Open-world content tools (preview)
Dawn Engine ContentTools is a planned authoring and runtime Gem family (first-release entry Gems/SplineTools, with planned Crowd / VolumetricSky / Destruction related tracks). It fills the “road network → crowds → sky presentation” gap beyond PolyTerrain, Water, and PCG for open-world games and city-scale digital twins.
Maturity: planned / product preview. This page describes target capabilities and rollout stages—not available product APIs. Enabling any future Registry gate must leave existing PolyTerrain, Water, Vegetation, World Streaming, and PCG paths unchanged when ContentTools tracks are off.
It does not replace the general-purpose PCG Gem: splines and crowds may consume PCG / SurfaceData outputs, but must not open a second terrain-write bypass. Where volumetric clouds overlap Weather, Weather’s ownership split (orchestration vs render program) wins.
What problem it solves
After terrain and streaming exist, road dressing, street crowds, and sky presentation still lean heavily on hand work and external DCCs. ContentTools is intended to provide:
- Spline-driven roads, fences, and pipelines with automatic PolyTerrain cut / blend;
- GPU-friendly crowds and light vehicle traffic for street dressing and evacuation drills;
- Volumetric clouds and a day/night time system as a visible early delivery of Weather’s visual layer;
- An optional destruction / fracture track (PhysX Blast-class) for game presentation and damage demos;
- Coordination with World Streaming, double-precision coordinates, and Navigation3D / Recast.
Planned capabilities
Spline tools core (ST0–ST4)
| Milestone | Focus |
|---|---|
| ST0 | Gem scaffold, Registry opt-in (default off), spline asset model, editor probe |
| ST1 | Road profile extrusion, PolyTerrain cut preview, material-layer mapping |
| ST2 | Fence / pipeline / guardrail instancing, junction and branch rules |
| ST3 | Bake into World Streaming cells, ContentHash / incremental rebuild |
| ST4 | Sample city block, performance gates, shipping docs |
Crowd track (CR1–CR3)
| Track | Focus |
|---|---|
| CR1 | Pedestrian agents, avoidance, animation LOD, density-field painting |
| CR2 | Light vehicle traffic bound to spline networks; event triggers (evacuate / gather) |
| CR3 | Optional HTN / Navigation3D decision hooks; multiplayer interest management |
Sky and destruction tracks (after first exit or parallel programs)
| Track | Focus |
|---|---|
| VolumetricSky | Volumetric clouds, time system, and lighting coupling; consume Weather params without duplicating weather authority |
| Destruction | Building fracture via PhysX Blast (or equivalent); game presentation and simulation damage demos |
Full crowd productization, volumetric sky, and destruction need not ship in the same release as SplineTools; the first release targets shippable spline roads / pipelines.
How it will work
Spline assets / density brushes / time system
│
▼
ContentTools
│
├─ SplineTools ──► profile meshes + PolyTerrain cut modifiers
├─ Crowd ──► GPU/threaded agents + animation LOD
├─ VolumetricSky ──► Atom volumetric clouds + SunSky / Weather params
└─ Bake ──► World Streaming cells / Prefab instances
Design rules in the specs:
- One terrain-write entry: PolyTerrain edits go through existing modifier / PCG buses—no bypass writes into section meshes.
- Deterministic bake: seeds and parameters that affect shipped content enter ContentHash.
- Default off: disabled tracks pay no runtime cost.
- Weather owns meteorological truth: VolumetricSky owns visuals; continuous weather parameters stay with Weather when both are in flight.
Explicitly out of scope for v1
| Not in v1 | Notes |
|---|---|
| Full GIS road-network solvers | Authoring splines and rule-based extrusion dominate |
| Certified million-agent city sims | MVP targets look-and-feel and mid-scale drills |
| Replacing EMotionFX / Motion Matching | Crowd animation is instancing + LOD first |
| Certified structural damage analysis | Destruction is presentation / demo grade |
| Standalone general PCG graph framework | See the PCG preview |
Related systems
| Topic | Relationship |
|---|---|
| PolyTerrain | Host for road cuts and surface blending |
| PCG (preview) | Weights / scattering can connect to spline-sampling nodes |
| Water | Waterfront curb lines and shore-distance queries |
| World Streaming | Baked networks and crowd density stream with cells |
| Weather (planned) | Parameter authority for sky and precipitation |
| Navigation3D / Recast | Pathfinding substrate for pedestrians and flying agents |
| HTN Planner | Optional driver for crowd events and tasking |
Status and next steps
This chapter is a product preview. When SplineTools ships its first release, expect Quick start (draw splines, generate roads, bake to cells), editor panels, and performance guidance; Crowd / VolumetricSky / Destruction will expand as separate subsections per track.