# Scene Composition

## Definition

A Scene is a situated composition through which a Realm becomes present, experiential and interactive. It spatially organizes Components. An Area is different: it logically organizes Components and Scenes without changing their spatial position.

## Ten-step assembly

1. **Purpose first.** Name Realm, Scene Purpose, intended Activities, participants and authorized intelligence.
2. **Light before objects.** Choose sky, horizon, time, weather and principal environmental light.
3. **Frame the world.** Establish dark peripheral framing, one inhabited center and at least two continuations beyond the viewport.
4. **Set ground and elevation.** Build traversal, boundaries, platforms, stairs, water and transition zones.
5. **Place organizing forms.** Use one dominant gathering, creation, navigation, governance, exchange or custody form.
6. **Situate Components.** Snap anchors; respect scale; compute depth; connect materials, shadows and light.
7. **Make presence legible.** Choose contextual Avatar, Ki, Ally and Actor embodiments.
8. **Apply atmosphere.** Composite ambient, key, local, rim, reflection, shadow and depth haze.
9. **Add state and motion.** Let the world respond before introducing Overlays.
10. **Validate in context.** Test two lighting conditions, occlusion, focus, accessibility, state transitions and alpha.

## Composition constraints

- Begin near a 70/20/10 ratio: environmental continuity / meaningful interactive structure / explicit informational treatment.
- One organizing form leads. Up to three secondary light pools can support it.
- Maintain a dark-to-light value path from periphery to inhabited center.
- Do not fill every gap. Negative space is the Field through which relationships become visible.
- Keep at least 15% of the frame available for contextual Overlays without covering the organizing form.
- Avoid symmetrical perfection. Architecture can be ordered; nature, wear, light and participation should keep the Scene living.

## Runtime recomposition

When a Component moves or changes, recompute:

1. projected position and depth key;
2. collision and traversal;
3. occlusion volumes and foreground response;
4. contact and cast-shadow receivers;
5. local-light influence and material reflection tint;
6. overlap density and silhouette separation;
7. Attention prominence and focus path;
8. accessible focus order and alternative spatial description.

## Background-to-ground bridge

Every Background declares a horizon, principal light vector, haze profile, transition band and color-reflection profile. Foreground Terrain overlaps that transition band with at least two of: shared architecture, vegetation, path, shadow, water, atmospheric veil or elevation continuation.

## Reference Scenes

The package includes nine visual and structured Scenes: Commons — Alcove, Hearth, Council Table and Courtyard; Observatory; Grove; Apiary; Council Fires on the Prairie; and The Keep. The first four are untouched supplied primary references. The last five test extensibility.