lightspeed (1)

lightspeed [-hsa] [object]

Light Speed! is a simulator which can illustrate the effects of special relativity on the appearance of objects travelling at ultra-high speeds. Depending on the particular speed, and one's point of view, relativistic effects can cause the object to appear shorter, longer, brighter, darker, deformed and/or off-color.

To adjust the velocity, use the slider along the right edge of the main window. You can also type in a value, using the entry at the top right (press <Enter> once it is in). To change the units shown, press the button to the right of the entry, and it will cycle through a small list.

The object travels in the positive-x direction, which can be visually checked by activating Objects -> Coordinate axes.

Most interactive control is performed with the mouse. By holding down a particular button, and dragging the pointer around, various camera motions can be obtained:

   Left button:  Revolve camera around view target

   Left button + Shift key:  Revolve view target around camera

   Middle button:  Translate camera left, right, up or down

   Right button:  Dolly in or out

The first and last motions are generally the most useful. Should the camera become difficult to control at any point, it may be re-initialized by selecting Camera -> Reset View.

-h, --help

Print this help screen

-s, --simple

Use simplified interface

-a, --advanced

Use advanced interface (default)

object

3D file to load on startup (.3DS or .LWO)