Mud deforms wheel mesh

I'm running an older version of the exe for various reasons (may or may not be relevant), but I've noticed that if my wheels are clean (like when you spawn a truck on a clean, mud-free hard surface) both the tire model and the wheel model are fine with nice smooth crisp edges where applicable. However the moment you touch mud, both the tire model and the wheel model start to deform, and I'm not referring to the "bulge" at the bottom of the tire from setting the softness in the XML. Can anyone confirm whether this is just a thing that we have to put up with now, or am I going to have to figure out what I'm doing that's causing it? Screenshots to follow...

    Note the smooth seam between the wheel & tire, as well as the smoothness of the holes through the face of the rim.

    Notice the distortion around the edge of the wheel, as well as the warping of the holes.

The tire mesh deformation is understandable, since I assume that was done to give the illusion of mud building up in the tread lugs and such (nothing like those horrid blobs of mud that stick to the tires with the default/vanilla settings, that just looks ridiculous and unrealistic, IMO) but why for it warp my rim too?

@mexican_420, That's in the game and was one of my biggest problems with this game. I'd make nice looking wheel or other parts and when put in game, it does that. Absolutely hate it but it's nothing on your end. It's done by the game itself.

The fix is kinda easy buuuut
You gotta make a high poly to low poly normal bake, or not split the edges of the tires (bevel/smooth them)
I have the same issue too and it's related the vertex deformation of the meshes and the edges just get pulled in different directions from each others

@forces, Oh really? A normal map stops that? I didn't know that because I had the same problem when I was making wheels back in the other forums. That's odd tho Forces because I don't see that happening on the rest of the mod, only on wheels.

I had a auto correct there, and not split the edges of your model

And yeah meshes that aren't solid will have the issue
It only happens in the wheels because they are in constant deformation by the game engine (you don't skin wheels to for the game does it for you and that leads to miscalculations when resetting the area that isn't in contact with the ground, the softer the tire the worst
From what I've seen in the stock models almost all tires on the game are smoothed low poly toroids/rings that have a rough shape of the high poly version of the final tire
Only Bregel takes the time to recreate that result with his tires (lc75,fj40 soa, fj80 and Land crusher) are the mods that have said way of making tires (and not all sets from what I see on the editor of you take out of the code the normal maps)

I find that the best way to avoid it, is by giving a smooth shading to the side of the lugs and a flat shade to the contact area, the idea came from a similar issue with BeamNG wheels hi deformation calculation Wich is more precise because how simple it is, they only apply the deformation in the y axis in relation to the normal of the flat face in relation with the ground and only to the sides (z axis) when moving ,while spintires bends the vertex's of the tire in relation to the normal of the XML generated cylinder (Wich has only 16faces) and extrudes the mesh in all Axis (x,z) while compressing it in y so it's far more complicated and thus prone to that awful miscalculation

So if I make my wheels & tires all one mesh (while observing the 18k poly limit? Impossibru!), instead of a mesh for the tire and another mesh for the rim, the wheels (rims) shouldn't deform?
Or if the wheel/tire is shaped like a hockey puck (flat sides intersecting the round edge at 90°) instead of like a donut (bulged/rounded sidewalls and/or tread surface)?

last edited by Mexican_420

no no no, rim and rubber can be separate its rubber and thread pattern wich must be one, and also low poly (the extra detail will be added with the normal maps)

i've done it just 1 time, in my willis MB trailer wheel

edit, hey also the RubberRadius code you gotta leave a offset from the rim mesh to get the best result in the deformation of the tire, if not the rim will also be deformated with the rubber of the tire

last edited by Forces

@Mexican_420 this can fix your issue 100% as long you dont edge split the thread of the tire
Youtube Video