# Boolean intersect two 2d extruded bezier curves (non destructive)

I understand that the boolean modifier is not available for bezier curves that are 2d and have been extruded.

However, is there a way to apply a simple "conventional mesh" modifier to this curve and then stack on top of that a boolean modifier?

Basically, I want to boolean intersect two 3d object in Blender, these objects are both 2d bezier curves that have been extruded to give them a 3d shape.

EDIT: I really need to use non destructive actions on these objects.

EDIT 2: I am very surprised there are no modifiers in Blender that simulate alt-c, Mesh from Curve for these types of purposes.

• You can convert them to a mesh with Alt C, but this is a destructive action (you can't convert them back to a curve)
– gandalf3
Oct 18 '14 at 7:53
• Thanks, @gandalf3, I would prefer to not have to use any destuctive actions, I will most likely need to edit the curves after the boolean is applied. Oct 18 '14 at 7:55
• You are not the first, I too have often wanted an Alt C modifier ;) Sounds like the kind of thing modifier nodes would do.. Anyway, you can join the curves and they will sort of auto boolean, but the filling algorithm sometimes has trouble with complex intersections..
– gandalf3
Oct 18 '14 at 7:59
• The only trouble with joining the curves, is that the 3d extrude will the the same depth throughout. I need one of the curves to subtract only half the depth of the other. :( I'm thinking ALT-C, Mesh from Curve might be my only option. Oct 18 '14 at 8:03
• Hm.. sounds that way :/ I often keep a copy of objects on another layer before applying some destructive action like this, so it's easy to go back if needed.
– gandalf3
Oct 18 '14 at 8:05

Well I found some time to try and code an add-on that will do what I think you are talking about. It is found here, or on this thread. To use:

1. Install

3. Add a mesh object like a cube

4. Go to the modifiers tab and select the curve's name under the Curve Conversion part

5. Click Update Mesh

What it does is automatically converts the curve to a mesh and replaces the current objects data. It will respect any materials or modifiers added before you press Update Mesh. The Respect Scale option copies the scale from the curve. So if you scale the curve up the mesh object does the same.

Let me know if this is what you were talking about.

## EDIT: Check Blender Artist thread to get updated instructions as they come

• Thanks! I'll give it a go when I get home, may I ask, will this work for two curve objects, not just one curve and one mesh? Oct 29 '14 at 4:50
• It'd be great if you posted the script on BlenderArtists so that there's a place others can find it :) Oct 29 '14 at 10:29
• @Joseph You just need one mesh object for every curve. You can have as many overall as you would like. You can also have multiple mesh objects for a curve. Oct 29 '14 at 12:25
• @Joseph did this work for you? Oct 31 '14 at 16:29
• @BlendingJake, Thanks, I really think they should add this into Blender core. :) Nov 1 '14 at 23:11

I do not know exactly what you are trying to accomplish, but I would recommend trying a curve modifier. Don't actually use a curve to apply the modifiers to, but apply the modifiers to a mesh, and then add a curve modifier to make the mesh follow the profile of whatever curve you select. Like so:

This is how it looks in the viewport, on the right is without the curve modifier, and on the left is the mesh with the curve modifier.

If I understand you correctly, this should be just what you are looking for. Feel free to drop a comment below if that is not the case or something is not clear.

Yup, that would be possible however you need to convert the curves to meshes first of all. This you can do by selecting the curve and pressing Alt+C and selecting Mesh from Curve. Then you can perform any mesh manipulation tool/modifier that you like.