Question about extrusion

on video 4 of rhino5 webinar at 22 min. she shows a plane that she say’s split with curves and then joined back together, she then picks the circle and extrudes it down with the gumball to create a cup cake pan…
when I spit a surface like her example and re join it I cannot pick the circle srf and extrude it down for the cupcake dish…if I pick the circle and extrude it down I get a tube but the surface is still on top

Hi Pat- this should work as described if the split face is Joined back into the larger plane.


Thanks Pascal , but still no luck… I made a flat srf, drew a circle, split the srf, the joined circle to srf, and srf to circle…no luck either way I still cannot select the circle to make the cupcake pan when I select I get the whole ‘joined’ srf

Pascal here’s my file …the srf was split, and joined see if you can figure out what I’m doing wrong …thanks cake pan.3dm (101.4 KB)

got it…split srf, shrink yes, join, control / shift will let me select for the ‘cupcake’…