OK, my bp IS now a **vehicle **anim instance. It wasn’t before and that was causing an issue… I just listed the problems I had so if someone else has them that’s stuff that’s easy to miss.
(I couldn’t create a wheel handler node)
Also in my picture there are a lot of bones there that can’t be seen. They are stacked…
ie: the viswheel, physwheel, hub, pos hub, kingpin… They are all in the exact same spot. Most of them aren’t weighted to the mesh, they are all just referenced for locations in the Anim_BP.
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So the buggy wheels are just part of the buggy mesh. They aren’t physically attached to the rollcage mesh, they need to turn separately. But they are all ‘one mesh’.
If you just select all the wheel polys and delete them the rig should work fine still. You just won’t have visible wheels in game.
This is how I’m working. My mesh in the above picture is just the chassis (frame, suspension, hubs). But the entire skeleton is in the file.
I did that for two reasons.
1- it’s easier to skin and rig without having the wheels in the way.
2- I also wanted interchangeable wheels.
So you can make a copy of the buggy file. In one file select all the wheel polys and delete them. Export that and you should have a working buggy without visual wheels.
In the other file delete all polys EXCEPT the wheels and export that. You should now have 4 wheels that work. I like to driv them around.
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Import the rollcage mesh. Let the import make skeleton but NOT a physics mesh.
Now in the vehicle BP scene window you can use the chassis (rollcage) as the base mesh. -
Import the wheels mesh using the skeleton from the rollcage. DO make a physics mesh on import.
Add a skeletal mesh component to the vehicle_bp and use the wheels mesh. They should all line up and work together in game. (the body and wheels)
Make sure both the chassis and wheels use the anim_bp. (this tells the suspension on the rollcage how to move, and the wheels how to move).
(they move by how the anim bp tells them to — using the wheel handler node)
—vis wheel/ phys wheel.–
So these are just bone names.
The actual visual wheel can be named whatever you want (tire, rim,wheel). But they HAVE to be rigged to the VisWheel bones.
The physwheel is just a bone that the anim_bp uses for attaching a phys collision. Nothing in the 3d file is attached.
:: OK, so now you have imported :
1- a skeletal mesh that is the skeleton rigged with the rollcage/body of the car. (no phys)
2- a skeletal mesh that is only the wheels and skeleton. But on import you used the rollcage/body’s skeleton. You make a phys mesh on import with this. In this phys mesh delete all the collision shapes.
Chose the ‘PhysWheel’ bones one at a time and add/replace bodies (this is important - the add shape button is wrong for this) the collisions with SPHERE already chosen in the phys body tab (mine is on right side of screen, sorry away from my comp atm)
Doing this on the wheel mesh makes the phys models the same size as your visual wheel mesh.
Now change the ‘sphere’ n the right hand tab to ‘box’. Go back to the bones tab (left side - we are still in the physics file)
select the very root bone (is called vehicle), add/replace bodies button again.
You will get a tiny little box in the middle of the wheels, scale this up the the vehicle body size. After the wheels are done you can go to scene preview tab and chnage the wheels mesh to the body mesh. then make a good collision shape for body (Or import a custom one)
This is getting long…
So that is all the ‘physwheel’ bones are for. attaching the collision sphere inside Unreal.
The VisWheel bone is for rigging the actual tire to in 3d program.
The wheel you see is just a skeletal mesh.
So now you’ll have a working chassis and you can make as many wheel files as you want and swap them out in Unreal. Either by making several BP’s, or swapping mesh components…
Hopefully that’s not too confusing.
If the wheels are sinking into the ground check:
1- if you recaled a rig this can happen. Hence the reason I finally broke down and just made a new rig from scratch. But if you zeroed out the bones you might be OK. This can be one of those 3d program> game engine nightmares. Depending on programs used.
2- you haven’t adjusted the wheel size in the wheel BP’s to the proper radius.
in game use the console (`) and type pxvis collision
This will show pink spheres for collisions and black 'wheels. The black wheels are what the car actually drives on. Their position is attached the the visWheel bone. This can be changed with their radius and width in the wheel BP file.
If the radius is too small then the visual wheel in game will sink into the ground. it is riding on these invisible wheels, not the wheels you actually see.
Also make sure the wheels skeletal mesh (that you attach to the BP) has collision set to NONE.
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On my vehicles I have 3 main parts:
The chassis (chassis skeleton) (this is frame, suspension, hubs)
The Wheels (Chassis skeleton, wheels phys file) (wheels only)
And then I have a body mesh that has a different skeleton (for doors, steering whel animations). I just plop that on top of the BP file too. SO I can change out the wheels and/or body.
(then on this skeleton I also have separate doors that I can swap out, different lights, tops, hoods).
You can also rig the tires as one file, and the rims as another. So you can easily swap the tire but not the rim, or vice-versa