Question About Shape Keys and Subsurface Modifiers

In a tutorial for Blender 2.55, the presenter said that Shape Keys and non-applied Subsurface modifiers don’t mix well, that the resulting animation could be unpredictable.

However, I did a few tests, some with armatures, others with shape keys, and the resulting rendered animations seem to be exactly what I expected.

So, my question is:

Has this restriction (don’t mix shape keys with non-applied subsurface modifiers) been changed in recent releases?

I checked the release notes and the wiki, but didn’t see any mention of this.

I’ve never had an issue with using SubSurf on shape-keyed meshes, including those made for meshes that are also under armature control (corrective shapes). Not sure why that was flagged as a problem. Have you a link to the tutorial?

Here’s the tutorial: http://www.youtube.com/watch?v=WXiHdqw4B1w

If you ‘fast forward’ to 2:29, that’s where he mentions this.

I’m gearing up to rig and do shape keys for a number of characters, so knowing ahead of time is very helpful.

Thanks for the reply, chipmasque. I’m really curious to know if I just misunderstood him.

I think he mistakenly includes SubSurf in this statement. The point being made is that the topology and in particular the vertex count of a mesh should be final before adding shape keys, so any mesh editing operations (subdivision, extrusion, etc.) that change this on the base mesh will break any previously-made shape keys. But the Subsurf modifier (un-applied) does not change vertex count on the base mesh, so it shouldn’t present any issues. It’s only after the SubSurf modifier has been applied that the vertex count will actually change, so for meshes with shapes, it’s better to leave the modifier on the stack.

Thanks, chipmasque.