Thanks! All is working properly, the wheels are rotating, but the vehicle isn’t going to the ground and it isn’t moving. Why?
because in your physics asset your main box is to low, raise it up so that the bottom of the box is above the bottom of the kart
Great to hear it is almost working! 
If it is not dropping, that sounds like either the level’s physics are turned off, or the gravity setting has been changed… Check in your “Project settings” under the Physics tab that the gravity setting is set to the default (-980.0), and also click the “World Settings” button on the toolbar and ensure the first two options under config are checked, and under Physics, make sure “Override world gravity” is unchecked.
Don’t know if anyone else can think of any other reasons for that if that doesn’t work… You could also try creating a box large enough to drive on, and moving the player start over top of it to make sure it is not an with the landscape as well, just to test.
*Edit - GeoDav is probably right here, try scaling and moving the box in the physics asset first.
I checked all of these things and they are ok.
I tried everything with the box. I deleted it too, but the kart is fixed on the air.
Ok, got it working in my editor, the thing causing the vehicle to hover was the steering wheel physics body. Delete the sphere from that and it will drive on the ground
Make sure to re-add the box, scaled down a bit.
You may need to adjust the tire diameter in the Front and Back wheel blueprints to get the wheels perfectly aligned, but it should work. One other thing, in the wheel blueprints, set the max suspension raise and lower down to like 2, as the vehicle is smaller than a regular car, and that will cause issues as well.
Let me know how it goes, I can take screenshots of everything if need be.
I fixed it going on Constraint Mode and setting Linear Z Motion to Free to all wheels physics bodies, but there is another problem: when I go to a wall laterally, the wheels enter into the wall. Why?
scale the spheres on the wheels so that the spheres are larger than the wheel (as in not touching the wheel, but around it) and that should fix it.
*Edit - Also try changing the value in the wheel blueprints for tire width, change them both to 20, seems to work better.
Wheel bounds are ignored for collision as far as i know, so you’ll need to add additional parts to the body to cover the wheels.
Ok, thanks. Now it works.
But why the vehicle is flying? If you see the shadow, you can deduce it.
Did you set proper shape radius for the wheels?
Thanks! Now it works.
Hi everyone,
Sorry to be late on thread, and for the pain you’ve been having, though it’s cool to see everyone helping out
I wanted to mention that in 4.3 you will no longer need to explicitly set the tires to Kinematic (though leaving it as is will still work). In 4.3 a vehicle with default wheels will automatically be fixed up when it gets instantiated so it eliminates one of the steps required for vehicles.
We’re still looking to improve whole process so if you have any suggestions for vehicle specific work flow please let me know it’s great to get all feedback and see what people are having issues with.
Hi, I’m reopening thread because I got the same problem and I don’t understand why I cannot solve it.
I got my own 3d vehicle, I followed tutorial to rigg it (Setup and Export a vehicle from 3dsMax to UDK - part 1 of 5 - YouTube) but I got exactly the same problem that Scienziatogm.
I downloaded the kart that you upload on mediafire, and I it works on play mode, but if i press simulate on the physics asset, it goes crazy. Besides, I just upgrade my version of Unreal to 4.4, and now isn’t working on play mode.
So, have something changed, in relation to vehicles, on the last versions of Unreal?
with out me going into other peoples video’s the bottom line afaik is that your “root” bone of the rigg must be at 0,0,0 , if you have for any reason scaled or moved the rig/mesh the reset the root bone
ps haven’t tried much on the vehicle side due to the lack of base code, without basics like multi-wheeled / hover / copter/ flyer there not much point in me trying things of doing tutorials
As GeoDav said, make sure your root bone is at 0,0,0, but what ended up being the on the vehicle was that the root bone of the vehicle was rotated at -90 degrees on the Z axis, which seems to be the way 3dsMax places them by default. Make sure you click on the root bone (and all other bones) one at a time, switch to the ROTATE gizmo, and ensure the x/y/z values in the boxes below the viewport are all at 0.0, you will most likely see that Z = -90.0.
The other thing to make sure, is that your model is facing towards “positive X”, basically click on your mesh, and make sure the front of the vehicle is pointing in the same direction as the X (red) axis arrow.
The reason the Kart goes crazy is because of the extra physics asset attached to the steering wheel, which throws everything off for some reason, so if you have a steering wheel either delete that bone, or make sure in the physics editor that there is no sphere or capsule body attached to the steering wheel, delete it if there is and try again. If you want to have a steering wheel that you can animate, you can use a separate mesh for the steering wheel, and link it to the vehicle body, as detailed below.
The bone system is no longer necessary either for anyone reading , all you need is your vehicle mesh, and 4 separate wheel meshes. In 3dsMax, once everything is lined up correctly, “link” (top left button in toolbar) each of the wheels to the vehicle mesh one at a time, and you are done. Export the vehicle mesh (which will also export the wheels, as they have been linked) and perform the same setup in UE4 as usual.
Let me know if you need more info!
My root bone is at 0,0,0 and now the orientation is ok, but is what’s happening:
The blueprint (I added some logs):
On the game, as you can se on the log of the screen, I’m pressing forward, but my car is not moving. I got the same config for the crash bandicoot kart, and is working well, what is happening with my Batmobile?
thx for the responses
Have you set the Wheel blueprints and the Animation Blueprint?
Why didnt you plug axis value to throttle?
I’m following the unreal tutorial (https://www.youtube.com/watch?v=9ariPx6M33o&list=UUBobmJyzsJ6Ll7UbfhI4iwQ) wich can move the car without Wheel Blueprints and Animation blueprint (of course, I don’t expect rotation or movement from wheels, just movement from the car body)
Because the tutorial does it in that way
My mesh is kinda big, so I also lowered the mass scale of the mesh, but I still don’t get it working