I built the Path Tool on the same HDA core as the River Tool, but tailored for trails, roads, and walkable paths.

It lets artists lay down natural-looking paths that respect terrain height, branching logic, and environmental blending, all directly in Unreal.

Note: This project was developed for an un-announced product. The assets, images, and implementation details shown here are test files and development materials used during tool creation, not the final production version with real art assets.

Key Challenges

• Walkability → Paths had to remain playable by ensuring smooth slopes and natural blending with terrain.
• Iteration Speed → Needed to provide fast, localized edits over large landscapes.
• Avoiding Intersections → Trails that overlapped or branched had to resolve naturally, without harsh artifacts.
• Visual Variety → Paths needed decals, textures, and details like cart tracks and footprints for storytelling.
• Flexibility → Unlike rivers, paths can ascend slopes and branch freely without waterfall stepping.

Main Features

Artist-Controlled Splines

Artists drew intuitive path splines that auto-adjusted the heightfield for smooth traversal, keeping gameplay slopes within spec. The tool preserved surrounding heightfield detail, so nearby terrain blends stayed intact after every recompute.

Path Meshes & Decals

Generated path meshes with custom decals (cart tracks, footprints, material variation) driven by vertex colors that feed Unreal material layers. This kept transitions soft and prevented harsh edges or awkward intersections where trails meet terrain.

Solver-Based Intersection Handling

A custom Houdini solver simulation removed overlaps at sharp angles, ensuring paths branched or crossed cleanly even when artists dragged splines through tight turns.

Terrain Integration

Auto-leveled terrain along each path to guarantee walkable routes, then blended the new surface back into the landscape without hard cuts. The tool generated a custom skirt mesh around path edges so artists could feather between authored geometry and native terrain based on gameplay needs.

Intersection Snapping

When curve ends are nearby, paths align automatically in their shared travel direction. Artists keep spline inputs simple; the tool resolves branching order and spacing in Houdini before sending meshes to Unreal.

Shared Core with River Tool

Reused caching, tiled processing, and optimized cook times with the Terrain River Tool, keeping both HDAs performant during large world edits. Both tools also integrated with the Terrain Scatter System for environmental dressing.

Results

Artists could author walkable, believable trails that blended naturally into terrain without manual cleanup. The skirt meshes handled the transitions automatically. Decals, branching, and directionality added visual richness while keeping cook times manageable. The tool supported multi-artist workflows across large landscapes.