I need a simple way to cut away different parts of a mesh, like shown in the pictures below. I tried to use the extrude tool but it does not make a clean cutout of the mesh.
This is what I want:
I get this when using the extrude tool:
Just model it. From your cube, add two edge loops around the middle and top (ctrl R in edit mode):
Delete the four faces where you don’t want them (select the faces and hit “X”)
Select the opposing edges on the top hole
Press “F” to add a face, and repeat with the lower hole
You can also use a boolean modifier: https://www.blender.org/manual/modeling/modifiers/generate/booleans.html?highlight=boolean just don’t expect too good topology afterwards.
There is also the boolean modifier. It is however more time consuming for simple operations due to having to fix the topology, Roken’s method is recommended.
Though i would add that selecting the top edge and double tapping F is a bit faster.
Attachments
Boolean.blend (449 KB)
You live and learn, I didn’t know about the double tap. That saved me 7 or 8 seconds 
Can do it in many ways
from left and upwards:
- automerge editing and vertex snapping
- delete and grid fill
- delete and F2 addon
Could also:
- delete and bridge edge loops
- fill the hole and mesh -> clean up -> split non-planar
hmm… This was not as simple as I hoped it could be. I’m coming from Sketchup and it’s sometimes hard converting to Blender. Strange there’s no way to just drag and cut out the part I don’t want. A similar tool in Sketchup makes this super easy.
Anyway, I’ll be using Boolean modifier with difference for my purpose. Not the most efficient solution but it does the job.
Thanks, I did learn some new things from your answers
Sketchup is closer to CAD compared to Blender which is a polygon modeling program.
Also, ask anyone what a nightmare it is to export a mesh from Sketchup into another program for further editing.
Hi
Here is a great addon ( Carver )…Fast and easy to use…But it don’t work on Subdiv.
Hmmm…Not sure if it is in Blender…Could be…Check Preferenses…Type Carver to find it.
Tai
The boolean modifier is a way to go but will leave you with problems down the line. CAD software uses boolean operations all the time for things like this, and usually references all construction processes as you create. The underlying meshes can have much different resolutions, even for areas that are right next to one another. In polygonal modellers, edge flow is very important and making things tidy is paramount to a good result. Too many boolean modifiers, and you leave yourself not able to edit the underlying mesh.