Help Better Understanding Physic Joint Properties | Forums

[rlmergeuser]

For the track I'm making, I'm hoping to have many instances where the rider makes contact with another object. As someone else in another thread pointed out, objects that have contact with the rider are achieved by using a physics joint whereas OPEs are for movement only and no contact. So, listening to that advice, I am trying to get more familiar with how Physic joints work. I've used physic joints before in other tracks but only by messing around with the different values. I don't want to mess around though. I want to know what these values that I am messing around with actually do in relation to the object. I've watched the Trials Evolution Editor videos by Cannibal Shogun (specifically the one about Physics Joints), which were helpful to some degree but for the most part, I have no idea what the values actually do in relation to my object.

For the description of linear setting values, it says "Limit Movement. If you set the upper limit lower than the lower limit, movement is not limited."
Then for Angular Setting values, the description says " Limit Rotation. If you set the upper limit lower than the lower limit, rotation is not limited." I keep reading that and saying to myself, "Okay, what does all this mean?" If somebody could provide a better explanation or example or perhaps a demonstration of such properties, I think that would really open up the possibilities for myself and many others. I know I can't be the only one having trouble comprehending what these property values actually do.

[Lukeyy19]

I'm going to start off by saying that Physics Joints are not really my strong suit, I still have trouble getting them to work exactly how I want. but this is my understanding of it all. First off, anything that says Linear relates to up/down and side to side movement, and Angular relates to rotation movement.

The movement limit is the amount the joint will move in either direction, so if you set the angular lower limit to -90 and the upper limit to 90 the joint would rotate from -90 degrees to 90 degrees giving it 180 degrees of movement, if you set the lower limit higher than the upper limit (a physically impossible set of values) then there is no limit and the joint will just spin all the way around.

The softness of the joint is how easy it is to move, a high softness value will mean the joint reacts less to a force being applied on it, so if you had a wall on a slider joint, with a high softness value when the bike drove into the wall it would take more force to push the wall back, but with a low softness the wall would be easier to push with the bike.

Restitution relates to how the joint reacts once it hits it's limit, and is basically how much bounce the object has, except a larger value will mean it will bounce off the limit less than a lower value will, so if you want something to fall, hit its limit and stop, then you want a high restitution.

The spring setting is how much the object will try to push itself back towards it's starting position or first pivot point, a higher spring setting will equal more force.

Without looking at the editor this is all the options i can remember but if you want any more advice then just direct me to a specific setting and i will try to explain, or i'm sure somebody else will.