Extrude and bevel an imported svg curve

Question

I exported an svg 1.1 file from Adobe Illustrator CS6. I joined all the shapes by pressing Ctrl+J. I set the curve shape to 2D. Then I extruded using the right hand side panel:

So far so good. But when I try to apply even a slight bevel, all hell breaks loose:

It does get less insane if I bring the bevel down by multiple factors of 10... But then I really don't have much of a bevel.

Am I doing something wrong? Am I using the wrong kind of object? Should I be doing this with meshes? Do my curves just need cleaning up?

Answer 1

Most likely your curves need cleanup.

Diagnosis

You mentioned joining all objects after import, make sure all segments are closed curves, not separate lose segments inside one bezier object.

I would advise checking for any loose vertices, and more importantly overlapping segments, which are the most likely to cause the artifacts similar to your screenshot. Besides that very tightly close vertices, very short segments, and mostly very sharp angles tend to cause problems with beveling.

Illustrator often adds filters and effects (like drop shadows, outlines, or contours) that when converted to SVG become loose curves overlapping the original shape that often cause issues. Make sure to disable or exclude them before exporting, or cleanup afterwards

In your case the most likely culprit is the the font objects. Check the text part of your logo, fonts are often sloppily designed or of low quality, or simply not prepared for 3D modeling and contain overlapping or very close together vertex which can cause problems.

Cleanup

To clean up the curves the best method I could think of consists of selecting one vertex belonging to a text character; make sure you select the right one as there are often several overlapping. Blender highlights the whole spline that vertex belongs to with a different color so make sure you are not selecting a duplicate by checking if the whole character is marked with a different color (as opposed to marking only the single vertex you select).

Then proceed to select all linked vertex by pressing Ctrl+L making it easy to hide them with H

You are then left only with the loose or duplicated vertex visible which can easily be discarded by deleting

Anyway here is the clean file, problems were as suspected the font objects

Answer 2

This is the result of really messed up topology. This is to be expected when you're working with curves. Remember, curves are geometry also! The main difference between them and vertex based objects are how you interact with them.

There are two ways that you can get a clean enough mesh for beveling. You can clean up the original mesh, or you can remodel it. I personally would remodel it. This is usually a cleaner and more controlled way to do it because you're deciding where the geometry goes instead of letting Blender do it.

Cleaning up the original mesh

Start off by removing the bevel and extrude. We'll bring those back once the text is a nice clean mesh.

Then press AltC and select To Mesh. This will convert your text from a curve to a mesh.

Then Tab into edit mode. Now we'll start the actual cleaning. To start off, press W and select Remove Doubles. This will remove the doubled vertices which are extremely common in meshes like this.

Now comes the hard part, removing geometry. The most important thing is the outline, so start by removing all the interior faces. Press A then X and select only faces. This will get rid of all of the faces. But the edges will still be there, so carefully select some of the unnecessary edges (I like to box select them with B, and delete them (always use the edges option, using selecting vertices will delete remove the outline). Make sure to leave the outline intact.

Now that we've gotten rid of the interior edges, it's time to clean up the outline. Why?

(img)

Well, I think think I need to say anything...

There are a lot of edges that are somewhat like that. To take care of them, let's switch to vertex view mode using CtrlTab so that we can see them.

Start by selecting some of the virticies that are in streight parts of the lettering. Press G to move them. You're looking to see if they're dragging along any other edges. If they are, delete them. This time, use the Vertices option.

This get's rid of most of the harmful edges and virticies. Now it's time to get rid of the ones that just aren't necisary for the shape. These are vertices that are in straight parts of the mesh, and vertices that don't give any more important information to curves.

With these ones, select them individually, and delete using the option of Dissolve Vertices.

Just be sure that you don't remove too much it can be hard to go back. For me, I tend to remove every other vertex while making sure that what I'm removing doesn't effect everything else much.

Finally, carefully work on filling in everything. For this, just try to follow good guidelines of topology. Avoid triangles, but be okay with adding them if necessary. This part of it is hard to really explain because you basically just have to give it a try and see what works.

Modeling from scratch

This is probably my favorite method for doing things like this. You can see part of the reason above, the first method is a lot of work. I find for these kinds of things, I prefer starting from scratch because I can completely skip the cleaning part, and go straight to making an outline, and then filling it in.

To start off with this, bring in a background image of the logo/text, or import the logo/text and place it below the grid. Go into top view, add a plane, go into edit mode, and delete three of the verticies. From here, move one of the remaining vertex into place, and use CtrlLeft Mouse to extrude out an outline.

Then fill it in like we did in the first method.

Extruding and Beveling

To finish off those two methods, we need to extrude out the logo, and we need to bevel it. Do this by adding a solidify modifier and a bevel modifier and adjusting the settings from there.

Answer 3

Because .svg imports into Blender as a curve object, you need to convert it to a mesh with Alt+C>mesh from curve/meta/surf/text. Then you can modify the object however you wish.

Answer 4

I found that straight-line corners were problematic, but curves where bezier handles create curvy curves were not.

A relatively quick fix is to select vertices and then, while in Edit Mode go to Control Points > Set Handles Type > Vector.

Seems to clean thing up quickly.