Two Source Interference Pattern in 3D

Here is an interactive animation that demonstrates the motion of a surface overwhich two circular periodic waves interfere. Instructions and information below.





Much of the explanation and mathematics for a two source interference pattern is contained on another page, Two Source Interference Pattern in 2D. On this page we see the same type of interference pattern shown here with a three dimensional mesh representing the vibrating surface.

Click this button to see the instructions for the demo:

Instructions Click the button again to remove the instructions.

There are controls to the right of the animation. You set values and conditions by clicking on the controls with your mouse or tapping with your finger.

Numbers are adjusted with the buttons labeled with less-than and greater-than signs:

  • << Means make the number much less
  • < Means make the number a little less
  • > Means make the number a bit greater
  • >> Means make the number a lot greater


All of the controls for the wave are in yellow. Here are their meanings:

  • λ - lambda, or wavelength.
  • f - frequency
  • A - amplitude

Important: Wavelength and frequency adjust independently in this demo. That means that changing the wavelength will not cause a change in the frequency.


All controls for the sources are in white. With them you can:

  • Turn each source on or off using the checkboxes labeled '1' and '2'.
  •  Make the two sources oscillate in phase or in opposite phase.
  • Move the sources to the middle or to the edge of the surface.
  • Change the distance between the sources, called d.


All controls for the 3D viewpoint are in blue. Use these to change the position from which you view the surface. Two of the controls rotate your viewpoint around the surface, and the third controls your viewing distance from the surface:

  • θ - Theta, rotates the view around the surface about an axis
  • φ - Phi, rotates the view around the surface about a different axis
  • ρ - Rho, moves the view in close or far away from the surface