This applet attempts to simulate what would register on your 3-d retina if you were viewing the edges of a 4-d polytope.

The axises are oriented so that w is directly into the screen, y is to the left, z is up, and w is the other way.

You have three basic mouse controls: drag the mouse with the first button held down, drag the mouse with the second button held down, and drag the mouse with the third button held down. (If you do not have a 3-button mouse, you can use the first button while holding the shift key to simulate the second button and the first button while holding the ctrl or alt or meta key to simulate the third button.)

Dragging with the first or second mouse button rotates you around the polytope. Dragging with the first button left to right rotates you parallel to the xy-plane. Dragging with the first button up to down rotates you parallel to the xz-plane. With the second button, dragging the mouse left to right rotates you parallel to the yw-plane. Dragging with the second mouse button from up to down rotates you parallel to the xw-plane.

The third mouse button rotates the whole 3-d retina to allow you to see exactly which portions of the retina are stimulated. With the third button down, moving the mouse left to right rotates the retina in the yw-plane. With the third button, dragging the mouse up to down rotates the retina in the zw-plane. When you release the third button, the retina snaps back to its default orientation.

The "Reset" button resets the polytope to its default position/orientation.

The scrollbar on the right of the applet scales the views. Note: it does not move you closer or farther away, it merely zooms the view.

The source code is in the jar file.