# Golf ball physics

I’m working on a scene where golf balls land on a driving range and I’m having trouble getting it to look right.

When the balls land they roll in an unrealistic way - it seems they lose energy in a linear fashion where as I guess to look right they would need to move increasingly slowly before coming to a stop.

I’ve tried using different physics materials (seemingly no effect) and high sleep thresholds (stops the ball suddenly when a low speed is reached). Playing with the linear and angular damping helps a bit but slows the ball down mid air and, with the angular drag set high, on a shallow slope the balls roll at a constant low speed as if rolling over honey.

Wondering if there were any known solutions or workarounds for this?

For the mid air, use your own ball ‘trajectory path’ instead of relying on the ball physics.

Thanks - no problem with the airborne part however - it’s just getting the balls to come to a standstill on the grass in a way that looks believable that’s tricky!

I think syed meant have a separate system for when the ball is flying, then use the physics you want after it’s landed.

You can create your own dampening system in blueprints. In other words you can have different dampening for when it’s mid air and then once it’s landed.

Ah right - yes, sorry, I see!

I think I’ve got it working - may be of use for anyone coming across this in the future. The ball tests its linear and angular velocity and once both these are below a given threshold it triggers an increase in both linear and angular damping (using finterp to bring them up). This lets the balls land and roll around as expected but then slows them down quickly once they lose a certain amount of energy so they look like they are rolling on grass rather than a smooth surface. Looking up close however it still looks a bit odd because the damping never works quite right…