This simulation demonstrates the three dimensional vector field of charged particles. Within the coordinate cube a periodic array of arrows of uniform length displays the local field direction. The field strength is indicated qualitatively by color gradation, with blue for high, green for low values.
The default situation positions two particles of opposite polarity symmetrically to the origin in the xy-plane (z = 0). The particles can be drawn with the mouse, while one sees the resulting change of the field. Reset leads back to the default position.
The 3D projection can be rotated and tilted by drawing with the mouse into any arbitrary position. The perspective radio buttons generate well defined views
By means of the slider test plane a yellow plane parallel to the xy plane can be shifted in the z direction. It hides all arrows below, and thus allows you to observe cross sections of the field. This is most effectively done in the xy view, with or without perspective.
The arrow length slider changes the length of the direction indicating arrows, the supressed levels slider defines the number of field levels that are shown. These two parameters help to select a clear visual display.
The polarity button switches between equal and alternating polarity of particles.
The number of particles (default 2) can be written into the field number of particles. Initially all particles will be arranged symmetrically along the periphery of a unit circle, alternating for nonequal polarity. Each particle can be drawn with the mouse to any position. This way an unlimited number of geometric arrangements is possible.
The origins of the arrows are positioned periodically. This leads to visual pattern artifacts when one looks along a symmetry plane (similar to looking into the model of a crystal lattice). They occur more frequently the denser the array is. The chosen array of 16*16*16 points is a reasonable compromise.
The 3D effect is most impressive when the 3D projection is slowly rotated with the mouse.