8
$\begingroup$

I'm, quite new to modelling in Blender and I was experimenting with the extrusion of faces command using the starting cube. These are the steps I followed and lead to my confusion (also see accompanying image showing steps).

  1. Select four faces that are the "walls" of the cube (not the roof or the floor) in the standard view orientation (i.e. Z axis facing "up").

  2. Use ALT E and select "Extrude Faces Along Normals" and drag the mouse out. I see that the faces move outwards and the space between the extrude faces is "filled in" so a larger box is created.

  3. Press the ESC key to abandon the command and press ALT E again and select "Extrude Individual Faces" and drag the mouse out. This time I get a "cross" with space between the four boxes that are created.

  4. Press the ESC key to abandon the command and press ALT E again and select "Extrude Faces Along Normals" and drag the mouse out. This time I get a result identical to that as in step 3 and not the result I expected as in Step 2

It seems that by using the "Extrude Individual Faces" changes the behaviour of the "Extrude Faces Along Normals" when used after this.

I wouldn't be at all surprised if I'm missing something basic in Blender and exposing my "newbieness" but I thought I'd ask to see what that something is?

Thanks.Steps following

$\endgroup$
1
  • 3
    $\begingroup$ Thanks for a really nicely constructed and illustrated question. :) $\endgroup$ Jul 21 '21 at 8:02
12
$\begingroup$

Extruding is unique in blender in that simply pressing ESC does not "cancel" the operation as one might expect (as it does with other things such as scaling). When you press ESC to "cancel" an extrude operation, all it does is snap the extrusion back to as if you extruded by 0 (it duplicates the "extruded" faces, and leaves them in their "starting place"). Thus, you will end up with duplicate faces. To avoid this, you must undo (Ctrl + Z) to fully cancel out of an extrusion. I think you will see the cube behaves more consistently if you do it this way.

$\endgroup$
9
  • $\begingroup$ ok, now i am a bit smarter again ;) thanks for clarifying! $\endgroup$
    – Chris
    Jul 21 '21 at 7:44
  • 2
    $\begingroup$ For the record, it's not a bug - it's so you can do things like (extrude+esc) > scale > extrude again (as opposed to extruding then selecting all the "new" faces, then scaling along normals). $\endgroup$ Jul 21 '21 at 7:47
  • 2
    $\begingroup$ It's one of those gotchas that stumps most of the beginners at one point, and also the reason why there are so many questions where the answer is "Your mesh contains duplicate geometry", but it's also a great time saver once you know how it works. I think it could benefit from being executed differently, because it's the only instance (I think ?) where a single keystroke performs two actions at once (duplicate > Translate), and only one of them is cancelled when pressing ESC $\endgroup$
    – Gorgious
    Jul 21 '21 at 7:52
  • 1
    $\begingroup$ @Gorgious It's not easy to think of a change to this behaviour which would keep the interface minimal, and quick. Perhaps a better signal to the user that they have created new faces would be nice. Color-coding, or something. $\endgroup$ Jul 21 '21 at 9:08
  • 1
    $\begingroup$ @RobinBetts Seems simple enough to me: make ESC cancel the operation, and if you want the current behaviour, you type 0 ENTER $\endgroup$
    – user253751
    Jul 21 '21 at 16:04
9
$\begingroup$

The "Thing You're Missing" is one of the most common causes of confusion in the modelling interface, so don't worry, you're not alone.

If you "abandon the command" with Esc or a right-click, on a generative operation, (i.e. an extrusion or an inset,) you are not abandoning the generation of new faces. You are just abandoning the subsequent movement of new edges. You are dropping the new faces in place.

The next use of AltE > Extrude along normals extrudes the newly generated faces, which are automatically selected, and not a contiguous group. Each single-face island is an 'individual', extruded along its own normal.

To truly abandon all of an extrusion or inset, including the generation of new faces, you must CtrlZ undo the whole operation.

While this is confusing to the unprepared/unwary, it does make for fast modelling in many situations. It is often useful to make an extrusion, drop it in place, and then decide how to transform the new faces. So, personally, I would not like to see it 'corrected'.

$\endgroup$
1
  • $\begingroup$ Thanks for answering my question. It makes perfect sense but it is a bit of the old "trap for new players" situation. I've been using various "CAD" and solid modelling programs way back before Solidworks was a thing. ESC is used in a lot of programs to "abandon" or "cancel" a command. Like most things it's MUCH easier when you understand how it works. $\endgroup$ Jul 21 '21 at 8:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.