Epiphany Aquarium Engine

C# engine-core seed for the next Epiphany Aquarium line.

This repo starts after the web and Rust prototypes taught the expensive lesson: the Aquarium wants an owned renderer, owned state model, and owned interaction grammar. Stride can donate useful structure and tooling, but the engine shape is Aquarium-first rather than framework-first.

Intent

• C# host with renderer architecture kept legible in Rider.
• Grid-centered camera and world-space interaction invariants as first-class engine contracts.
• Diegetic UI surfaces driven by Aquarium objects instead of admin chrome.
• CultNet for Epiphany communication.
• CultCache for settings, persistent client state, and reload recovery.
• Procedural audio and visual state treated as coupled signals.

Borrowed Lessons

• The web client proved the interaction grammar: objects first, panels only as local unfold surfaces.
• The Bevy prototype proved the renderer direction: raymarched bodies, Grid-space fields, HDR, bloom, and camera/Grid invariants.
• The Rust synth work proved the audio module deserves its own small, sharp API.

First Build Target

Create the smallest C# executable that opens a window, owns the camera/Grid invariant, and renders one sun plus orbiting planets with diegetic labels. Everything else earns its way back in.

Run

dotnet build Aquarium.Engine.slnx
dotnet run --project src\Aquarium.Engine\Aquarium.Engine.csproj

Headless smoke:

dotnet run --project src\Aquarium.Engine\Aquarium.Engine.csproj -- --headless

The first cut uses Stride as a NuGet-hosted shell through Stride.CommunityToolkit.Windows. Stride is scaffolding; the Aquarium owns the camera/Grid invariant and the renderer direction. See docs/stride-boundary.md.