Creating NC files from Blender 3d Bezier Curves

Chinese Char 'I LOVE YOU' Example

Font Characters Into Blender

Normally getting text into Blender is simple - hit the space bar and add text.
Then select the font you want and you're home free.

The WarpToolText-XviD video at Eugene's Blender Video Tutorials shows adding text in Blender very well.

When working with chinese characters I've been unable to use 'add text' in Blender
so I have to import the characters in another way.

To cut chinese characters on a ring it is important to start out with high resolution graphics.
The NJSTAR Chinese Word Processor has chinese true type fonts so when I can find the correct
characters I can get high resolution graphics on my computer monitor.

A search for 'I love you' at http://www.online-chinese-dictionary.com/ produces:

Getting the characters into NJSTAR is now a simple cut and paste:

i love you chinese characters

A screen capture yields a usable high resolution graphics file (lov_you.jpg).
Yea, I wish I could find a better way - but this works.

What I really want is a *.svg graphics file I can load into blender.

I use InkScape to convert the jpg file into a svg file.

Open lov_you.jpg in InkScape. Select the jpg file and then select 'path', 'trace bitmap' command.
Accept the defaults and then save the file as lov_you.svg.

inkscape lov_you.jpg

Open Blender, Import lov_you.svg

I'm going to assume you have a working knowledge of blender
so I'm not going to try and explain everything.
(Take a look at the video tutorials on the www)

Click on Import

import lov_you.svg

Click on Paths

paths import

Click on InkScape

and (with any luck at all) you should end up with something like this

To do: wrap the ring design around a model and rendered it.

Create NC files

Select the Bezier Curve Object
Click on Export

Click on Export Bezier Curve Pts (xyz)....
(if this option is not avaliable you need to copy export_curves_xyz.py to the scripts folder)

Rename the file extension from .blend to .xyz
and then Click on Export Bezier Curve Points

Exit Blender and run BezierNC.exe

BezierNC.exe will create 3x Cartesian Frame and 4x Cylindrical Frame NC files.

lov_you_doc.ZIP BezierNC ASCII text (can be input into cad-cam programs)

lov_you_3x.ZIP Cartesian Format NC File

lov_you_4x.ZIP Cylinderical Format NC File

Conclusions

This process is not limited to fonts or text.

It will work with any jpg file or *.svg graphics file with bezier curves.
You can create a set of bezier curves from files you can import into InkScape
or you can create bezier curves directly in Blender. InkScape has a larger set of bezier editing tools
(The boolean operators are expecially interesting)

Will generating NC files this way replace general purpose cad-cam programs?

Not yet... but this process works well for contour milling and is a useful tool to generate
files that can be imported into cad-cam programs (the ascii text xyz pt file).

Can you go back and forth between Blender and InkScape to edit bezier curves?

Well, creating *.svg files in blender (to input into InkScape) isn't very easy.
So far - the only script that I've found that can do this is the BezierExport.1.py script.
This script's output is 2d bezier curves (relative to the camera). To be useful (for back and forth editing)
you need to remove the camera rotation and translation modifiers. (select the camera, alt+r and alt+g)

Why would you ever want to go back and forth between Blender and InkScape?

Well, If you want to create pocketed tool paths with BezierNC you will need to offset bezier curves.
This is easy to do in InkScape. In InkScape you can also do boolean operations on bezier curves
(ie. pocket a design to another path - ie. rectangle)

There are so many different ways to do the things in Blender - I'm just trying to find a
way to generate tool paths and this is the best I've come up with so far.

That's it....
If you have any questions, corrections, easier ways to do things and/or comments..... please email me.

Roy Goodell
5xj@5xj.com