Why won't my wheeled vehicle move?

So, I seem to be only person who has run into this problem, but no matter how many times I replicate the “Overview and car setup” Tutorial (Found here: https://www…com/watch?v=9ariPx6M33o&list=PLZlv_N0_O1gaz6eETtIxcmUDnqu5A-8At&index=1 ) My vehicle pawn refuses to move. I’m using a project I built from the “first person shooter” template, and eventually I want to learn how to let players “possess” a vehicle pawn. But right now I can’t even get things to move, at all.

I’m using Blender but I have my Axis and scale correct, as far as I can tell…

I’ve run game with blueprint in view, and it seems as though nothing in blueprint fires, at all, no matter how desperately I press move keys :frowning:

Hey ,

When you hit Play, are you selecting your 4WheelTest_BP in Debug Filter to see it in action? If not, definitely do that to make sure your InputAxis nodes are actually firing.

If they are still not being activated, it’s possible you don’t have input enabled on your vehicle. Under Defaults, make sure that Block Input is not enabled. You can also choose to set Auto Receive Input to Player 0 for testing, though it sounds like that wouldn’t be appropriate for your project.

last thing is to make sure that you are possessing vehicle in play. You can set 4WheelTest_BP as your Default Pawn Class under World Settings > Game Mode. If you’re looking to have your character get into vehicle from a First Person character, you will need to possess vehicle before those InputAxis nodes will register.

If you’ve done all those things, would you mind describing or showing us your possession setup? Thanks!

Just wanted to add that I’m also having same issue.

Debug filter shows axis are being passed on to Throttle inputs and steering.

Possessing using Default Pawn in World Settings, and also through new GameMode as per Vehicle Setup guides instructions. Also tried Auto-Possess in Default settings, as well as Auto Receive Input (double checked that Block Input was off).

In game, wheels spin as well as turn left and right with correct controls, but vehicle does not move.

Tried this by placing vehicle on top of a mesh with collision, and also in a brand new level using a box brush.

Hey ExP,

If you use Mesh provided in video tutorials instead of your own, do you run into same issues? You can download Mesh here:

So, I was able to get SK_Car to work perfectly fine and according to tutorial. Using exact same method I used for my own vehicle. only real difference, as far as I know, is that mass of my vehicle is significantly greater. However increasing torque didn’t seem to change anything. My vehicle still just sits there.

I’m including my test vehicle that is approximately same size and weight as my actual full detail vehicle, both are having same issue. If you import it with same settings as SK_Car, it wont work for whatever reason.

And to answer first questions: Everything is setup way you described, though I currently don’t have a possession setup, I was simply having game load blueprint by default. Which worked when I used SK_car.

link text

Hey ,

I downloaded mesh, skinned it in Max and went through vehicle setup guide again. After all was set and I hit ‘Play,’ my car rocketed into air in most chaotic way possible. Kerbal Space Program would have been proud.

After fidgeting with it for a while, I decided to scrap it and skin it again entirely from scratch. It worked perfectly second time and I got car to drive around just fine.

I’m not really a rigger, but only difference I know about between first and second time was cheapening out first time by creating one wheel bone, and then duplicating it for other three. This second time, I made all individual. Could that have been it?

And while it works perfectly fine in Play, when I hit “Simulate” in Physics Assets window, car goes flying. Is this normal?

(Although it won’t do that if I change wheels’ physics to ‘Default’ instead of Kinematic, but then in Play wheels are left behind; I assume this part is working as intended?)

I’ll re-skin my actual car mesh tomorrow in Max and get back to you in case it was just an issue there.

Thanks for help =) And apologies to for sort of hijacking this.

Hey ,

Just wanted to update you to let you know that we are seeing same problem with your mesh, and are digging into what cause is. I will let you know once we have it sorted out. Thanks for your patience!

No problem, it may be important to note that I am using Blender for modeling of these (since $185 a month is way more than I’m able/willing to pay for 3DS Max. Like, maybe if I was doing this professionally, but nope)

Okay, after creating FrontWheel and BackWheel blueprints, I was able to get car moving. Have you reached that part of tutorial yet?

Additionally, your SkeletalMesh’s wheels are all aligned to wrong axis. You want to make sure your wheels are facing forward along X axis same as your car’s body. To see what I mean, open up your SkeletalMesh and open Skeleton tab. Under Skeleton Tree panel, click Body. You’ll see Red arrow pointing forward. Now click on one of wheels, and you’ll see arrow pointing to left. You want all to be pointing forward, same as Body.

Let me know if you get your car moving after setting up and assigning FrontWheel and BackWheel blueprints.

Okay, so I did all of that just now, fixed orientation of all axis (though now I feel dumb for missing it first time) and set up both back and front wheels. They spin, front wheels turn. But my vehicles STILL just sits there. As if movement inputs are not what they say they are. Yet SK car works fine… besides fact that it now seems to be unable to turn right…

Would you mind uploading your adjusted mesh? Thanks!

Wooow… okay, nevermind. I seem to have fixed it based on a hunch. bottom of hull of vehicle was at 0,0,0 in Blender. I noticed this and thought “Hmm… that doesn’t seem quite right, maybe it’s causing constant collision with ground” AAAAND YES that’s exactly what seems to have been happening. Thank you very much for assisting me in this painful process that reminds me why I spend most of my time on environments, haha.

In case you want to see what a slight difference there was… link text

ONE MORE THING. I was almost right. center point of each wheel collision mesh needs to be below collision bounds of body mesh. If your vehicle looks like it should be working but is standing still, lower Z offset of each wheel bone in blueprint, where it asks for wheel bones. This was problem all along for me.

Sorry, another related subject has come up.
I was comparing between my original 6-wheeled LAV model, where I originally had this problem, and my 4-Wheel test vehicle. For whatever reason, creating a vehicle with two extra drive wheels causes vehicle to be unresponsive. So far I don’t see anybody having an answer to this problem. Is it simply not supported?

Hey ,

Would you mind opening a new question regarding your 6-wheeled vehicle? That way we can separate out two different issues. Thanks!

I have same problem now (same tutorial). I can do tutorial in my sleep. I set everything inclusive front- and backwheel blueprints. forward/right axis event red lines are moving in debug filter. I made 2 skelletons. In one skelleton my wheels finally spinning (animaionBP) and I can steering L/R, but car is still not moving and wheels are half in floor. All axes shows in right direction inside UE4. I used Cinema 4D for rigging. I changed physAsset many times. (Car exploding, kinematic settings ect.) I don´t know what I´m doing wrong? Is there any setting I need to do that car has another value when I press “play” Also block Input is disabled" Does wheel bones has to be connected with main_bone? On first picture it´s inside my suspension bone: https://onedrive.live.com/?cid=EB6441E991262961&id=eb6441e991262961!400

For all Cinema 4D users. You have to set Z axis to minus, also into floor. For me it was X 0° Y -90° Z 0°. It not has to be on 3D object itself. But root_bone and wheel_bones should be set correctly:

Took me lot´s of days to figure this out. Hope this answer is helpful.

Well, to add my 5 cent, my problem was describe above, wheel centers may not be inside body volume, thx again guys, solved, i like this place here :slight_smile: :slight_smile:

This problem also kept me pulling my hair. wheels where turning but no movement of car. I was missing this piece of information that pivot of Car body needed to be lower than pivot of wheels. I linked meshes to each other. and this pivot is position of root bone.

Just posting here for visibility.

vehicle also needs (at least) 4 wheels.