Rolling Hills Physics Addon - Realistic Vehicle Physics, Hills and Jumps for Project Zomboid B42 (Project Viewpoint)

Rolling Hills Physics Addon introduces additional vehicle physics for Project Zomboid, making driving across hills and uneven terrain more realistic.

Designed as an optional extension for Rolling Hills and Project Viewpoint, the modification changes how cars react to slopes, gravity and different surfaces.

Vehicles can accelerate downhill, struggle on steep climbs, lose momentum on grass and even briefly leave the ground when crossing hill crests at high speed.

Requires Project Zomboid Build 42.21.

Realistic Vehicle Physics

The addon introduces several new driving mechanics.

• Downhill Gravity - Vehicles naturally gain momentum while traveling downhill.
• Uphill Resistance - Climbing becomes increasingly difficult on steeper slopes.
• Vehicle Weight and Engine Power - Heavier vehicles and weaker engines behave differently when climbing.
• Grass Drag - Cars lose speed more quickly when coasting across grassy terrain.
• Reduced Cliff Traction - Extremely steep surfaces progressively limit wheel traction.
• High-Speed Jumps - Vehicles can become airborne when crossing suitable hill crests.
• Experimental Cliff Falls - Single-player vehicles can fall using native Bullet physics and collision damage.

The goal is to make terrain an important part of vehicle handling without replacing Project Zomboid's existing driving system.

Uphill and Downhill Driving

Driving uphill requires more engine power as the slope becomes steeper.

Vehicle mass also affects climbing performance, making terrain more challenging for certain cars.

Downhill movement benefits from gravity, while braking remains available through the normal vehicle controls.

On grass, additional resistance causes vehicles to slow down sooner.

Vehicle Jumps and Cliff Falls

Optional jump mechanics allow cars traveling at sufficient speed to leave the ground when crossing a hill crest.

Ordinary low-speed driving remains grounded.

The addon also includes experimental cliff falling with native crash damage, but this feature is restricted to single-player.

Sandbox Configuration

Vehicle physics can be customized through world or server settings.

Balanced is the default configuration, with lower physics strength available for players who prefer gentler handling.

Settings are located under:

Sandbox > Rolling Hills Physics

These options are not controlled by the Project Viewpoint shader menu.

Required Mods and Installation

The following components are necessary:

1. ZombieBuddy
2. Project Viewpoint
3. Rolling Hills 0.2.19 or newer
4. Rolling Hills Physics Addon

Installation Steps

1. Install ZombieBuddy according to its own instructions. Simply enabling its mod is not enough.
2. Enable all required modifications and Rolling Hills Physics.
3. For existing saves, use More > Choose Mods.
4. Fully restart the game and approve the Java addons, including updated versions.
5. Enter the game world and press O to activate Viewpoint.
6. Allow terrain generation to finish before driving.

Rolling Hills remains functional without this physics extension.

Multiplayer Support

The addon includes multiplayer functionality, but several limitations remain.

Both the server and connected players must install the required components.

Every player must also install ZombieBuddy locally and approve the client-side Java addons.

The server controls physics settings and Rolling Hills terrain parameters.

For consistent multiplayer behavior, use Rolling Hills terrain. Physics forces are suspended when a client uses independently configured Viewpoint terrain.

Important: Integration with Viewpoint 0.1.6 has not yet been tested in a live multiplayer session.

Water Compatibility and Limitations

Optional integration with Water for Project Viewpoint allows water-related movement systems to take priority over slope and cliff forces.

However, complete compatibility with Viewpoint 0.1.6 remains unverified.

Additional limitations include:

• Cliff falling works only in single-player.
• The addon does not replace the complete world collision mesh.
• Overhangs and falling mechanics for walking characters are not added.
• Streaming collision areas may briefly interrupt airborne vehicle movement.
• Vehicle god mode prevents normal component damage.
• Towing, all vehicle packs and extended multiplayer sessions remain insufficiently tested.

PoolPit 2.1.0 requires an update for Viewpoint's newer shaders. Rolling Hills 0.2.21 fixes an older wetness-data issue affecting vehicle transforms, but does not resolve black water in the default renderer.

Compatibility Overview

Rolling Hills Physics Addon makes driving more engaging by introducing meaningful terrain resistance, momentum and gravity. It is particularly suitable for players who already use Project Viewpoint and Rolling Hills and want vehicles to react more naturally to the landscape.