# Pockmarks on tapered column

I’m attempting to populate a piece of tapered geometry (a column) with a pattern of circular pockmarks but I am running into difficulties. I thought I might be able to surface morph circles, extrude those circles, and Boolean subtract from the larger geometry, but I have been unsuccessful thus far. Any suggestions for how to better approach the problem would be great appreciated!

I am also working to extrude (outward) a half-circle “lid” from above each circle. I can surface morph the curves onto the column but do not know how to extrude them.

COLUMN1_A.gh (34.2 KB)

As you’ve noticed, boolean difference won’t work if your extrusions aren’t closed breps…
or maybe they will? Who knows gh is strange…

Plus, I wouldn’t immediately go to booleans since…slowness…

…and even if you don’t use solid difference there might still be some slowness with this type of operation because of splitting and joining and capping and all that.

Furthermore, using curve-mapping as you have will inevitably make your original planar curves non-planar.

If you use orient as an alternative, you have it a bit easier, but you can also use brute-force. Both options looked at below:
COLUMN1_A.gh (55.0 KB)

NOTE: sorry didn’t do anything about your half-circle ‘lids’, but you should be fine

(edit)
fast gives you flat insides:

slow gives you non-flat insides (if it matters):

Best

Here is one of many possible solutions for half-circles.

As @_corellaman mentioned you have to take care of planarity for closing breps…

COLUMN1_A_RE.gh (35.7 KB)

Thank you, @_corellaman! Orient works beautifully - this is extremely helpful.

Thank you @Jakinta - greatly appreciated