VLATI-VIS

VLATI-VIS is the visualization and animation program for VLATI. It’s capable of animating each body’s trajectory over time, using different origins, and speeding up the simulation with a certain multiplier.

Syntax:

VLATI-VIS [-h] [-f FRAME] trajectory_file start_frame end_frame multiplier

The multiplier is applied to the index of the trajectory arrays, so it applies to the start and end frame. For example, if you use t=200 as the start frame and 300 as the multiplier, the first frame will be t=60000. The same applies for the end frame.

The multiplier argument can be followed with an x, or alternatively nothing.

The --frame/-f argument can be used to change the inertial frame of the visualization. For example, for the Moon to be at the center of the visualization, use -f moon. This is case sensitive; as such, all frames must be lowercase.

If you’ve added a body to VLATI, its trajectory needs to be exported to the .npz file in order to be used in the frame argument.

Examples

Play the trajectory from output.npz at 200x speed, from frame zero to 500000 in an Earth-centered inertial frame:

VLATI-VIS output.npz 0 2500 200

Play the trajectory from output.npz at 100x speed, from frame 200000 to 500000 in a Moon-centered inertial frame:

VLATI-VIS output.npz 2000 5000 100x -f moon

Play the trajectory from output.npz at real speed, from frame 0 to 180000 in a spacecraft-centered inertial frame:

VLATI-VIS output.npz 0 180000 1 -f sc