I’m using Blender 2.80 and trying to divide an STL into two different pieces using a YouTube tutorial and for some reason it’s not working quite right. According to the tutorial, you create a plane and move it to the point in your mesh where you want the divide. In object mode, you select the plane, then shift-right mouse click the mesh to select it. (I think the tutorial is rather old and you’re really supposed to shift-left mouse click instead). After both the plane and the mesh are selected in this fashion, you switch to edit mode. The two items, the plane and the mesh should still be selected. You then select, “knife project” from the menu and then check the box labeled, “cut through” to complete the task.
The issue I’m running into is I select the plane I created, I select the mesh I want to divide in object mode and then I switch to edit mode. They both stay selected, but as soon as I click on Knife Project under the mesh menu, the plane stays selected but the mesh I want to divide deselects and only minor portions of it stays selected.
Any ideas why it doesn’t stay selected or why the Knife Project command doesn’t work?
Thanks in advance for any guidance.