the setvelocity is a trick one because the direction values change in different directions e.g
asic velocity
[X,Z,Y] this is just how the numbers are arranged so facing north (default compass direction , 0 ,the command
this setvelocity [10,10,10]
would send the vehicle 10speed to the right, 10 speed forward and 10speed UP whereas
this setvelocity[-10,-10,10
would send it 10speed to the left, 10 speed backwards and 10speed up
though take in mind using a - number for the verticle would send the vehicle crashing down (if its in the air, and sometimes when its not) to earth and a bug that if you set the verticle too HIGH it hits the ground and gets destroyed, i dunno why that happens though
Guide to the Directions Setvelocity send the vehicle , relative to vehicles Azimut Heading
FACING NORTH
Y=Verticle* a normal # is UP a -# is DOWN
Z=Forward/backward, normal # is FORWARD, a -# is BACKWARD
X= -Left/+Right (-# is LEFT: normal # = RIGHT on vehicles facing north)
FACING EAST X with a normal # is forward X with -# is backward: Z with normal # is LEFT, Z with - # is RIGHT
FACING WEST
X with a -# is FORWARD X with normal number is BACKWARDS:Z with normal # is RIGHT, Z with - # is LEFT
FACING SOUTH
Z with a -# is FORWARD, Z with normal # is BACKWARD: X with a -# is RIGHT and a normal # is LEFT.
hope that helps the people who wanna use setpos
N.B
* means that it is a constant, no matter which Compass direction the direction this sends the vehicle remains the same
-# = A MINUS NUMBER E.G. -100
normal # = a positive number e.g 100
[X,Y,Z] replace any letter with a number
hope that helps but its still tricky