Navigation & Collision

SplashEdit uses DotRecast (a C# port of Recast Navigation) to generate navigation meshes for your scene. The nav mesh tells the PS1 runtime where the player can walk.

How Navigation Works

1. SplashEdit collects geometry from all PSXObjectExporter components
2. It voxelizes the scene into a 3D grid at the configured cell size
3. Walkable surfaces are identified based on slope angle and step height
4. Convex navigation regions are generated (polygons with up to 6 vertices each)
5. Portals (connections between adjacent regions) are computed with height deltas
6. The result is exported as binary data in the splashpack

Navigation Settings

All navigation settings live on the PSXPlayer component:

Setting	Default	Description
Nav Cell Size	0.05	XZ voxel resolution. Smaller = more accurate edges, slower export, more memory.
Nav Cell Height	0.025	Y voxel resolution.
Max Step Height	0.35	Maximum height difference the player can step over.
Walkable Slope Angle	45	Maximum slope the player can walk on, in degrees.

Nav Cell Height is broken

The Nav Cell Height setting does not work correctly in the current version. Leave it at the default.

Step height must match your geometry

If your stairs are 0.5 units tall but Max Step Height is 0.35, the player won't be able to climb them. The voxelization is correct but walkableClimb prevents connections between height levels.

Collision Types

Set on each PSXObjectExporter:

Type	Description
None	No collision detection. Walkability comes from the nav mesh.
Static	Solid wall. Player is blocked. Use for walls, pillars, fixed obstacles.
Dynamic	Moveable collider. For objects repositioned via Lua at runtime.

Dynamic collision AABB limitation

Rotating objects via Lua does not update their AABB collision bounds. The collision box stays in the original orientation. Only position changes work correctly for dynamic colliders.

How Collision Works at Runtime

The PS1 runtime uses AABB (axis-aligned bounding box) collision:

• Static colliders block player movement
• Dynamic colliders are checked against the player each frame
• Trigger boxes fire Lua events on enter/exit (see Trigger Boxes)
• Line-of-sight checks are used by Interactables when requireLineOfSight is enabled

Tips

Cell size trade-off

Smaller cell sizes produce more accurate navigation edges but generate more regions and use more memory. For most scenes, the defaults work well.