Elements

About

The Elements project is all about free and easy 2D physics for python -- with main attention on:

1. An easy-to-use, fast 2D physics API
2. Examples and documentation on how to use the API
3. Providing the examples as bundles, as they are already interesting and fun
4. Speed optimization (also with an eye on the XO laptop :)
5. Development of ideas for education and playful-learning

File:Elements.zip | File:Elements.xo | Documentation | Screenshots | Videos | Browse Source

More Informations

• IRC: #elements on irc.freenode.net
• Project started by Chris Hager, March 2008. Source-Code is GPL licensed - so do with it what you want! Even eat it :)
• The Elements project derived from pymunx, which started as examples for pymunk and is growing up to a real physics api for python
• The 2D physics is handled by the chipmunk physics engine (written in C by ...)
• Communication to the chipmunk library is done via the pymunk ctypes bindings (by Victor Blomqvist.)
• A lively and open development and support team is having fun improving and helping out :)
• Features: fast, easy to use, segments, polygons, circles, colissions, variable gravity, density, mass, friction, elasticity, inertia, impulses, screenshots, screencasts, cross-platform, entertaining, fascinating, ...
• Limitations which will be implemented soon: Joints, Grouped Elements and Non-convex Polygons. Screencast encoding currently works only in linux with mencoder installed.

Screenshots

(from Elements/Screenshots)

Downloads

• File:Elements.zip (338 kb): Elements API, demos, pymunk, compiled chipmunk libs (and, for the curious, the Chipmunk sources)
• File:Elements.xo ... Demo selection bundles for the XO laptop
• svn checkout http://pymunk.googlecode.com/svn/trunk/ pymunk-read-only ... Pymunk with demos and docs
• ChipmunkLatest.tgz ... The source of the Chipmunk physics engine (written in C)

Documentations

• Elements API Documentation
• Pymunk API
• Chipmunk Docs

Examples

Examples

• demo1_ballsnsquares.py (most simple :)
• demo2_drawwalls.py (create new walls)
• demo3_addmany.py (add more objects at once)
• demo4_drawpoly.py (draw a polygon)
• demo5_draw.py (tryout for segments (buggy))
• demo6_throw_and_settings.py (++) (adjust elasticity, density, size and throw in objects)
• demo7_elasticbox.py (++) (elastic walls all around. very funny :)
• demo8_gravityfun.py (+++) (change the gravity vector (or set to (0,0) by right mouse click)

Pygame Example

The typical usage in pygame can look like this:

      import pygame
      from pygame.locals import *
      from pygame.color import *   

      from elements import *
       
      pygame.init()
      screen = pygame.display.set_mode((800, 800))
      clock = pygame.time.Clock()

      world = elements()
      world.add_wall((100, 200), (300, 200))
         
      # Main Game Loop:
      while running:
         # Event Handling
         # Maybe calling world.add_ball(event.pos) or world.add_square(event.pos)
         # ...

         screen.fill((255,255,255))

         # Update & Draw World
         world.update()
         world.draw(screen)

         # Flip Display
         pygame.display.flip()
          
         # Try to stay at 50 FPS
         clock.tick(50)