Trailbound – Off-Road Driving & Deformable Mud

Build muddy off-road adventures with physical wheels, deformable mesh soil and a stylized forest. Includes a driveable 4x4, 87 nature variations, clear editor tools and full editable source.

COMPATIBILITY AND SETUP

• Unity 6.0 LTS baseline: 6000.0.60f1 (lowest tested patch). Verified Windows x64 editor/player workflow.
• URP 17.0.4 materials and demos in the main package; native HDRP 17.0.4 Shader Graph, materials and all four demos in the included optional Compatibility/Trailbound_HDRP_1.0.0.unitypackage.
• Requires Core RP 17.0.4, Input System 1.14.2, your chosen URP or HDRP package and Unity Particle System. Installing both pipelines is not required. Enable Input System or Both for demo controls.
• Built-in RP, mobile, WebGL, VR and consoles are not validated targets. Blender is optional for editing art sources.

INCLUDED CONTENT

• 88 prefabs: 1 exterior expedition vehicle, 15 trees (pine/spruce/oak, five forms each), and 72 environment forms (24 families, three forms each).
• 10 flower species plus grasses, ferns, shrubs, fallen wood, stones, mushrooms and forest litter.
• 4 demo scenes: ForestRun, DeveloperLab, TreeGallery and EnvironmentGallery. Three vehicle presets and five surface presets.
• Full editable C#, shaders and documentation. Six native Blender source documents and portable generation/export scripts in Source/Trailbound_Blender_Source.zip.

GEOMETRY AND TEXTURES

• Vehicle: 44,272 rendered triangles, counting all four visible wheels. Separate chassis/wheel physics meshes. Exterior only; no vehicle LOD chain or detailed interior.
• Trees: LOD0 7,564–49,792 triangles; LOD1 2,872–18,917; LOD2 721–4,869.
• Environment: LOD0 48–12,370 triangles; LOD1 23–5,936; LOD2 9–2,474. All 87 nature prefabs have three LOD levels.
• 51 PNG art textures: 3 vehicle maps: base/normal at 4096×4096 and metallic/roughness mask at 2048×2048, 30 bark maps at 2048×2048 and 18 wood maps at 1024×1024. Base colour, tangent normal, and vehicle metallic/roughness mask. Most foliage/ground cover uses vertex colour.
• 42 main art materials, instanced/cell-culled grass and shared vegetation wind. The HDRP patch also includes native demo label materials and volume settings.

PHYSICS AND AUTHORING

• 5 rigidbodies per vehicle: chassis plus four physical wheels with ConfigurableJoint suspension. Authored convex contact shapes; no WheelCollider dependency.
• Mesh-patch soil with hardness in vertex alpha, wetness/compression in UV2, live ruts, rut-edge soil displacement and collider updates. Trees use UV3 wind weights.
• Vehicle / Surface Workshop, grouped Inspectors, scene painting, units, tooltips and Undo-aware mesh/profile changes. Runtime API can accept your game input.
• Game-oriented traction and estimated physical parameters. Full gearbox/RPM/differential simulation, winching, water physics, networking, Unity Terrain conversion and saved rut persistence are not included.

DOCUMENTATION

Offline HTML and editable Markdown are also included.

CHANGELOG

MAKE THE GROUND PART OF YOUR DRIVING GAME.

Trailbound brings together a driveable expedition 4x4, deformable mesh soil and a complete stylized forest for off-road adventures, exploration and driving prototypes.

Build trails where wheel load and slip leave real ruts, soft ground slows the vehicle, and deeper wheel burial produces more rearward mud spray.

DOCUMENTATION

Installation, editor guides, vehicle and soil tuning, code examples and the runtime API.

PHYSICAL WHEELS & DEFORMABLE SOIL

• Independent physical wheels: rigidbody wheels with authored contact meshes and adjustable suspension, damping, traction, brakes, mass and anti-roll response.
• Ground that responds: local mesh compression, updated collision, displaced soil at rut edges, variable bearing strength and slip-sensitive resistance.
• Visible mud response: persistent tracks during play and rearward wheel spray that increases with wheel burial and slip.

BUILD & TUNE IN THE EDITOR

Use the Vehicle / Surface Workshop, grouped Inspectors, clear units and tooltips. Start with three vehicle presets and five surface presets, then paint hardness, visual wetness and colour directly in Scene view.

A FOREST WITH VARIETY

15 tree forms across pine, spruce and oak, plus 72 environment forms across 24 families. Includes 10 flower species, grasses, ferns, shrubs, fallen wood, stones and forest-floor detail.

Shared vegetation wind adds rooted tree bending, leaf flutter and gusts. All nature prefabs have three LOD levels; meadow grass uses instancing and distance culling.

FOUR DEMOS TO EXPLORE

Drive the winding ForestRun trail, compare five surfaces in DeveloperLab, and browse the labelled TreeGallery and EnvironmentGallery. The driving demo includes mouse orbit and camera zoom.

FULL EDITABLE SOURCE

All Trailbound C# code, shaders, documentation and original art sources are editable. Six native Blender source files and portable generation/export scripts are included.

Vehicle wear, bark and wood grain are surface detail. The tyre tread is continuous geometry.

UNITY 6.0 LTS — URP & HDRP

Start with the supplied URP demos, or import the included native HDRP material and demo package. Both variants share the same editable driving and soil systems. Tested with Unity 6000.0.60f1 and URP / HDRP 17.0.4.

URP / HDRP SETUP

VERSION 1.0 SCOPE

Includes one exterior vehicle, mesh-patch soil and a game-oriented traction model. Unity Terrain conversion, full gearbox / RPM / differential simulation, winching, water physics, multiplayer and saved rut persistence are future work.

ROADMAP

CHANGELOG