# How would I make a perpendicular cut into a mesh with a rounded, angled face?

I want to cut the base shape with the cylinder in front of it after aligning its center edges with the highlighted edges on the base shape (as seen in the second frame of the first image). I additionally hope to have the cylinder bend on the faces of the base shape, to make all cuts perpendicular.

• The cutting cylinder should be parallel to the base shape.
• The cutting cylinder's center edges should be aligned (and overlapping) with highlighted edges in the second panel of the first image.
• The resulting cut should be perpendicular to the base shape's walls.

I have successfully used the boolean operator to make cuts in shapes, but I cannot for the life of me figure out how to line it up, much less have it bend to conform to the faces of the base shape.

I am also considering adding a lip around the new opening, but I am hoping that a loop cut or something can solve that - though if I'm mistaken then assistance on that would be appreciated as well.

Any advice is appreciated, and I thank you for taking the time to read my post.

Edit: I have added a new image showing a very rough mock-up of how I want it to bend, though I hope it to do so along the face lines.

• I don't understand why you need the disk to bend. Is the base shape hollow or does it have some inner thickness? Commented Apr 23, 2023 at 7:34
• So this question is not about cutting really, it's about aligning? Commented Apr 23, 2023 at 8:35
• @lemon The base shape is hollow, yes. The disk bending would allow for the cuts into the depth of the shape to be perpendicular to the face and avoid projection/parallax shenanigans with the cut direction. At least if my understanding is accurate, I could be horribly off-base. Commented Apr 23, 2023 at 9:21
• Is this the result you want? (It would be more conventional to create the hole from the surface) Commented Apr 23, 2023 at 11:21
• @RobinBetts the intention behind this model is to import it for use in a game - which would benefit from more than the ten edges making up the circle cut-and-lip in the image provided for the sake of appearing smoother, as the game's smoothing won't bend it as nicely as Blender apparently does. Commented Apr 24, 2023 at 11:26

A proposal that is not directly an answer to the question, but that could interest you.

Considering the disk size fits inside the four faces of the base mesh. We are in this situation:

Select the center vertex and duplicate it (we'll need it later).

Select again the center vertex and CtrlShiftB to bevel the vertex. Expand the bevel until it reaches the sides.

And in the operator panel, set 8 segments (in order to have a circle with 32 vertices), and as "shape" parameter set 0.086 'magic number' to have a circle.

Now remove the inner vertices to keep the circle only. Extrude scale 0 the circle ES0 and merge it to the vertex center (the one we have duplicated at the begining).

Finally extrude along normals to the wanted size AltE then "along face normals":

• While a very interesting technique that I will likely find use for in the future (and I thank you for providing it), I don't think this will work in this instance because of the non-uniformity of the faces and the disk's diameter being longer than the four faces' width (hence the desire for the bend). Commented Apr 23, 2023 at 10:44
• I actually ended up using this method after merging some vertices to allow it to be a sufficiently large circle, then extruded it, copied it onto the base mesh (with regular vertices), difference boolean operator, and then extruded the resulting cut. It probably isn't PERFECTLY perpendicular due to the merging of vertices but eh good enough. Thank you for the help! Commented Apr 26, 2023 at 5:09