i stumbled upon this, what does it mean?

If you take a look at the screen capture below:

You will see that the top face has been subdivided without extra edges being created on the sides of the cube. I selected the face then e to exrude then i changed my mind and hit esc-key. Without removing doubles i selected w-key and sudivided once.

To my supprise the image above was created. Then i removed vertices and the subdivided faces remained. Is this legit ? Can anybody explain why the “normal” extra edges were not created this time.

BTW i’m using the cvs build by gabio.

extrude does things in two steps

the first step extrudes the edges of the region selected, the second step enters grab mode on those verts you had selected

when you hit esc [right clicking does this too] it only cancels grab mode, the extrusion is still there, just it is zero length

Yeah thanks you are right.

hehe I have also ran into these mysterious 5 sided polys a couple of times. it was a real head scratcher. just move some vertices around though, and it becomes clear what’s going on.