How to bevel a vertex corner that is between a circle and straight?

Only way I can imagine doing it is by manually adding a circle and editing it into the shape. Which is slow. Same with knife project and that also creates other issues and is also slow. Maybe there is some magical hotkey with the bevel that can do it or something?

This pretty much exactly what the Spin tool is for ..

In an orthogonal view of the circular arc you want to create, put the 3D cursor at the center of the new part-circle, select the vertex you want to extrude around it, and invoke the tool.

In your case, you might ShiftS snap the cursor to the two selected endpoints of the bevel, so it's exactly between them.

You can adjust the center during the operation by using the arrowheads, and the number of vertices generated in the sweep using the tool's Adjust Last Operation panel

• If you try it on the example in the image you'll find out the spin tool is way too cumbersome to get the circles to line up. It works but it is really slow and pretty anoying way to do it imho. Commented Apr 1, 2020 at 12:12
• @user79164 OK, I hear you. There's no circle guaranteed to be tangential to the curves at both ends. (Its center would be at the intersection of the perpendiculars to the curves in their plane, which is not necessarily equidistant from their ends). Are you asking for the arc to be tangential at one end, say, the one on the straight line? Commented Apr 1, 2020 at 14:00

You can sort of do it with CTRL+B, then V. But that gives you this:

Which isn't exactly right and you have to delete some of the vertices that get in the way.

• It is quicker to just copy paste one circle around and manually trim the extra verts. I wonder if there is a trick to get at least round shape with your bevel trick? Commented Apr 1, 2020 at 11:32

Using Bevel and TinyCAD (addon comes with Blender) you can do it the following way:

If the connection is not needed to be precise, you can eyeball the intersection instead of using the Addon!

First the visual step by step (Details written below):

1. Remove unneeded vertices.
2. Select the vertex left at the top of the curve.
3. Press G twice for slide along edge. Move the vertex down a bit first.
Then press C to disable Clamping and move the vertex up above the top edge.
4. Select the two intersecting edges and use "TinyCAD"->V2X function to create a new vertex at the intersection.

5. Select the 2 vertices at the end of the 2 intersecting edges first and then the new vertex last by holding Ctrl, leaving the last one active (white).
6. Press Alt+M -> At Last (the new vertex is not connected, so doing this will connect it while at the same time removing the other 2 not longer needed vertices).
7. With the new vertex selected press Ctrl+B followed by V to activate Vertex bevel mode.
8. Moving the mouse to increase the radius and scrolling the mouse-wheel to adjust the number of vertices in the bevel you can find the fitting curve.
9. You may have to pull the bevels vertices close to the existing vertices, so it's recommended to press Alt+M -> By Distance to clear any vertices that may have come to lie on top of each other.

The result can look like this:

• This is pretty simple and you don't even need the tinycad addon if you move verts manually approximately to the right places. Doing several corner roundings with this way is very slow tho. Commented Apr 1, 2020 at 12:14
• Sure is slower then a function especially for it, but believe me it looks more cumbersome when explained then when used. Also added that TinyCAD is only needed when precision is needed. Commented Apr 1, 2020 at 12:15