Guide to Changing Water Physics and Floating Mod Basics v1.0 for Spintires: MudRunner (v18.10.18)

The instructions are provided as an XML file and in the video. The archive also contains an already modified media file. Do not place the file in the root folder, but in the mods folder (the yellow Media folder).

The main principles of a floating mod. The lighter the body (PhysicsModel), the easier it is for the mod to stay afloat. And the larger the volume and the lighter the wheels, the better they will keep the mod above water. This is the basic principle. Almost the same as in real life.

Here are the nuances. The wheels should not be lighter than 50 (less wobbling), but preferably not heavier than 100. The larger the volume, the better, regardless of how it is achieved. You can make the size 1.0 radius and 1.0 width. Or you can make it 0.4 radius and 5.0 width, for example, if these wheels are under the bottom of some barge. Or 2.0 radius and 0.7 width. In short, the total volume is important. And the more of these wheels the mod has, the better it stays on the water.
The body of jeeps and buggies should be light, 600-1000 game kg, if they have 4 wheels, for example, sized 0.8 by 0.8. With the default media, such a mod will already float on water. But to make it actually move (drive on water), you need to increase the wheel friction. If offroad wheels by default have friction BodyFriction="1.0" SubstanceFriction="1.2", then to make the mod float, you need to increase it to at least BodyFriction="9.0" SubstanceFriction="9.2". Better to set it to 20.0. But with such friction values on the wheels, the mod will jerk a lot on mud. Also, a mod that is too light bounces unnaturally and unrealistically. It’s immediately obvious that it is very light. That’s why you need to modify the media file. With the modified file, the weight of jeeps can remain default, which is usually 1600-2500 game kilograms. And the wheel friction can remain default. Then the mod bounces normally and doesn’t jerk on different surfaces. If everything is done as in the video, the physics, in my opinion, do not suffer.

Then add invisible wheels everywhere you can hide them. Then the mod can weigh 6000 or 15000. And at the same time, it can carry default loaded cars on board, if this mod is a ship or some kind of barge.