Subtract selection from


Having spent much time selecting points and curves within a group, copying and grouping that selection, I now need to select those I didnt select in that group. How can I use that first selection to select the group less that first selection ?


If you are asking about removing selected items while using a command then press the Control key and select what you want to you want to remove from the selection.

Or are you asking about something else?

No, not whilst I am selecting. I have already selected after much careful mouse work a load of points and some curves which are part of a group of more of the same. Did a transform copy inPlace and grouped the result and moved it out to use.

Now I also need those and only those I didnt select that first time. can I use those I did select to subtract from the group and leave me those I didnt select that first in the group.

lets say I have ABCDEFGHIJ and select ACEG and group it, later I want BDFGHIJ, can I use ACEG to subtract from the group and leave me BDFGHIJ ?


Turn off layers and hide objects so that only ABCDEFGHIJ are visible
Select ACEG

Hi Steve- RemoveFromGroup

e.g. in the scenrio you described, if I understand you, Ctrl-Shift select all the items you want, then run RemoveFromGroup then Group. You’ll now have the original group split into two groups.


Hi, No one is quite getting this.
I started out with a load of points and a few curves for both port and stbd side of an aircraft fin.

I selected them all and grouped them.

A few days later I carry out a careful selection of all those on the port side, then go Modify Copy InPlace and group the result.

I drag that aside and mess around with Patch command and skin it as best I can. (wish patch was a better command)

I now wish to try patch on stbd side. Why mess around for hours I think to myself using Cntrl and shft and mouse clicking trying to select all the points in the original group which occur only on the stbd side when I already have port side selected as a group, maybe I can use this port side group in conjunction with the original group which has both port and stbd points etc, in some kind of subtractive way, to give me the stbd only stuff.

Admittedly I did move aside the port side group but I could move it back dead easy as I used move R0,2000 so R0,-2000 would do that !


You could probably feed both groups to lists in Grasshopper, cull the duplicates and bake the remainder into Rhino… Or someone might have a script around that almost does what you need.


I dont have Grasshopper.
Hope there is a script in that case.

Seems like something that is very simple.

I hope someone drops by and sees this hopefully simple need.


Instead of wishing for commands which don’t exist, try to anticipate how you will want to use your data and create ways to select it that will give you flexibility in the future. For instance, when you decided to separate out just your port side points, you could have made two groups, one of the port side and one of the starboard side. Then group the two groups if you want them to behave as a single group. Now in the future you can ungroup one step to get the two groups and then grab the one you want.

Another approach would be to select all your port side points and change the color to a custom color. Now if you want to remove your port side points later you can use SelColor to select them and RemoveFromGroup.

Or you could put all your port side points on one sub-layer and starboard side points on another. Then you can turn them on or off or use SelLayer.

You just have to think a bit when you set up your file about the different ways you may want to select parts later and build in those pathways. I often use all these methods in combination so I can quickly select by multiple criteria. Say you put all brass screws on one layer, stainless on another, and zinc plated on another. Now make all 1/4" inch screws a shade of teal, 3/8" screws pale orange, 1/2" screws dark green. Now by turning off layers and using SelColor I can select just those screws which are both stainless and 1/2".

i think with rhino in this scenario, it would be best to ungroup A->J first… then select ACEG and group it… then select them all and ctrl-click one of the objects in ACEG… which will leave you with BDFGHIJ selection ready to be grouped…

another way of saying that–
i personally think it’s best if you only work with one level of grouping instead of what you’re looking to do–> manage groups while inside of groups… there isn’t a good way to monitor that in rhino… it’s better to do that type of stuff with layers (in my opinion)

It turns out to be very simple with Grasshopper (which is a simple install of a free plugin). Just 3 components and you’re done…

Now with NamedSelections (New in V7) the critical step would be immediately after making the first, laborious selection, save it to a Named Selection A. Then, isolate AB and create an SelInvert from that and save that selection as B.

Also, the color and layer coding others suggested above will further secure your ability to avoid re-selection work. One can even SelColor. , SelPt or SelSmall or other special Selects to further automate portions of work.

But I agree, there’s basically no better learning than the Hard Way.