VIVIA — Rendering Pipeline

GPU Pipeline (wgpu)

The renderer uses wgpu 0.20 with custom WGSL shaders for all rendering. Every pass below maps to a shader that exists in Core/Src/renderer/.

Render Passes

1. Terrain — instanced chunk geometry with per-fragment lighting and distance fog (shader.wgsl)
2. Sky — procedural sky with sun/moon and day/night cycle (sky.wgsl)
3. Animals — instanced voxel bodies with procedural walk animation (animals.wgsl)
4. Weather — rain/snow particles (weather.wgsl)
5. UI — HUD, inventory, crafting, text overlays (ui.wgsl, ui_sprite.wgsl)
6. Text — glyph rendering (text.wgsl)

Lighting Model

• Sun — directional N·L with day/night cycle
• Moon — soft ambient at night
• Fog — distance-based in the terrain shader (16 references in shader.wgsl), sky-colored
• Per-fragment lighting — Blinn-Phong-style N·L + specular for blocks and creatures

Geometry

Procedural 3D primitives generated by pure math (no model files needed):

• Sphere — UV sphere with configurable rings/stacks
• Cylinder — lathed with end caps
• Capsule — cylinder + hemisphere ends
• Cone — lathed with base cap
• Box — unit cube

All shapes carry smooth per-vertex normals for organic creature bodies.

Texture Pipeline

• texture_registry.rs conventions: blockname.png (all faces), blockname_side.png (side override), _top/_bottom variants
• Dynamic atlas (dynamic_atlas.rs) — MeMLP-generated procedural textures are uploaded into the atlas at runtime
• Bilinear upscale + grain for close-up detail
• AI texture styles selected by the MeMLP TEXTURE_ARCH head (8→12→6)

Shaders (as shipped)

Shader	Purpose
shader.wgsl	Main terrain + block rendering, fog
sky.wgsl	Procedural sky, sun/moon
weather.wgsl	Rain/snow particles
animals.wgsl	Voxel creature rendering + walk animation
text.wgsl	Text/glyph rendering
ui.wgsl	HUD elements
ui_sprite.wgsl	Sprite rendering

Performance

• Instanced rendering — one draw call per shape per chunk
• World mesh cache — invalidation on block changes (invalidate_world_mesh_cache)
• No per-frame allocations on the hot path
• Low-end PC mode — low_end_pc setting reduces render radius via performance profiles
• Configurable load_radius / render_radius / cleanup_radius

Planned (not in this build)

GLB model loading, mesh decimation and skeletal skinning for AI-generated creature models — designed, not implemented. Today's creatures are animated voxel compositions.