How to cut a very large hole in a multi-layer grouped wall

Tube RH 14 .skp (223.9 KB)

The architect who designed this 2D project made it so that some walls have to open up to other structures. I also have to cut away most of the bottom so that I can have the floor plan beneath it and draw the walls, etc. in 3D.

In the past I have been able to cut out a rectangle in the floor from below. This time it will not work.

How can I cut holes in the walls of this tube?


I made an animated GIF of my problem. You can find it here: .

You haven’t opened the group for editing which is why you can’t remove the floor and also why you are getting the Z-fighting.

As I showed you before, you have to open the group for editing to modify the geometry within the group.

I’m confused. If I double-click on a group with the Select tool, doesn’t that open the group for editing? And, doesn’t the dotted line around the group in my screenshot indicate that it has been opened for editing?

I’m double clicking again and I can’t isolate the portion within the rectangle I’ve drawn.

I made a new animated GIF to illustrate what is happening: .

Thank you for your anticipated reply.


Upload the .skp file.

You have in the past had nested groups in your model. Double clicking with Select on the group opens it for editing but if there’s a group inside it, then you still aren’t into the geometry and would end up with Z-fighting when you draw the rectangle.

Tube RH 14 .skp (226.6 KB)
Dave, So, how do I figure out whether or not there is another group inside the group? What steps should I take then?


Look at Outliner. It will show you that.

You have a group inside a group inside a group.

Another way to figure it out is open the group for editing and try to select a single face. If you get a blue boundiing box, you’ve selected a group. When you finally get inside you should be able to select the face without selecting anything else.

Really there’s no need for any nesting in this model the way you’ve created it.

Leave the colors/materials off the model until you’ve completed the geometry correctly. The materials just make it harder to work on the model.

On the thread you created some days ago someone gave you the link to free courses to learn the program, the basic course covers how to do this kind of things, I’ll post it again here.

Don’t misunderstand me, this community is a very active one and we love to help those who need it, but you could solve this issues and more complex ones by yourself if you take just a few minutes per day or week and try to learn just the basics.