can't get vehicle armature to work

I’ve had this problem for ages!!!

I have currently set up a simple rig of a vehicle in blender:

although even after setting it up correctly, the wheels of my vehicle scramble all over the place in the simulation:

sometimes they scramble in the middle…

So I have oriented the bones so the bones are facing the y axis as shown(which is left) and my vehicle is facing forward(x)

I have tried placing the root bone in the centre but problem happens

I would love if someone would be able to check out my model and tell me what is going on

aprat from the skinning issues, make sure the “head” of the bone is center to the wheel , also the head of the root bone 0,0,0
wheels on the ground eg the bottom of the wheel is z=0
in the phat editor make the wheel bodies sphere and set to kinematic

if this fails then pm me a link to the file and i’ll have a look

I have done everything I can think of Geodav. Please help me here is the link:

the file with just centre without the y has the bone set to the grid centre, the other has the bone set to the orange dot(origin of the armature).

I’ve attempted to fix it with another 3 hours, I have set the whole vehicle to have z=0. I have moved the individual bones to as close to the centre of the wheels as I can get, I have tried setting the root bone to the origin of the grid, and the origin of the actual armature(orange dot) I have set all of the wheels to be spheres collision regions and have set all of them to kinematic. The only difference between the example project car and my vehicle are the vertex have no weight errors.

I am doing this for a school major project (a high school thing in Australia) and I need this to work because the ATAR submission(in australia that is the final exam) is coming up in 3 days. I will really appreciate all of the help you can do.

Thanks Geodav

sent you a pm

ok please don’t take offence at this but it’s a mess,

  1. go back to the model before you added the rig and sort out the alignment of all the parts
  2. align the mesh x=forward z=up , align the mesh ‘origin’ this way and put it in the center of the mesh
  3. set the mesh so that the bottom of the wheels are touching the ground.
  4. create an armature of 1 bone, switch on axis/xray and align the bone axis x=forward z=up, location 0,0,0
  5. duplicate the bone and place them in the center of the wheels
  6. parent the wheel bones to the root bone (keep offset)
  7. parent the mesh to the armature
  8. set the vertex groups/weights
  9. export via fbx

notes, didn’t notice any uvw mapping or smooth groups !!!

“align the mesh origin this way” what does this mean? How do I align an origin. Also the bones have a different origin to the mesh what origin do I align the root bone to?
when you say place the bone at 0,0,0, are you referring to the exact center of the grid?

ue4 makes a default uv mapping so no I didn;t add one.

Does this mean that the actual alignment of the mesh contribute to the failure? What if the wheels were bent for artistic looks?!

ok for easy use and so you don’t get confused in the engine i say align the mesh so that the front is pointing along the X axis
yes 0,0,0 is the exact center of the grid, use the co-ordinate system to set it, even if your just a little off it will cause problems in the physics editor
uvw mapping well thats up to you
well if the wheels are supposed to be like that then fine

then main thing is the placement/alignment of the root bone and then the alignment of the wheel bones otherwise you just get issues

Thanks for your help Geodav. I ended up exporting the sedan from the example project and using that skeletal mesh. I noticed that the skeletal mesh in the example project had bones much larger, and not only were the bones at 0,0,0 but the orange origin was also at that point. I’m guessing my issue was to do with either of those 2 playing up. Thanks again its working now!