BlenderSCAD - bridging the gap between Blender and OpenSCAD

Blender is a powerful piece of Open Source software which is also useful in the 3D printing space. Coming from OpenSCAD or Tinkercad, there are some issues at the first glance:

Revisiting and changing a model seems to be difficult - Joining meshes is less attractive than grouping/ungrouping objects
Undo functionality is not that advanced.
The parametric approach of OpenSCAD is very powerful and yet easy to learn. Blender's Python console is something you may not even be aware of and parameterizing your first objects with OpenSCAD is definitely much easier.
Blender's UI (i.e. the default theme)is way too dark to provide this warm and welcome feeling of Tinkercad or OpenSCAD :-)

This little project started as a proof of concept implementation as I'm just familiarizing myself with Blender and Python. Meanwhile it has matured quite a bit and is a really nice enhancement for Blender.
Here is a screenshot to show the basic idea:

OpenSCAD code

Btw: It's the OpenJSCAD logo

module logodemo() {
  scale([10,10,10]) {  
    translate([0,0,1.5]) {
     union() {
       difference() {
         cube(size=3, center=true);
         sphere(r=2, center=true);
      }
      intersection() {
          sphere(r=1.3, center=true);
          cube(size=2.1, center=true);
      }
	 }
   }
  }
}
logodemo();

Translated to BlenderSCAD

...with added some color and treated as two grouped objects

def logodemo():  
	scale([10,10,10], 
	   translate([0,0,1.5] 
		 , group(   
			 color(purple, difference(
				 cube([3,3,3], center=true)
			   , sphere(r=2, center=true)
			 ))
		   , color(yellow, intersection(
				 sphere(r=1.3, center=true)
			   , cube([2.1,2.1,2.1], center=true)
		   ))	  
		 )
	 )
	)
logodemo()

I've started developing BlenderSCAD on Blender 2.68/2.69. The current version works fine with Blender 2.68 to the recent 2.74 and may still work on older Blender releases (not tested, though). OS wise, I'm using Blender on Windows7 64bit, but also tested it on Ubuntu (well sideloaded on an Android tablet).

Install Instructions

Installing BlenderSCAD is fairly simple: Meanwhile, I've split the project into a python module blenderscad, default user prefs and startup files for the config folder and the BlenderSCAD panel to be placed in the addons folder. Just installing the module is fine, the other two parts can be considered optional. Furthermore, there is a demo script blenderscad_demo.py and some more demo files in the tests and examples folders.

The blenderscad module

First, place the blenderscad directory in Blender's module path:

[installpath]\blender-2.69\2.69\scripts\modules\blenderscad
or
[installpath]\blender-2.74\2.74\scripts\modules\blenderscad

As an alternative, you can also set a path in the console or the demo script to the folder containing the modules.

UI Look and Feel

You can use my startup.blend and userpref.blend files from the config subfolder optionally. These will provide my Blender Theme adjustments and screen area setup as shown in the screenshot above. Place the content of the "config" folder into the Blender's config folder:

%USERPROFILE%\AppData\Roaming\Blender Foundation\Blender\2.69\config
or
%USERPROFILE%\AppData\Roaming\Blender Foundation\Blender\2.74\config

if you are using Windows (Otherwise, refer to the Blender documentation).

BlenderSCAD panel

Well, this exeeds the original scope of providing OpenSCAD like operations and is rather similar to working with TinkerCAD. If you want to give it a try, install the addon and activate it in the user preferences:

[installpath]\blender-2.69\2.69\scripts\addons\blenderscad_toolbar.py
or
[installpath]\blender-2.74\2.74\scripts\addons\blenderscad_toolbar.py

Getting started

SAVE all open work first, better go to a clean document. Open the demo script blenderscad_demo.py in Blender's internal text editor and uncomment the demo section you want to try out. Simply use "run script". This is the easiest way.

You can also save your script as part of a .blend file. Again, caution, there is a line in most of my demo scripts to wipe all objects of the open scene first for rapid testing. Congratulations, Blender is now your OpenSCAD-like IDE. You can even have the code compile while typing (Check "Live Edit" in the editor)

Alternatively, run via Python Console

This option is preferred if you use an external editor for the code.

#Optionally, first clear command history in Python Console:
bpy.ops.console.clear(history=True)
filename = "/BlenderSCAD.py
exec(compile(open(filename).read(), filename, 'exec'))

In general, I recommend to start Blender from a command line (Windows or Linux). This way you see all error messages and warnings.

A few hints

Blender files usually grow with all unlinked objects. It will garbage clean whenever you save and reopen the document. In order to make the "Live Edit" option work reasonable, I explicitly force the deletion (unlink) of intermediate objects and meshes (e.g. before union). Therefore, the files should stay cleaner than while editing a blender file in the usual way.
A last word of "warning": Pay attention to where your source file is saved. ALT+S will save the file in the editor, CTRL+S will save the "materialized" version of that file inside blender. Changes may be lost if you resync.

Supported:

cube
cylinder
sphere
circle
square
polygon
polyhedron
translate
rotate
mirror
scale
resize
color
union
difference
intersection
projection
*linear_extrude
rotate_extrude
hull
surface
import_, import_stl , *import_dxf
export, export_stl, *export_dxf
hexagon
octagon
ellipsoid
rcube
roundedBox
special variables: fs, fa, fn (~ $fs, $fa, $fn)
string functions: echo, str, *search
math functions: lookup, rands, sign, sin , cos,...

Extras

join, split
group, ungroup
clone, destruct
round_edges
dissolve
+several (OpenSCAD) demos
...

Missing

minkowski
norm
multimatrix
...

The BlenderSCAD Panel

This is currently the most active area of my development - subject to change ;-) I wanted to have some interactivity to try some additional operators and tweaks easily. As this is a really simple to do in Blender, I've defined a panel. This is how the first version looked like:

It mainly reuses some code I've written for the BlenderSCAD enhancements. A very handy thing are the multi-object boolean operations: 3 clicks to have a cube, a cylinder and a sphere on the screen, a couple of clicks to align them, selecting several objects (Shift+Right Mouse), then just hit one of the Boolean buttons. Behind the scenes, it will create the required modifiers and apply them. A great productivity gain, I would say. Give it a try. Almost as convenient as Tinkercad (Group and Hole and Undo/Ungroup) still to be done. The object cleanup (using limited dissolve) really cleans up most resulting geometry.
In general, most operations will be applied to the set of selected objects.
Object selection differs from the default Blender setup. I've changed the assignment of the mouse selection in order to make tablet operations (without a keyboard) possible.

Speaking of geometry: The user will not even realize when the code is switching from Object to Edit mode (something not always straight forward in Blender, especially when scripting via Python?). There is a Debug-Button which will toggle displaying all object edges even in object mode. Blender could/can be so easy!

As I need to see the "real" console output anyways, I've decided to switch from the single window-multiple area approach to a triple window approach.

Just tweak the pathes in the text opening in the startup code (right) and run it. This will make the Panel appear - no full-fledged add-on at the time being.

Minimoed / BlenderSCAD