Animator: Script Example 10

Doppler

Reinitialize

The Doppler object is a subclass of the Circle object that can emit wave crests at a predetermined rate.

document.animator.addObject("doppler","r=10,c=1,n=20,period=1")

The following parameters are define for the Doppler object:

• r    the radius of the object
• c    the speed of the wave crests
• m   the mass of the object
• n    the maximum number of wave crests displayed at any one time
• period    the period of the source

Doppler objects, like all other geometric shapes, can be made dynamic using the setForce method.

NOTES: 

• The Doppler object is non-relativistic.  It is possible for the speed of the Doppler object to exceed the phase velocity.
• The time step, dt, should be less than the 1/10 of the period.
• Wave crests will take on the color of the Doppler object.  Create a second object and slave it to the Doppler object in order to create a different color.