Blender 3D: Noob to Pro/Using Inkscape to make advanced Bezier curves
Introduction to Inkscape
editInkscape is a free program that uses SVG (Scalable Vector Graphics) for its file format, and these SVG files can be imported into blender as Bezier curves. Inkscape has some great tools for making advanced shapes that would take forever to make in Blender itself. We will use Inkscape because it is free, and it is very easy to learn.
Installing Inkscape
edit- Mac OS X and Windows: Go to Inkscape.org and click download. there will be installation files for each operating system.
- Linux: Go into the terminal.
For Arch Linux, type pacman -S inkscape
For Debian based distributions, type sudo apt-get install inkscape
For Fedora and rpm based distributions, type yum -y install inkscape
For any other distribution, check your package manager to see if it has a package for inkscape. if not, download the source code at Inkscape.org and run PKGBUILD in the directory of the source.
Inkscape is a pretty large program, so it will take a while to download and install.
Getting Started
editBecause blender doesn't import any effects or filters from SVG files, we will only have to learn basic path modeling. This is very easy to learn, and will take no time at all. Once it's finished installing, open Inkscape. You will see a large empty page and a bunch of buttons to the left. Don't mind the empty page, we won't be needing it. We will re-size this once we are done with the tutorial. Before we get started, I will show you how to use some of the controls. You will probably be right clicking a lot because you're used to blender, but that's okay. Let's start out with a star to practice some of the controls. Click the Star/Polygon tool to the left, and click anywhere on the paper and drag.
Simple Controls
editgo back to "Object Mode" by clicking the cursor icon to the left. Now, let's try out some of the controls:
| Action | Hotkey |
|---|---|
| Zoom In/Out | CTRL+SCROLL |
| Move along Y Axis | SCROLL |
| Move along X Axis | SHIFT+SCROLL |
| Move along both axes | Hold MMB and Drag |
| Select Path/Curve | LMB |
| Select All | CTRL+A |
| Select all paths/curves within a rectangle | Hold LMB and drag (Like selecting icons on your desktop) |
These are only a few of the controls, you will learn more controls later in this tutorial.
Editing your Bezier path
editGo back to the Star/Polygon tool so we can edit the star. You will see 2 dots appear on the star. You can drag these around, and see what happens. Another thing you can do is add more points to the star, change the spike ratio, make it rounded, and make it randomized with the "CHANGE:" Dialog right above your image.
If you want to edit each node separately without symmetry, go back to 'Select and Transform Objects' mode
and click Path>Object to Path. Now you can just go to 'Edit Paths by Nodes' mode
and play around with the shape a bit.
By clicking and dragging, you can move a node or curve an edge. when you make a curve, 2 nodes will show up that you can drag and edit the curve with more precision.
To add a node in the path, select an edge and press the plus button 
to remove a node, press the minus button, and, well, the buttons pretty much explain themselves, so you can just play around and see what you get.
After you think you know how to edit paths pretty well, let's try to make a path from scratch. Click the 'Draw Bezier Curves' button 
and click to add nodes for the shape you want. If you click and drag, you will make a node and curve the node while dragging the mouse. To finish the path, go around to the first node that you made and click on it. This will finish the path and make it a solid shape. When it is done, a outline, or stroke of the shape will appear. If you want it to show as a solid shape, you can click one of the colors on the bottom and it will fill the path with that color.
Now, move the star inside the path (In 'Select and Transform Objects' mode, of course), without it overlapping the borders of the path. If the star is too big, scale it down and hold ctrl to keep the same scale on the X and Y axis. Select both your path and the star, and press Path>Difference to cut a star-shaped hole inside your path.
Congratulations, You have made a completely pointless random shape and learned the basics of creating a shape in inkscape! Now, It's time to get this into Blender! Save your SVG image, and open up blender. Press File>Import>Paths(.svg, .ps, .eps, .ai, gimp) (Blender 2.49). Select your SVG file and the settings are fine how they are. Press OK and see your path appear in blender (You may have to delete the default cube to see it) From here, you can Extrude, bevel, and do whatever you want to you bezier path in blender.
The result may look something like this:
