jpmschweitzerandClaude Opus 4.6
8217ebc0fb
Update Camera3D to exact D-019 angle (-72.5° from horizontal). Replace single DirectionalLight with three-point studio rig (key 1.0, fill 0.4, rim 0.3) for clean silhouettes without baked shadows. Add generic NPC capsule model (24×32px footprint per D-044). Document full pipeline spec in renderer/README.md. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
112 lines
5.3 KiB
Markdown
112 lines
5.3 KiB
Markdown
# Settled Reach — Sprite Render Pipeline
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Offline Godot 4 renderer for the 3D-to-2D sprite pipeline. Produces entity and structural sprites at three resolutions from a fixed camera angle, with outlines applied at working resolution.
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## Camera Specification (D-019)
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- **Angle**: -72.5° from horizontal (= 17.5° from vertical, the midpoint of the 15-20° from vertical range)
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- **Projection**: Orthographic (`size = 1.4`)
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- **Position**: `(0, 3, 1)` — above and slightly in front of the model origin
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- **Godot Transform3D**: `Transform3D(1, 0, 0, 0, 0.30071, 0.95372, 0, -0.95372, 0.30071, 0, 3, 1)`
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This is "the angle" per D-019 amendment (2026-02-12). All entity, object, and wall sprites for v0.1 are rendered at this angle. The Godot gameplay camera is purely orthographic — this tilt is an art convention expressed through the 3D render.
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## Lighting Rig
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Three-point studio rig. All lights have `shadow_enabled = false` — sprites are shape templates, no baked shadows or directional lighting. The Godot runtime PointLight2D pipeline provides all scene lighting at runtime (D-043).
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| Light | Energy | Direction | Purpose |
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|-------|--------|-----------|---------|
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| KeyLight | 1.0 | Matches camera angle (-72.5° from horizontal) | Main illumination; ensures front face is lit as the camera sees it |
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| FillLight | 0.4 | 45° from right side (-45° pitch, +90° yaw) | Fills shadow opposite the key; no deep-black patches on right face |
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| RimLight | 0.3 | 45° from behind (-45° pitch, +180° yaw) | Back-edge accent; defines silhouette boundary for outline processing |
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**Rationale**: Even 3-light coverage ensures no black patches on a convex mesh, keeping surface colors flat and readable for the outline processing step.
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## Resolution Chain (D-043, D-044)
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```
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1024×1024 — source PNG, full fidelity for outline processing
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↓ bilinear resize
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256×256 — working PNG, outline applied at 4-8px, color #333340
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↓ bilinear resize
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64×64 — runtime PNG, deployed to client/assets/sprites/
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```
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Outline implementation: alpha-mask dilation + flat color fill. Outline width in `render_export.gd`: `outline_width_px = 4` (at 256px = 1px effective at 64px).
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## Entity Footprint Spec (D-044, D-066)
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- Entity sprites occupy a **24×32px footprint** within the 64×64 visual tile
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- Entities render across a **2×2 sim tile sprite footprint** (D-066)
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- Visual tile = 64×64px at runtime; sim tile = 32×32px (0.5m)
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- **NPC model scale**: `CapsuleMesh(radius=0.25, height=0.62)` at camera size 1.4 produces ~24×32px apparent size in the 64px output tile
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## Usage
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### Command Line
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```bash
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# From the renderer/ directory
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godot --path . --headless --quit-after 1200 res://render_scene.tscn -- <model_name>
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```
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Or use the `/sprite-gen` skill which wraps this command and handles output placement.
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### Adding a New Model
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1. Create `renderer/models/<model_name>.tscn` — root node is a `MeshInstance3D` (or `Node3D` with children)
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2. Center the mesh at the origin
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3. Use a flat `StandardMaterial3D` (no baked shadows — just albedo color + roughness)
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4. Run: `/sprite-gen <model_name>`
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5. Output: 12 PNGs in `renderer/output/` (4 directions × 3 resolutions)
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6. Runtime sprites: copy 64px variants to `client/assets/sprites/`
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### Material Guidelines
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- **Entity sprites**: neutral flat material (albedo Color(0.5, 0.5, 0.5)). D-033 relationship color tinting applied at runtime.
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- **Structural sprites**: use zone-appropriate texture (`textures/wall_institutional_era1.png`, etc.)
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- No specularity: `metallic = 0.0`, `roughness = 0.9`
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- No emission, no normal maps — shape is the signal
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## Models
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| Model | File | Type | Notes |
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|-------|------|------|-------|
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| `wall_structural` | `models/wall_structural.tscn` | Structure | 1.0×0.8×0.2 box, institutional era-1 texture |
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| `wall_bar_green` | `models/wall_bar_green.tscn` | Structure | 1.0×0.8×0.2 box, green panel texture |
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| `npc_generic` | `models/npc_generic.tscn` | Entity | Capsule silhouette, neutral grey, 24×32px footprint |
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## Output Naming Convention
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```
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<model_name>_<direction>_<resolution>.png
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wall_structural_north_64.png
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npc_generic_south_256.png
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```
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Directions: `north`, `east`, `south`, `west` (model rotated 0°, 90°, 180°, 270° around Y axis).
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## Runtime Sprite Path
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64px sprites are deployed to: `client/assets/sprites/`
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Naming convention at the client side is `<model_name>_<direction>.png` (64px only — the 1024 and 256 variants stay in `renderer/output/` as pipeline intermediates).
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## Design Constraints
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- **No baked lighting**: sprites are shape templates. Lighting is applied at runtime by Godot's PointLight2D per D-046.
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- **No baked shadows**: shadow direction would conflict with runtime point lights at arbitrary positions.
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- **No baked mood**: flat materials, three-point neutral rig. Zone atmosphere comes from runtime CanvasModulate.
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- **Outline applied at 256px, not 64px**: ensures outline is crisp after bilinear downscale.
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- **Transparent background**: `SubViewport.transparent_bg = true` — sprites are PNG with alpha, composited at runtime.
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## Cross-References
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- D-019: Camera angle spec and amendment
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- D-043: Art direction — "functional warmth," resolution chain, outline color
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- D-044: Visual hierarchy, entity footprint spec
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- D-049: Z-level rendering stack (sprites land on layers 2-3)
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- D-066: Dual-scale grid, 2×2 sim tile entity footprint
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