I was trying to create a tunnel through a tree trunk. I used a tree from the 3D warehouse and created and pushed an arch through it. I was trying to make a cut that goes through but I can’t – when I select both and click on any of the solid tools it says “One of the selected objects is either not a solid or locked.”
How do I make the tree trunk a solid?
that did not work for me
You need to make sure the trunk is a solid and the arch a separate solid.
I downloaded your file. The bottom of your tree is open and making your group, not a solid group. Once I sealed it off and removed your arch, then grouped just the tree trunk, it made it a solid group, then solid grouped arch cut through just fine after that.