Wheels collision boxes are offset

Hi, I’m working on a simple vehicle from Blender and imported with FBX format. My vehicle PB are done, but there seems to be an issue with the wheels collision boxes position. Here is a screenshot:


What you see is a pxvis collision image. The black things in the middle are my wheels collision boxes (4). as you can see they aren’t matching my wheel setup at all. They form the right shape but not the right size (I guess). I don’t think this is an import issue because the mesh and the pink collision box are ok. Even though the wheel boxes are offset, my vehicle run perfectly. Also in my wheels setup, I did not touch the offset value on any axis for my wheels:

Compare my wheels setting

Also, the parenting is correctly done in blender between the wheels and the chassis
What did I do wrong and what should I do?

Quick question- where did you generate your collision meshes? In Blender or in UE4? Also does it look like the collision meshes are oriented and sized correctly relative to each other, just not to the rest of the world?


I made them using UE4. The collision meshes look good and are well sized. My point is, would this be because I imported my non-scaled mesh before reimporting it ten times bigger (scaling it in Blender)? Also, I forgot to mention that my wheels do not collide with the world even though they have a collision box. only the black boxes and teh chassis interract.
Here is an image that shows more what happens:

this is what I would like to fix. My four wheels are clearly touching the ground but it does not affect my car (even though they are spinning) and the weird black boxes are in mid-air.

I doubt it happened because you reimported the mesh (unless you need to apply the scale in Blender), but you can certainly try importing it as a new object just to see, who knows! And I’m confused then, what exactly are the black boxes? Are they collision meshes you intended to create, or did you intend to create the pink ones around the wheels and these rudely popped up uninvited?

Sorry I’m not being more helpful here, I’m just not sure what’s going on right off the bat either haha

I think that these boxes are made out of the wheeledvehicle Blueprint (which incorporates the wheels to the system and that the wheel boxes went wrong (black boxes). btw they are cylindrical. I think that they are supposed to fit on each wheels ( I red that you don’t even need a collision box for your wheels, but I made it anyway) because they use raycast instead of collision.

I suppose the wheel boxes flickers with the ground

I know you said it’s now fixed in your previous question (Previous/related question), but for the sake of anyone else reading this, here’s the simple solution.

The issue apparently stemmed from not applying the scale before exporting from Blender. To apply scale in Blender (or rotation or location for that matter) just hit ctrl+a.

Anywho, glad you got it figured out!


I am sorry to say that I think it fixed it last time for some reason, but after further testing, I found out that Blender has nothing do to if The wheels collision boxes are precisely at the origin of your chassis mesh. But if they just seem Offset, your problem is in your external program (blender in my case). Also, like it’s been discussed, Blender 2.75 has a better exporting and DOES matter. So here’s where we are: just made a brand new project in order to see if that was the issue, but nothing did. The wheels collision are set at the origin point of the mesh they are parented to instead on each on them. let me explain:

We got two odd problems:

  1. The pink collision boxes which are made in the physics asset are too high and should be matching the wheels (no suspension in the wheels settings)
  2. There are four other collision boxes on top of each other that SHOULD be placed by the WheeledVehicle BluePrint according to the wheel’s bone name. What I suspect is the WheeledVehicle BluePrint does not link it like it should, or it does not recognize my bones names (which are generated automaticaly by UE4 using the parent from Blender.) I matched the names with correct capitalization and everything, but I suspect this to be an issue because there is no sign that the blueprint found the correct bone because it has to be manualy typed. I tried without capitalization and (according to a youtube tutorial) should capitalize the names automaticaly if they were found and it did not do it. What suprised me is that the wheels black boxes responded to animations (which mean that the Wheel Class parameter is working) but animation works with the Wheel Class parameter so that may explain it.

Help is appreciated :wink:

I will try to update this issue as soon as I get more information

Alright, sorry it’s been a while, I didn’t have enough experience with vehicles to have a clue what would cause this issue. And speaking of which… now I am making a vehicle of my own, have run into the exact same issue (black wheel collisions in center of screen) and am still clueless as to why this is happening. Did you ever have any luck fixing it?

And lo and behold, I have stumbled upon a solution, albeit maybe not a perfect one. In the vehicle blueprint, within the vehicle movement component, under vehicle setup, setting an additional offset for each wheel does the trick. Hopefully this isn’t too little too late!