to the shape node
2. Now go to Smooth Mesh - turn off "use global (opensubdiv catmull-clark)" 
3. set the "subdivision method" dropdown to "maya catmull-clark"
4. now go to the "maya-catmull-clark controls" and click on "preserve hard edges"

This is how you get subdiv that uses hard edges like creasing. You can also adjust a few other things here. Have a look at this blog post I made that's also relevant:

https://www.artstation.com/dankeating/blog/dKOZ/quick-script-for-changing-smoothing-values-across-multiple-objects

dharness

Ghogiel said:

So selecting all those edges and setting soften edge doesn't remove hard edges?

Correct! Very odd.

Thanks for the info!

oglu

Maybe those edges are locked? Use unlock and then smooth. 

And BorderEdges cant be soft.