Why can't we get an angle from two connected edges?

I finally had to ask:

Figured I’d check with you guys before assuming it to be a bug.

It’s annoying because I sometimes need to do an unwanted Fill just to take a measurement.


I join to this question. When want to make precise 1/4" thread I want to set angle 30 degrees by fast vertex move, and select Edge Info: “Angle”. But not see angles. Now for measuring the angle I must close triangle and add face, first. Edge lenght checkbox works and edge lenghts are visible. The same is blender 2.66, 2.70, 2.71

I didn’t write the code. But I would guess that it’s because if you displayed the angle between edges that are not part of the same face, any pole where say, 4 edges come together would have to display 12 angles instead of four (including reflex angles). One is a simple case, and one would be very hard to read and make sense of.

Edge lengths are not ambiguous and therefore there’s no problem in showing those without faces.

@piotrpl: you say ‘precise’, but ‘fast vertex move’ even when the angle is displayed won’t ever give you precisely 30d. A precise way would be to start with a horizontal edge and then rotate one vertex with the pivot point set to the other vertex, with snapping on and set to increment.

My projects are not for NASA :slight_smile: so I mean “precise as possible” in fast modeling. Documentation says: “Display selected edge angle, using global values when set in the transform panel”. As you say, when select e.g. 10 or more edges may by hard to read Edge Angle, like top of cone when Face Angle is selected, but this functionn works, and Edge Angle want not.


Definitely not a bug. There just isin’t a mesh display option to see the angle without a face

This is angle of only two faces connected with one edge. But why want not work without fill, if verticles are merged?


Because the edge doesn’t have an angle without the faces. It’s just an edge. A line connecting two points in 3D space.

You are correct. I would expect it to ignore the ambiguous cases because it would get unusably cluttered. But usually if I want multiple angles simultaneously they are the angles of faces anyway, so I could see them by checking Face Info: Angle.

More often I want to find out just one angle at a time, so it would make sense if clicking two connected edges would reveal the Edge Info.
Also remember that an n-gon is a type of edge loop - and edge loops could be programmed to display only the angles of their connected edges.
In the example below, Blender requires that we fill this edge loop (irregular hexagon) to view its angles, but ironically the fill makes it harder to read the angle values.

Still, cases where we want to see an edge loop’s angles are not as common as cases where we want to see a single angle.
If we could get an angle just by doing this it would be a great help:

OK, I undersdand, face is not only filling and when no face no angles. When I move verticles on X axis in opposite directions angle is still 90, when no face, no info about it?


I have only last question, should not be visible angles when more than two faces are connected by the same edge?


When you Sheer those verts along X, or rotate while constraining to Y, the edge the form still has a center point where your red dotted line is. So the plane’s angle hasn’t changed.

Because then what would you do in a case like this:

Display angles A-B, B-C, C-D, D-A?
What about A-C, B-D, C-A?
You need to draw the limit somewhere or it gets out of control, as DruBan said.

[Note: Ignore the outdated image below. It’s because of a bug in the forums that an attached image from a cancelled post appears in the next reply you post - and cannot be removed even with the “go advanced” editor.]


No one has mentioned this so I’ll throw it in - you can measure any angle with the ruler/protractor, with snapping enabled you can snap to the . It won’t help to make something a particular angle though.

I’m glad you mentioned the Ruler/Protractor. This is a useful tool in theory, and I appreciate that it gives a high degree of precision (six places after the decimal when measuring length), however… the snapping doesn’t work reliably. Seems it can snap to edges but not verts (?) even though I specifically enabled Vertex Snapping. Is it just me?I’ve seen some people getting it to work in YouTube videos, but that is not the behavior it exhibits on my system.

It could be made useful for this purpose if it had the ability to auto-update. Like once snapped to a vertex or edge it would stay snapped to it, even as you move or scale that geometry.
But once you exit the tool it’s gone. This tool is a nice idea, but the implementation needs work.

You are right, it needs a ‘pinning’ option.

About the not getting it to snap to verts properly, there are two things to remember (I’ve found this in my own practice, bear in mind I am not, to the best of my knowledge, the person (Howard??) who wrote this tool).

  1. No geometry is hidden from the ruler, so it will snap to verts that are hidden, or behind something, or gone to the loo but someone is holding their seat for them, etc. This can look pretty erratic.
  2. This works much better in ortho mode than in perspective mode, no idea why, and especially for verts. Try it and let me know if you observe this too! I might b seeing something completely different.
  3. Because of 1. above this tool is pretty useless on a dense mesh. Best use is to set up guide type geometry or in the initial stages of modeling.

I learned how to measure after draw, but I am thinking about measuring e.g. two edges without face (like Quantum Anomaly ask in first post) on the fly during joint vertex moving.

it is not easy to snap angle to verticles, I would also “Ruler/Protractor” as option it can be glued to edges and verticles, and move/rotate with them.

Thanks, I do as you wrote. Would you look on UTS threads easiest way First draw horizontal line, next rotate.

Hi Piotr nice job on tutorial! 0430-0440 are you creating nonmanifold geometry? looks like it.
Nice to do it yourself but of course there is the Bolt Factory add on to doexactly this .

Yes, I know the Bolt Factory :slight_smile: I like to learn from the basics, it helps me to understand 3D modeling and features of Blender. I like create tutorials, it is training for me, and may helps other beginners. About nonmanifold geometry - thanks, You are right. I did not check after Remove Doubles that removes only 1 vertex. There is appendix