Why Does Dissolve Edge Delete Faces Sometimes?

I find that when I dissolve edges at the boundaries of an object it tends to delete more than I wanted. See example below.

In this situation, delete edge is even better because at least then the other edges are there and I can rebuild the faces.

Why does this happen? Is it a bug? Because sometimes I do the same procedure on the same geometry and it works as it should and I don’t know why.

You’re trying to leave an L-shaped n-gon that Blender recalculations can’t properly handle.

Why do you need to remove that crucial edge?

Sorry I should have been more specific. I’m working with a triangular shape with subsurf and I keep hearing how triangles are bad, so I’m trying to make it into quads like the below screenshot. But when I delete those edges it removes more geometry than I want.

N-gons are bad if they leave inaccuracies on the finished surfaces when using subsurface modifier. If you’re working with a flat surface, they should be okay.

What you show in that last image should work. That’s how I would do it.

No it deletes the ends like this

Now all you do is add a loop around the very edge to pull the corners sharp.

EDIT: I just tried it and I see what you mean with the corners. The corner vert is being deleted when you disolve the edge.

You can’t delete/dissolve an edge/edge loop without deleting that point at the end if it does not share geometry with another edge.

image

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In the case of no other geometry select the faces and use “f” for merge faces.

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Nice trick! I didn’t know 'f’would do that!

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oops sorry. I meant to reply to you. Answer above. :slight_smile:

Using 2.82 here, the “Adjust Last Operation” panel (in edge selection) has an option for that. Also you can use Ctrl x (Dissolve, Context-Sensitive) and limited dissolve with different applications. The Dissolve Verts option is not listed in the manual.

https://docs.blender.org/manual/en/2.82/modeling/meshes/editing/basics/deleting.html?highlight=limited%20dissolve#dissolve

dissolve-edges

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two great tips!

I’m glad its useful.

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Perfect that’s just what i needed!

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fantabulous