VPython applications for Teaching Physics

Content from the original site https://web.archive.org/web/2001*/http://physics.syr.edu/~salgado/software/vpython/ is slowly being copied here.
Some links may be broken... but they will be fixed soon.

current academic homepage: Rob Salgado
up to: visualrelativity.com

last updated 10/31/2015 ( prev update 9/27/2011 ) created Dec 8, 2001 (at Syracuse)

Tinkering...

Rob Salgado's GlowScript programs
More about GlowScript
For Browsers that support GlowScript, view the GlowScript documentation

Soon

VPython-with-the-Wiimote files mentioned at AAPT09Sum-AnnArbor.
EXAMPLES ARE NOW AVAILABLE
Some reorganization of this page.
Some reogranization of URLs to other websites. (If you have a site to suggest, send me an email.)

What's Was New

(07/16/2008) - accelerometer example posted
(06/20/2008) - IR-headtracking example posted
VPython with real-time data - [Rob Salgado and Tav Hawkins]
with the Wiimote, the Go!Motion, NeatTools-and-TNG-3B, ...
Most of these programs have been tested on Python 2.3.4 / VPython-Py2.3.4-2003-10-05b.exe I am trying to gradually update them to work with the newer versions. If you have made any upgrades, please share them with me.

How to run these Python programs

These python programs (pythlets?) are written in Python with the "visual" module VPython, which provides real-time interactive visualization in 3D.

You can download the current version of VPython here and read about its development at the visualpython-users mailing list.

The older Python-2.4/VPython-3.2.9 version is here (local copy: python-2.4.1.msi and VPython-Win-Py2.4-3.2.9.exe).

Here is a local copy of the even older version (local copy: Python-2.3.4.exe and VPython-Py2.3.4-2003-10-05b.exe).

Waves

   wave_superposition.py tested with VPython23-2003-10-05

   doppler-wavefront.py tested with with Python-2.3.4.exe and VPython-2003-10-15.exe

Kinematics

   2D-kinematics-with-vectors.py tested with VPython23-2003-10-04
   2D-kinematics-with-vectors-circular.py tested with VPython23-2003-10-04
   2D-kinematics-with-vectors-circular-polar.py tested with VPython23-2003-10-04

1D-kinematics.py tested with VPython23-2003-09-04 1D-kinematics-with-vectors.py tested with VPython23-2003-10-04 1D-kinematics-with-vectors-alt.py tested with VPython23-2003-10-04

Electromagnetism


   EFieldBuilder-09990.py (v0.9990) tested with VPython-2003-10-05.exe
   EFieldBuilder-0997-22.py (v0.9972) requires VPython-2001-12-31.exe
   EFieldBuilder-0997.py (v0.997) requires VPython-2001-10-31.exe
   EFieldBuilder-0996.py requires VPython-2001-10-31.exe	
   EFieldBuilder-099.py


   Maxwell-Gauss-Coulomb_v275.py tested with Python 2.3/VPython-2003-10-05.exe 
   Maxwell-Gauss-Magnetic_v275.py tested with Python 2.3/VPython-2003-10-05.exe


   Maxwell-Ampere.py (v2.52) tested with VPython-2001-10-31.exe
   Maxwell-Ampere_v275.py tested with Python 2.3/VPython-2003-10-05.exe (includes change in color scheme) 
   Maxwell-Ampere_v276.py tested with Python 2.4/VPython-3.2.9 (includes change in color scheme) 



   Maxwell-Faraday.py (v2.52) tested with VPython-2001-10-31.exe
   Maxwell-Faraday_v275.py tested with Python 2.3/VPython-2003-10-05.exe (includes change in color scheme) 
   Maxwell-Faraday_v276.py tested with Python 2.4/VPython-3.2.9 (includes change in color scheme)


   EMWave-020110.py (v0.5) tested with VPython-2001-10-31.exe
   EMWave-030216.py (v0.51) tested with VPython-2001-10-31.exe
   EMWave.py (v1.00) tested with VPython-2003-10-05.exe
   EMWave-Maxwell.py (v2.51) tested with VPython-2003-10-05.exe
   
   EMWave-Maxwell_v275.py tested with Python 2.3/VPython-2003-10-05.exe (includes change in color scheme)
   EMWave-Maxwell_v277.py tested with Python 2.5/VPython-3.2.11 (Thanks to Martin Mason for changes needed for Python 2.4+.)
   EMWave-Maxwell_v280.py tested with Python 2.6/VPython-3.2.11 (fixed bug with scene.ambient [2015-10-31])


Under development: VPython projects (led by Rob)

Relativity

Visualizing Proper Time in Special Relativity

Tensor Calculus and Differential Forms

(under development)

This demonstrates the addition of two covectors (two "1-forms") via the "co-parallelogram rule".

A_a + B_a = C_a

(2008) VPython with Real-Time Data [with Tav Hawkins]

(06/20/2008) VPython with real-time Wiimote data (head tracking with the IR-camera)

headtrack-Wiimotelib121-PY24.py
tested with Python 2.4/VPython 3.2.9

The inspiration for this project came from the efforts of Johnny Chung Lee - Projects - Wii.

In order to read in the real-time data from the the Wiimote, we use the procedure presented by Nishio Hirokazu, which uses Brian Peek's (Windows-only) WiimoteLib v1.2.1 [a library for using a Nintendo Wii Remote (Wiimote) from .NET.] described in "Code4Fun - Managed Library for Nintendo's Wiimote (Brian Peek)". To use .NET with Python, we used Brian Lloyd's Python for .NET.

Ideally, we would have liked to use the latest versions of the various software packages [which should be possible]. However, for now, the combination of versions that worked for us [with our program] is:

I'm sure there is a platform-independent solution in which Python communicates directly with Bluetooth. Of course, one now needs to know details of the protocol for talking with the Wiimote.

Note: This was just thrown together as a proof of concept. The code isn't the prettiest. The tracking and the visualization could certainly be improved.

Some Hardware details: I bought two LED-flashlights (less than $5 each) and replaced the LEDs with IR-LEDs from DealExtreme. I mounted the flashlights onto a pair of safety goggles. (The first version is pictured here.) The Wiimote is sitting on top of my monitor, pointing toward me. [Note, I only use the Wiimote. I don't have a Wii console.]

My current version uses IR-LEDs from Radio Shack [which seem to have a better viewing angle] and two MAGLITE Solitaire flashlights [found at Walmart] which feature replaceable LEDs. So, no soldering is needed! However, since my standard-size LEDs were too big, I had to leave off the moveable mirror/cover used to adjust the beam.

If you don't have these IR parts available, you can try using a pair of standard (IR-based) remote controls. By the way, it's helpful to use your typical webcam or cameraphone to see the IR light to check that the LEDs are hooked-up correctly.

NEW! (07/15/2008) VPython with real-time Wiimote data (3-axis accelerometer)

accelerometer-Wiimotelib121-PY24.py
tested with Python 2.4/VPython 3.2.9

After pairing your Wiimote with your computer's Bluetooth radio, your Wiimote's three-axis accelerometer readings are represented by an arrow.

(Think of the accelerometer as "a small sphere suspended by identical springs attached to the corners of a cube".)

When your Wiimote is sitting normally upright on your desk, it will read a_z=1. (The small sphere is displaced downwards, and the net force on the sphere due to the springs is upward.)

When your Wiimote is in freefall (and not rotating), it will read zero. To show this, gently toss (without rotation) your Wiimote to someone. When the accelerometer value is small enough, the background color of the scene changes to white (since the corresponding small arrow is hard to see).

VPython with real-time Vernier Go!Motion data (ultrasonic ranger)

(soon)
VPython with real-time data with NeatTools and Mindtel TNG-3B

(soon)

VPython with the Wiimote

(based on our presentation at AAPT09Sum-AnnArbor)

(more information will be added to this section)

This is an update of our earlier version [for Python 2.4 / VPython 3.2.9 / WiimoteLib 1.2.1 / Python for .NET 1.0 ] from above.

For Windows XP and Vista... (checked with XP SP3 and Vista64)

Download and install Python 2.5 and VPython 3.2.11 (You can also try Python 2.6 and Visual 5. I haven't tried "Python 2.5 with Visual 5".)
To get data from the Wiimote, you need Brian Peek's WiimoteLib library using .NET (which is the library used for Johnny Chung Lee's Wiimote projects, as well as many others).
The latest stable version is WiimoteLib 1.7.
(Alternatively, for partial support of the Wii MotionPlus extension, try WiimoteLib 1.8 beta.)

The only file you need from the downloaded package is WiimoteLib.dll.
(It is helpful to also use WiimoteTest.exe to see all sorts of data from the wiimote.
You'll find documentation for the library, WiimoteLib.chm, in the docs/ folder. )
To get Python to talk to WiimoteLib, you need Python for .NET 2.0, which provides clr, an interface to the .NET Common Language Runtime.
Unfortunately, the file pythonnet-2.0-alpha2.zip only works for Python 2.4.
Fortunately, Feihong Hsu figured out that one can compile the Python for .NET source code and tweak switches to make it work in Python 2.5 and in Python 2.6. In the end, all you need are the two files Python.Runtime.dll and clr.pyd placed in the Python folder (e.g. C:\Python25 ).
- for Python25:
  Feihong Hsu saved us the trouble by putting those two files in a single .zip file: http://feihong.hsu.googlepages.com/PythonNET2.0.zip
  Here is my local copy of his files. You can get the .zip archive, or the files separately:
  PythonforNET_compiled_forPython25.
- for Python26 (with VPython 5):
  Here are my files (compiled according to Feihong Hsu's instructions):
  PythonforNET_compiled_forPython26
In summary:
- In your Python installation folder, Python.Runtime.dll and clr.pyd.
- In the folder with your Python program, WiimoteLib.dll.
VPythonWiimote-examples.zip contains some example programs (including the required library files mentioned above). (Tested for Python 2.5/VPython 3.2.11. Some modifications may be needed for Python 2.6 or for Visual 5.)
Possibly useful: flexible tripods
...to be continued

[more to come!]

VPython applications (up)

Programming Notes

Using Python 2.3

Here's a registration-file for Windows 2000 and Windows XP that will fix that problem with the IDLE editor closing completely when terminating an animation you are working on. Python-File-new.reg It assumes that you installed Python in the C:\ drive. If so, you may just "Open" it. Otherwise, download [Right-click->Save Link to...] the appropriate pair to your desktop, then after reading the .reg files and making any desired changes, merge with your registry. Then, "Merge" it by double-clicking on it.

Python-File-new.reg

If you mess up, you can try to clean things up in Explorer via Tools->FolderOptions->FileTypes...->PY Python File->Advanced
..or else use regedit.
Use at your own risk! (Backup your registry before merging!)

Using Python 2.3 and Python 2.4

These registry hacks to allowed me to select which VPython version is used to execute a .py file. They may work for you.
Use at your own risk! (Backup your registry before merging!)
Download [Right-click->Save Link to...] the appropriate pair to your desktop, then after reading the .reg files and making any desired changes, merge with your registry.

My Python installations are on the F:\ drive: