How can I split a large face into nice even triangles?

Question

I have a simple 2D shape outline imported from a .svg file and converted to a mesh.

This shape has been populated with loads of very elongated triangles, which are not very practical for future editing. Instead, I would like to populate it with nice evenly-sized and not excessively elongated triangles.

I have been able to remove the existing subdivisions with a limited dissolve:

I have then tried a couple of options. "Fill" is a slight improvement but still not great:

The best I have managed is using the "Simplify" brush in Sculpt mode. With Dyntopo selected, constant detail, I do a flood fill and get this:

This is getting closer to what I am after, but note that the outline has now been distorted. If I apply the brush manually, I can avoid the edges but then only partially solve the problem. I could use a higher level of detail for the "simplify" but then end up with a lot of excess triangles.

I would like a way to produce something like the bottom image, but keeping the outline as unaltered as possible from the original. Is there a simple way to do this? There is probably a simple answer, I am quite new to Blender.

Answer 1

@susu has a good suggestion in the comments which has worked well for me.

1. Remove the face so that we just have the outline of edges and vertices.
2. Subdivide some of the longer edges so that the vertices are roughly evenly spaced
3. Face -> Grid fill (with all vertices selected)
4. Face -> Triangulate faces

Result:

Answer 2

I ran into this question while trying to do this exact thing and I found a solution which works very well, while preserving the exact geometry of the border of your face.

My method is as follows:

Start with a face. Here's the one I'm testing on, a vaguely crescent moon shaped 1711-gon.

1. In Edit Mode, separate the face from the object it's attached to into its own mesh. (Just select the face in face select mode, and press P > Selection, or right click > Separate > Selection). Then switch to editing that object. After doing this, I have my 1711-gon face all by itself.

   

2. Select the one-and-only face, press E to extrude it, and give it a comfortable amount of thickness. After doing this, I have an irregular 1711-gon prism.

   

3. Go back to Object Mode and duplicate this object (Shift+D, then ESC to cancel moving it so it's on top of the old one). I now have two of my 1711-gon prisms.

4. Apply a remesh modifier to one of them. This will break the face into smaller polys, and the density of those polys can be configured by adjusting the remesh settings.

   

5. Use the object move tool to offset the remeshed copy of the object from the unmodified one, so that the remeshed one is just barely sticking through the top face, like so:

   

6. Now, use a boolean union modifier to combine them together. Go ahead and apply both modifiers, and delete the spare object. Go into Edit Mode, and you should see something like this.

   

7. "Unextrude" the prism (Delete all of the geometry except for the top faces) - you should be left with the original face (whose geometry you want to preserve exactly), with the remeshed copy bulging through the middle of it.

   

8. Now select everything and scale it in the normal direction with a scale factor of zero, this will perfectly flatten it.

   

9. Finally, select the long thin faces around the edges (there should only be a few of them, so just do it by hand), and in face-select mode, run Face > Triangulate Faces. This will turn those straggler weird edges into triangles. This has turned my 1711-gon into a surface with the same border vertices, but comprised of 3419 polys.

   

10. Now that you have broken your face into easier to manipulate polys, you can merge it back into the object it came from, and sculpt/edit further.

As seen in the example, this will work with concave shapes, high vertex shapes, non-edge-loops, any nonsense at all, without any trouble - as long as your starting face is flat. (If it's not you can use the same flattening trick in step 8 at the beginning to flatten it out). It doesn't give you a great deal of control over the grid pattern you will get on the resulting face - I am assuming you don't care, and you only want to be able to sculpt on the face without changing its shape.