Hi Michael,

I attached two files, the original inhalator before making the grooves and a test file that I used to see whether my problem was related to the complexity of the shape. In both cases the boolean between the "tube" and the base object does not result in the result I expected. I am curious if I made a mistake.

Yours sincerely,


Ray Deleu

Very design!
Added to the Special thread Gallery :)

Hi Ray - one thing is the outer surface of your inhaler-2n1.3dm file is duplicated - I mean if you select it and drag it away you can see there is another copy of it underneath.

I've seen duplicated surfaces like these a few times now and I think there may be a bug in something that generates them. If you have any idea of what might have caused this duplicate please let me know.

Other than that, it looks like you may be running into a problem where the boolean operations don't quite work as expected right now when one of the objects involved is an open surface instead of a closed solid.

You may need to use the Edit/Trim command instead of booleans when working with open surfaces.

So in this case, select the outside surface and the "groove tube". Run Edit/Trim, and at the "Select cutting objects prompt", just push "Done" - this signals that you are going to do a "mutual trim" operation where the selected objects are cutting each other. Then at the next prompt just push "Done" to leave all the pieces behind (since in this case some of the pieces are kind of obscured).

Then you can select and delete the half of the tube and the little strip of the outer surface, leaving you with your groove:

You can then use join to glue these pieces together.


> I am curious if I made a mistake.

I don't think so... I think maybe you got hit with the booleans-with-non-solid issue that is present right now.

Please let me know if you need any more details or if I have misunderstood anything.

- Michael

Just quicky try without any precision (just for the concept) but maybe that could be work :)

With more attention to the orientation and size of circles )
In fact that is not a verygood idea :D

Just a little question : When an arc is "extended" to a boundary object : it's an always an arc or a certain tangent line from the existant arc toward the boundary object?

Ps Very sinuous grooves Michael and tricky tip ! :)

Hello Michael,

Thanks for your reply. I think I understand your method but will try later today to see it for myself.

Originally the outer shell of my inhaler was closed. However, after the sinusoidal cut and bevel (rounding) I deleted the side surfaces were the inner part of the inhaler is located. Perhaps the boolean method would have worked if I had applied it earlier in my modelling process. I will try to remember to do booleans preferably with closed surfaces.

I can imagine that the double surfaces were created in the modelling process as sometimes I did not understand exactly what happened during a trim or boolean.

Yours sincerely,

Ray Deleu.

I added two renders of objects created with MoI, rendered with C4D 6+.

> I think I understand your method but will try later today to see it for myself.

Sounds good, please let me know if it doesn't seem to work right.


> I can imagine that the double surfaces were created in the modelling
> process as sometimes I did not understand exactly what happened
> during a trim or boolean.

I think that something may be duplicating things in an unexpected way. Anyway, if you happen to notice this happening during a modeling session, please let me know.


> I added two renders of objects created with MoI, rendered with C4D 6+.

Looks groovy! :)

- Michael

Other than that, it looks like you may be running into a problem where the boolean operations don't quite work as expected right now when one of the objects involved is an open surface instead of a closed solid.

Yes, I can confirm this. I was trying to make a threaded screw. I swept a circle along a spiral curve, then tried to subtract it from a cylinder. But, when I tried to do the boolean, it didnt work. I looked at the ends of my sweep, and they where open. I selected the ends and closed them with 'planar'..then the boolean worked perfectly.