Help intersecting solids accurately

Hi @Athanasia
First of all, your part has no bottom surface - use cap to fill it. After that, just make a box and use BooleaDifference to create the counter part. When doing booleans on coadjacent surfaces, it’s always a good idea to run MergeAllCoplanarFaces after each boolean to keep thegeometry as simple as possible (in the video I do it after capping the bottom too). A quick video of how I would do it :slight_smile:
HTH, Jakob

ok! Thanks Jacob. I love and hate how easy you make it look. I’m making it all very complicated and time consuming.

I will try it this way. I missed the empty bottom surface. When you extrude a curve and check the solid tab you would think it would be solid.

Thanks

It should be, of course. No idea where it went :slight_smile:
-Jakob

while I have you here… is there a way to move my command line box o the top? I use rhino for mac and find it’s easier to view the command lines on the top like how you have yours layed out.


4

mine:
Screen Shot 2022-04-22 at 10.08.10 AM

i guess not

Command line works quite differently on the mac, so as far I know – you can’t have it on the top like on windows.

You could try: Windows > Floating Panels > Show Command History (from the top menu)

Hi @Athanasia
Sorry - workday was over :grin: And I can’t help you anyway. I’ve never used Rhino for Mac. You could ask in the Mac part of the forum - I’m sure someone will know!
-Jakob

Thanks @Normand
I totally understand. The design in the print was made better the instruction from the video you sent.

Question for you when you get back to office, should boolean subtract always have to have overlapping geometry? I found that when I had it intersecting at the seams it would subtract the wrong parts.

hey! @Normand, I know you may not be working but I didn’t want to start a new thread as it seems to be the same issue. I was wondering if you can help troubleshoot my join and intersect fails.

I seem to get the same problem occurring when I try to join two boxes together. The join command does recognize the surfaces I want to join even though they are aligned in all the positions. I would like to be accurate and efficient, but I am finding when I use boolean union if I m off on my alignment it shows in the model. I’m not sure if it’s bug but my join command at times fails. I have them in the correct position on all view points. This has happen often, am I missing something?

Also when try to intersect command but I am getting ‘0 intersection’, what am I missing?

Here are some pictures.

Hi @Athanasia,
If you look at your screenshot of the join command you will see that it displays the clue “Curves, surfaces, polysurfaces, and SubD’s must be open”. A box is an example of a closed polysurface so join cannot be used with it. To join closed polysurfaces you need to use Boolean Union.

To join an open polysurface with a closed polysurface you need to explode the closed polysurface, remove any resulting duplicate surface portions, then use join to assemble the whole thing. This will result in a new open polysurface.

Note that when you select polysurfaces Rhino will tell you in the command area whether they are open or closed.

HTH
Jeremy