Sunday, May 12, 2019

Python Scripts in Art of Illusion

I took a break from the cloth simulator to look at adding Python as a scripting language for Art of Illusion. I had some success at pulling in the Jython library and was able to get the following Tool Script to add a Cube to the scene:

undo = UndoRecord(window, True)
obj = Cube(1.0, 1.0, 1.0)
objInfo = ObjectInfo(obj, CoordinateSystem(), "Cube "+str(1))
window.addObject(objInfo, undo)

In a video I demonstrated that a Groovy script could be used to add a Cube to the scene. The Groovy script was as follows:

undo = new UndoRecord(window, true);
obj = new Cube(1.0, 1.0, 1.0);
objInfo = new ObjectInfo(obj, new CoordinateSystem(), "Cube "+1);

window.addObject(objInfo, undo);                      

As you can tell, the code is essentially the same except Python doesn't use the new keyword, True is capitalized in Python, and Python won't concatenate an integer to a string without a conversion function. I'm sure there will be more noticeable differences once I start using it along with the language features of Python, but this was just a proof of concept.

Unfortunately, I've been less successful at implementing the code required to use Python to create a Scripted Object in Art of Illusion. It might be easier if I were modifying the Art of Illusion code rather than trying to do this as a plugin, but I keep running into one typecasting issue or another. I had hoped that I might use this as the vehicle to demonstrate the value of the reference material at the back of Extending Art of Illusion. I can say that I've had the book open to that material the whole time I've been working on this and I have put it to good use. I can also say that I'm very glad this book is available in hardback. It costs a little extra, but being able to open it and leave it open makes a world of difference.

UPDATE: After writing this I found a way to get it working for Scripted Objects. I put it in a repository at so I wouldn't lose what I had working. It's not ready for general use, but it is working. To use it, you will need to have the Jython.jar file in your class path for Art of Illusion. If you know what that means then have fun. If not then it's probably better that you don't mess with it. I would explain it but I only just got it working myself and I don't know that I can give you a clean cut set of instructions yet.

For anyone who is interested, the following is the Python version of the Axis script that is in Extending Art of Illusion:

from artofillusion.script import ScriptedObject
scene = theScript.getScene()
count = 0

length = 5.0
size = 0.01

def createAxis(length, diameter):
  axis = Cylinder(length, diameter, diameter, 1.0)
  return ObjectInfo(axis, CoordinateSystem(), "")
obj = createAxis(length, size)
if not obj is None:
obj = createAxis(length, size)
obj.getCoords().setOrientation(90.0, 0.0, 0.0)
if not obj is None:

obj = createAxis(length, size)
obj.getCoords().setOrientation(0.0, 0.0, 90.0)
if not obj is None:

You may notice that I'm using "theScript" here instead of "script". This is because there is a conflict between "script" and "artofillusion.script" with Jython interprets the code.

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