Isolating areas of a mesh and moving to another layer


I have a sketchup model that has a large area of terrain as a mesh. I am wanting to leave a large area of this terrain untouched but want edit a small area of it to accommodate changes in the terrain and also keep the original terrain of the same area for comparison.

Rather than have two copies of the same big mesh i figure the best way is to isolate the area of the large mesh i want to edit and put on another layer and then edit that and make duplicates of it

Can anyone give me some tips on the best way to select an area of an existing mesh in a group, move it to another layer in such a way that when the smaller area is put on another layer it doesn’t merge with other entities, and are completely independent?



First and foremost, make sure ALL of the edges and faces in the model are on Layer 0. Select the area you want to isolate and make it a group. While the group is selected, copy it with Ctrl+C. Then, while it is still selected, associate the group with your “original terrain” layer. Turn off the visibility for that layer and you should see a gap where it was. Hit Edit>Paste in place to create a new copy of the group. Assign it to the “modified terrain” layer. Edit this version of the group as needed to show the changes. You can then switch between unmodified and modified terrain layers for your various scenes.


Your idea will not work because SketchUp layers do not isolate geometry from interaction. You will need to use groups or components for that. Make a group for the unmodified part of the mesh and another for the modified part and put those on different layers. You will need to be sure that the portion of the mesh you capture in the group exceeds the part that will be affected by your edits else you will get breaks at the boundaries.

Edit: as happens oh so often, @DaveR beat me to it and provided more details…


Dave, thanks for the instruction, and following your advice worked, what is so special about Layer 0?
In the end i copied the terrain to a new sketchup file and did as you discribed in there, before copying back to the original sketchup file


Layer 0 is the default layer. ALL edges and faces should be create on and remain on Layer 0. As Steve said, layers don’t isolate entities as they do in other programs. The only way to isolate geometry is to put it in a group or component. Following the simple rule of leaving Layer 0 active at all times and leaving all geometry on Layer 0 will make your life easier and help to keep you from being packed off to a quilted room.


thanks, i am not very experienced in sketchup, and based on what you have said only groups and components should be put onto separate layers?
The workflow being create on layer 0, group it, then move onto another layer?


Correct. And only the group or component gets the layer association. When you open the group or component for editing and select the edges and/or faces, you should see in Entity Info that they are still on Layer 0. The only entities that should be put on other layers without grouping is dimensions, screen text, and leader text.


Thanks, i have been using sketchup wrongly then, and will follow that workflow


I think you’ll find that it is actually an easier workflow to leave Layer 0 active at all times. You’re less likely to ave problems, too, since you don’t have to continually chase which layer you’re working on.