Home → NodeBox OpenGL →

How can I use the old nodebox libraries (like L-System) in Nodebox for OpenGL?

• Edit

kenzenichinyokiai

01 Nov, 2013 07:39 PM

I tried ximport, but it doesn't work in NB OpenGL, right? I also tried to copy the LSystem class into my code and then build an L-System object using the example code provided but it didn't work. ('tree = lsystem.create()' and 'tree =LSystem.create()')

Sorry if the question is too 'newbish', I'm not an experienced programmer and hadn't tried doing anything in Python before.

Thanks!

1. 1 Posted by kenzenichinyoki... on 05 Nov, 2013 06:45 PM

   

   Hi!

   Here's my last code:

   # Import the library
   from nodebox.graphics import *
   #from lsystem import *
   try:
       # This is the statement you normally use.
       lsystem = ximport("lsystem")
   except:
       # But since these examples are "inside" the library
       # we may need to try something different when
       # the library is not located in /Application Support
       lsystem = ximport("__init__")
   reload(lsystem)

   # Create a simple treelike pattern.
   tree = lsystem.create()
   tree.rules = {
       "1" : "[-FF-FF1][+FF+FF1]"
   }

   # Each F command depletes a little bit of time.
   # Calculate the total time we need to grow 6 generations.
   done = tree.duration(5)

   # Our custom segment is a pinkish oval.
   # When we divide the current time at the segment by done,
   # we get a number between 0.0 and 1.0 we can use for coloring.
   def segment(length, generations, time, id):
       t = min(1.0, time/done)
       fill(1-t*0.75, 0, 0.5, 0.6)
       oval(-length/2, -length, length, length)

   tree.segment = segment

   # Animate the growth of the tree using the FRAME count.
   size(500, 250)
   speed(20)
   def draw(canvas):
       
       time = min(FRAME*0.1, done)
       tree.draw(250, 250, 5, time, ease=8)
       
   canvas.run(draw)

   And here are the errors listed in the console:

   Traceback (most recent call last):
     File "E:\workspace\Test2\src\test2.py", line 42, in <module>
       canvas.run(draw)
     File "E:\workspace\Test2\src\nodebox\graphics\context.py", line 3918, in run
       pyglet.app.run()
     File "E:\Python2732\lib\site-packages\pyglet\app\__init__.py", line 264, in run
       EventLoop().run()
     File "E:\Python2732\lib\site-packages\pyglet\app\win32.py", line 63, in run
       self._timer_func(0, 0, timer, 0)
     File "E:\Python2732\lib\site-packages\pyglet\app\win32.py", line 84, in _timer_func
       sleep_time = self.idle()
     File "E:\Python2732\lib\site-packages\pyglet\app\__init__.py", line 187, in idle
       dt = clock.tick(True)
     File "E:\Python2732\lib\site-packages\pyglet\clock.py", line 700, in tick
       return _default.tick(poll)
     File "E:\Python2732\lib\site-packages\pyglet\clock.py", line 303, in tick
       item.func(ts - item.last_ts, *item.args, **item.kwargs)
     File "E:\workspace\Test2\src\nodebox\graphics\context.py", line 3847, in _draw
       self.draw()
     File "E:\workspace\Test2\src\test2.py", line 40, in draw
       tree.draw(250, 250, 5, time, ease=8)
     File "E:\workspace\Test2\src\lsystem\__init__.py", line 182, in draw
       self._grow(generation, self.root, angle, self.d, time, draw=True)
     File "E:\workspace\Test2\src\lsystem\__init__.py", line 131, in _grow
       draw
     File "E:\workspace\Test2\src\lsystem\__init__.py", line 145, in _grow
       self.segment(length, generation, None, id=self._segments)
     File "E:\workspace\Test2\src\test2.py", line 28, in segment
       t = min(1.0, time/done)
   TypeError: unsupported operand type(s) for /: 'NoneType' and 'float'

   What am I doing wrong? It is important for me to create LSystems, and why not, use the other clibraries you built for Nodebox 1 in Nodebox OpenGL.

   By the, way, and also very important for me: can you export to PDF using Nodebox for OpenGL? I don't have a Mac so for me this is the option to use 'just code'.

   I love your tools.

   • Edit

2. Support Staff 2 Posted by tomdesmedt on 04 Dec, 2013 12:17 AM

   

   Old libraries from NodeBox 1 that "draw stuff" can't be used in NOGL, since the drawing operations are very specific to NB1. Nevertheless, NOGL ported a lot of code from the libraries (e.g., boids, colors, ...) but unfortunately not L-systems.

   You could look at the source code of the L-systems library, and replace the drawing commands (they start with "_ctx") with NOGL commands. Here is a simple L-system in Javascript which should not be hard to convert to Python code:
   http://www.clips.ua.ac.be/media/canvas/?example=lsystem

   NOGL does not have support for PDF, since it draws pixels for speed and not vectors. So chances are pretty slim it will ever support PDF. There is always a trade-off: either it is fast (=graphics card accelerated, pixels) or either it is slower but scalable (vector curves, PDF).

   Best,
   Tom

   • Edit