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VIVIA — Rendering Pipeline

GPU Pipeline (wgpu)​

The renderer uses wgpu 0.20 with custom WGSL shaders for all rendering:

Render Passes​

  1. Terrain — instanced chunk geometry, per-fragment lighting
  2. Sky — procedural gradient with sun/moon, ACES tonemapping
  3. Animals/Mobs — instanced voxel bodies with walk animation
  4. GLB Models — loaded AI-mesh models with procedural skinning
  5. Weather — rain/snow particles (disabled for performance)
  6. UI — HUD, inventory, crafting, text overlays

Lighting Model​

  • Sun — directional N·L with day/night cycle
  • Moon — soft ambient at night
  • Specular — Bln-Phong for wet skin, shells, ice, metal
  • Emission — glow for eyes, crystals, lava
  • Fog — distance-based, sky-colored, matches terrain/mobs
  • Tonemapping — ACES (Narkowicz approximation) in linear space

Geometry​

Procedural 3D primitives generated by pure math:

  • 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 have smooth per-vertex normals for organic creature bodies.

GLB Model Pipeline​

  1. Load raw GLB (tripo/meshy AI exports)
  2. Weld duplicate vertices
  3. Decimate to ~6K triangles (meshopt, 2% threshold)
  4. Bake triplanar UVs from positions + normals
  5. Generate procedural skin texture per creature type
  6. Cache to ~/.local/share/nv2/mesh_cache (keyed by GLB hash)
  7. Upload vertex + index buffers to GPU

Shaders​

ShaderPurpose
shader.wgslMain terrain + block rendering
sky.wgslProcedural sky, sun/moon, aurora
weather.wgslRain/snow particles
animals.wgslVoxel creature rendering + walk animation
model.wgslGLB model rendering + procedural gait
text.wgslText/glyph rendering
ui.wgslHUD elements
ui_sprite.wgslSprite rendering

Performance​

  • Instanced rendering — one draw call per shape per chunk
  • 2048 cube instances max (creatures)
  • 256 AI mesh instances max (GLB models)
  • Bilinear texture upscale + high-frequency grain for close-up detail
  • Deterministic mesh cache — instant restart (0.3s from cache)
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