I haven't seen any recent tutorial explaining how to do it, they were all mostly broken so here it is:

1. Make sure the ground is dynamic with fixed rotation and no mass.
2. In the XML add a <L></L> tag between the final <O/> and </Z>.

For example:



Becomes:



3. In between the <L></L> tag, add two <JP M1="1" M2="0" /> tags.

4. Each tag has to have M1="Z value of the treadmill ground" and M2="Z value of a static ground on the map".



In this XML the 0 is the Z value of the treadmill ground and the 1 is the Z value of the static wood ground above it.

5. Add MV="Infinity,-20" to the first JP tag. (You can make the 2nd value even lower, like -30 or -40)



6. Then add an AXIS value in both JP tags.

In the first tag you add AXIS="1,0" if you want the treadmill to shoot you to the right. If you want it to shoot you to the left then add AXIS="-1,0".

In the second JP tag you just reverse the AXIS value, which gives you AXIS="0,1" for the first example or AXIS="0,-1" for the second one.



Note: increasing the friction increases the strength of the treadmill.


Also I'd like to thank Physcolo for his help to make this(better enligsh than mine yes).