# ADR-0016: 24,000-triangle character budget

- **Status:** Accepted
- **Date:** 2026-11-05

## Context

ADR-0015 raised the character contract to 16,000 triangles / 16,000 glTF
vertices for the MakeHuman head, hands and crowd variety. The local MPFB
full-body prototype now uses that head, project hands and shoes, and a fused
neck: it measures 19,747 triangles before any clothing variation. The 16,000 cap
leaves no room for the firefighter and hoodie gear, and it forces the body and
neck into a low decimation that produces visible facets.

## Decision

Raise the character contract to **24,000 triangles / 24,000 glTF vertices** per
character (`CHAR_MAX_TRIS`/`CHAR_MAX_VERTS`, `npc_pipeline.MAX_TRIANGLES`/
`MAX_VERTICES`, and the `adapt` defaults). The 13 core bones, five tint slots,
front orientation, grounding and single `npc_base` skinned mesh are unchanged.
Gear stays at 1,500 triangles and props at 4,000.

## Consequences

- The MPFB body, accepted head and neck fit with headroom for the 12 clothing
  variants and future jacket/hoodie detail.
- The 24-NPC and Web frame-time budgets must be re-measured before shipping any
  variant built at the new cap; the extra geometry is not free.
- The procedural generator and the low-poly `npc_base` fallback remain valid;
  they are not required to use the new headroom.
- MPFB stays a local development tool. Production must bake a committed source
  GLB; CI and the build must not depend on MPFB.
- Historical reviews and measurements that state 16,000 remain accurate for the
  date they were recorded; current contract documents state 24,000.

## Alternatives

- **Keep 16,000 and decimate the MPFB body further:** rejected because the neck
  and shoulder already show facets and the clothing variants would exceed the
  cap.
- **Separate caps for the MPFB prototype and the shipped characters:** rejected
  because it creates a second contract and makes the rollout ambiguous.