# How to draw curved symmetric lines within a shape

So, what I have drawn in the grease pencil above is generally what I want to create with lines inside the rectangle. I want them symmetric about the Y axis (and the pattern around the x axis inside the shape as well), so obviously a lot nicer than what I've drawn, but that's the basic pattern.

I will also be taking these lines and thickening them inside the shape after I've drawn the pattern and making them into meshes.

Any ideas on the best way to do this? I've been experimenting with curves and linking them and whatnot, seems a little rough when I do it. Any ideas appreciated!

***I tried uploading the .blend to pasteall.org but it said error repeatedly - definitely not too big, so don't know :(

• Joshua Leung(Aligorith) has been reworking the grease pencil tools and has been making many updates. You can follow the commits he's been making at the following site. miikahweb.com/en/blender/git-logs/page/1 Commented Dec 5, 2014 at 6:03

Curves can be a little different from editing meshes but with a little practice can be easy to work with. The array and mirror modifiers also work with curves to help you get the symmetry you are after.

Here I have one small curve with an array and a mirror. You can see the red handles on the real curve piece. To get some thickness to the curve you only need to turn up the bevel depth. You can also use another curve as a bevel object to get a unique shape extruded along the length of the curve.

If you have a bad join between the array pieces like this

you can enable merge in the array modifier and increase the merge distance if needed. You should also adjust the handles on the curve so that the start and end of the curve are pointing straight at each other for a clean merge.

And if you have a non-circular bevel shape you may want to twist the points using CtrlT. With a square bevel you can get the twisted look you get on iron gates.

You can easily convert the curve to a mesh object with AltC

• This was perfect, thanks! I didn't know about the curve depth feature, probably would have been much easier than extruding like I did :). Commented Dec 8, 2014 at 6:43

You could add a Screw Modifier to a plane. Note that the shapes diameter depends on the relative position of the center point which can be manipulated by moving the planes mesh in Edit Mode. The height can be adjusted by the Screw parameter.

• Any way to do this without actually making the surfaces 'screw', and just be flat instead? Like a wave function instead of twisting? Or maybe this would just be easier if I found some 2d drawing program and imported it to blender? Commented Dec 5, 2014 at 17:31