Multi body vehicle, is it possible?

ey up

after much testing and messing i cant make it work.
if i add any joints in the vehicle physics asset the wheels no longer work and the car will not drive.
also the body attached to the joint (a door for example) pings to 0,0,0 in the car as soon as the game starts, kinematic, collision on or off doesnt matter.

i found this and Ori mentions multi body vehicles being in the engine (4.2)

there some hidden tick box somewhere or something or did this not make it in at all?


bump :slight_smile:

as with many things in this engine, its difficult to tell if im doing something wrong or the engine cant do what i want or that particular bit of the engine is broken.
anyone know anything at all about this?


looks like a bump to me

flappy bits on a car?

Have you looked at this downloadable project, should be of interest to you if you havent already seen it

thanks for the reply, not quite what im after though.

just the normal built in wheeled vehicle with more than 1 physics body, can it be done?

Well you can add objects that simulate physics to the vehicle but it usually turns out pretty extremely badly, I have used blueprints to alter the mass settings of the other objects depending on the vehicles movement to keep it from going haywire, like say I added a character mesh riding the car like a skateboard, but to have physics enabled on the player mesh I had to constantly alter the mass and gravity settings with blueprint, but it worked


this is my experience too. dont fancy having to constantly alter the mass and gravity.
adding other actors though is another thing altogether.

basically what im trying to achieve is almost a ragdoll skeletal mesh with hinges and the like that i can break on impact using the standard wheeled vehicle class.
the trouble is, any joints at all in the physics asset somehow disable the wheels and the car wont move.
also any settings in the joint, free, limited ect, are ignored and that part of the mesh pings to the center of the car on game start.

I would recommend contacting ori cohen or someone similar involved in the actual vehicle coding if you already haven’t, there may be a very simple way to get it to work and the vehicle components are pretty esoteric at the best of times…or ask xenome who made the advanced vehicle template, also have you seen xenomes original vehicle that got him contracted to make the advanced vehicle template, its very cool, a real pity that it isnt the adv vehicle template

I have had hinged panels that flap around on the side of the vehicle, is this similar to what you are going for? Because I just added an extra joint, connected to the root, and skinned it to the panel. Then in phat, I just shrunk the joints collision really small so it wouldn’t interfere with the vehicle while simulating. Not sure if that is anything to help!

I spent about 3 months on vehicles in UE4. First of all UE4 only supports 4 wheeled vehicles. NVidia PhysX has a class PxVehicleDriveNW, but it is not implemented in UE4. For that, you have to write your own C++ classes including animations etc, which would be a tough job. If you want to make a long vehicle with a trailer (both of them 4 wheeled) you can design them separately.

thanks yes this is what im trying to do but with doors and bonnet ect.
even with a single joint and very small collision in phat the wheels of the car no longer work. they sink into the ground.
what version did you do this with docjor?
im trying on 4.8.3 because 4.9 just freezes all the time.

I have it working in 4.8, have not ported to 4.9 yet so I can’t test that one for you just yet. I usually find whenever I get the wheels sinking into the ground that it is usually because of either the wheel setups being wrongly named, or less / greater than 4 in the vehicle movement component in the vehicle BP, or something messed up with the wheel / root joints / collisions.

That being said I’m pretty sure 4.9 came with a newer version of physx, so there might well be a brand new limitation there… hoping not.