Fill a solid corner topologically correct

Question

When constructing technical objects I often come to a point where I want to add something into a corner. I haven't found an easy way to do so in a topologically correct way.

As a simple example this would be the situation with the corner to be filled

And this is the target to be achieved:

Given how easy it is to extrude such a block, I wonder if there is no easy way here as well.

Solutions I've tried so far:

extrude one of the two adjacent faces -> this gives a topologically incorrect model which causes problems later on
add a cube of the desired size, and make a boolean union -> (almost) impossible to avoid creating small steps and quite cumbersome
extrude one edge and fill the three faces manually afterwards. -> this is topologically correct, but still a bit cumbersome
isn't there an easier way???

You might pick up a thing or two from https://blender.stackexchange.com/questions/76521/how-can-i-make-an-indented-cube-without-using-a-boolean-operation — iKlsR, Jun 19 '17 at 10:09
Very much related: Make quad face from where two edges will meet? — David, Jun 19 '17 at 12:47

score 8 · Accepted Answer · answered Jun 19 '17 at 10:52

8

If you have F2 addon enabled, here is a very magical trick.

Pressing F when F2 is enabled, several things will happen:

If 1 vertex is selected, it will create a face from the 2 edges connected with the vertex in the direction/position of the mouse cursor.
If 2 vertices or an edge is selected, it will try to created a quad face with the adjacent edges/vertices. And the result doesn't need merging or 'remove double'.
If 3 or more edges are selected, it will simply create a face with selected edges. Result can be an N-gon.

answered Jun 19 '17 at 10:52

TeaCrab

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That's indeed a very magical and helpful trick! Thanks :) – derHugo Jun 20 '17 at 05:08
@derHugo, thanks to the developers of the F2 addon. It's such a nice feature. – TeaCrab Jun 20 '17 at 20:25

score 3 · Answer 2 · answered Jun 19 '17 at 10:01

3

I've tried some methods with Bridge Edge Loops, Grid Fill and such, but I think that the fastest way would be this one:

Remove corner Edge.
Select Edges around one corner wall.
Turn on Snapping to Vertex.
Extrude along needed axis - E > X in this example.
Create Face - F.
Select all (A) and W > Remove Doubles.

answered Jun 19 '17 at 10:01

cgslav

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nice trick to plan ahead using "Remove Doubles". But the F2 addon from @TeaCrab seems not only faster, but also more versatile (works as well for example if extrude is not along an axis). – kameamea Jun 19 '17 at 13:57
The method @LukeD provided can be useful when the geometry isn't simply 3 missing faces. His method is much more efficient when there are a number of edges along a hole, F2 in that case will be a bit of headache. – TeaCrab Jun 19 '17 at 18:13

Fill a solid corner topologically correct

2 Answers2