Chapter 2: Theme Packs & Faction Variants

Created by Sarah Choi (prompt writer using ChatGPT)

Theme Packs & Faction Variants — Prop Sets & Ecosystems at Scale

Why Theme Packs Matter

Theme packs translate art direction into reusable production systems. For prop concept artists on both the concepting and production sides, a theme pack is a portable bundle of grammar—shapes, edges, materials, palettes, symbols, wear patterns, and placement rules—that lets teams dress interiors and exteriors coherently at scale. Faction variants then apply that grammar to different cultures, brands, or organizations so the same gameplay kit can inhabit multiple identities without duplicating work or blowing budgets. Done well, theme packs increase throughput, keep visual noise in check, and make reuse the default.

Definitions (So Everyone Uses the Same Words)

  • Theme Pack: A documented set of visual rules and prefabs that govern a location or brand. Includes kits, material packs/atlases, decal libraries, signage, and placement heuristics.
  • Faction Variant: A targeted reskin of a theme pack that changes identity without breaking silhouettes, metrics, or sockets. Usually swaps materials, decals, trims, and a small number of silhouette parts.
  • Role Taxonomy: Anchors → Structurals → Utilities → Decoratives → Scatter. Every pack lists which kits populate each role.
  • AMF Ratio: Anchor–Mid–Filler counts per area tile (e.g., per 20×20m).
  • Bands: Distance readability bands mapped to LOD tiers (A: 0–5m, B: 5–20m, C: 20m+).

Anatomy of a Theme Pack

A shippable pack should contain:

  1. Grammar Sheet: Shape language (round vs. angular), edge softness bands, fillet sizes, panel gap ranges, fastener families, and silhouette rules.
  2. Material & Palette: Atlas memberships, legal shader models, roughness/albedo ranges, emissive usage, and 3–5 canonical palette chords (dominant, neutral, accent, hazard, UI).
  3. Decals & Signage: Iconography, typography hierarchy, color‑blind‑safe codes, stenciling rules, number/letter ranges, and do‑not‑use examples.
  4. Kits: Modular parts for anchors/structurals/utilities/decoratives. Each part has nominal dimensions, sockets, allowable scale, and red lines.
  5. Placement Heuristics: Interior/exterior rules (clearances, no‑friction lanes, sightline cones), AMF ratios, and density governors.
  6. LOD Survival: What remains per band, proxy swaps, and bake/trim conversion rules.
  7. Variant Matrix: Trim levels (base, ruggedized, premium), colorways, grime envelopes, and safe randomization.
  8. Streaming/Performance Notes: Per‑tile material slot budgets, emissive count caps, reflection probe density, and light/fog allowances.

Designing Faction Variants Without Re‑authoring Everything

Factioning is a system, not a repaint. Start with protected constraints: metrics, sockets, interaction pivots, and shared kits must not change. Then define mutable layers:

  • Materials: Swap between curated material packs (e.g., Painted Steel → Cerakote; Brushed Alu → PVD; Canvas → Waxed Canvas). Keep UVs and atlas indices stable.
  • Decals: Replace iconography and text families; maintain size ranges and placement zones.
  • Trims: Exchange edge trims, screw families, and gasket colors to shift feel without re‑modeling.
  • Motifs: Add light inlays, weave patterns, or embossed logos where legal.
  • Wear System: Adjust wear generators: dust vs. oil bias, chip size, scorch direction, and value shift.

The trick is to publish a variant envelope per element (e.g., “+/– 10 gloss units, +/– 8% saturation”) so production can recolor safely and automated reskin tools can run without art‑director babysitting.

Example: One Pack, Three Factions

Imagine a base Transit Hub theme pack. The same kits dress three factions:

  • Corporate Clean: Tight radii (R6–R12), low contrast, satin materials, pale neutrals with limited accent (safety cyan). Decals are crisp sans‑serif, small warning icons, subtle backlit inlays.
  • Frontier Industrial: Larger chamfers (R2–R6), exposed fasteners, painted steel with rub‑through, rubber and bare alu, warm hazard orange. Decals are stenciled, mismatched, with maintenance stamps.
  • Cultic Bio‑Arc: Organic curvature blended with prismatic facets, translucent composites, oilslick sheens, deep greens/violets as accents. Decals become sigils/ornaments; emissives pulse.

All three factions keep the same bench, barrier, light pole, kiosk, and trash kit metrics and sockets. Only materials, decals, trims, and select silhouette add‑ons change.

Interior Dressing Rules per Faction

Interior logic must remain actionable for level art and outsourcing. For each faction, provide:

  • Clearance Metrics: Aisle widths, counter heights, reach zones. Corporate: 1.4m aisles; Frontier: 1.2m min with overflow bins; Bio‑Arc: 1.3m with soft partitions.
  • Wall Rhythm: Corporate: panels at 1.2m stud rhythm; Frontier: modular frames 1.0m with exposed brackets; Bio‑Arc: continuous shells with ribbing every 1.6m.
  • Ceiling Budget: Corporate: minimal ceiling noise; Frontier: denser ducts/cable trays; Bio‑Arc: veined light runners (cap emissives per tile).
  • Affordances: Corporate: touch panels flush with frames; Frontier: lever/valve reads always visible; Bio‑Arc: contact pads glow at low frequency.
  • AMF Ratios (per 10×10m room): Corporate 1/4/12; Frontier 1/5/16; Bio‑Arc 1/3/10 (wider anchors).

Exterior Dressing Rules per Faction

  • Ground Plane: Corporate: clean pavers with maintenance seams; Frontier: patched asphalt and plates; Bio‑Arc: growing substrate with integrated drainage.
  • Shade/Cover: Corporate: tensile canopies; Frontier: corrugated awnings; Bio‑Arc: semi‑translucent fins.
  • Skyline Punctuation: Corporate: signage pylons and antenna masts sparse; Frontier: cranes/stack vents frequent; Bio‑Arc: spires and light organs (cap at 1 per 30m).
  • No‑Friction Lanes: 3–4m clear path across plazas; mark preferred approach cones so anchors are visible over mid clutter.
  • AMF Ratios (per 20×20m tile): Corporate 1/6/24; Frontier 1/8/32; Bio‑Arc 1/5/18.

Palette, Value, and Contrast Discipline

Publish value ladders for each faction: base/trim/hazard/UI. Corporate stays in tight value bands; Frontier allows broader contrast with chipped paint revealing brighter unders; Bio‑Arc uses narrow albedo but strong emissive accents. Provide color‑blind‑safe codes for signage and hazard language and ensure the same hues map to the same functions across all factions (e.g., yellow = mechanical hazard, cyan = interaction). Consistency reduces QA churn.

Material Packs and Atlases (Reuse Wins)

Lock each faction to a material pack with atlas assignments:

  • Corporate_MatlPack_v1 (satin alu, powder‑coat white/gray, frosted glass, rubber).
  • Frontier_MatlPack_v1 (painted steel A/B, brushed alu, oiled rubber, poly tarp A/B).
  • BioArc_MatlPack_v1 (pearl composite, bio‑polymer, smoked glass, braided cable).

Document slot budgets (e.g., Anchors ≤ 3 unique mats; Mids draw from shared pack only; Fillers = decals/trim). Keep shader params uniform (roughness ranges, emissive nits), so cross‑faction swaps are cheap. Note packed UV conventions and texel density targets; include a fallback rule when unique textures are denied.

Decal Libraries and Typography Systems

Each faction gets a decal bank (icons, numbers, warnings, brand marks) with size tiers and mounting heights. Publish do‑not‑mix lists (Corporate type never on Frontier steel) and legal weathering per faction (Corporate decals stay crisp; Frontier stencils overspray; Bio‑Arc inlays bleed slightly). Include language‑agnostic alternates and ensure color‑blind safety.

Trim Levels and Safe Randomization

For every prop family, define trim levels and which layers swap:

  • Base: standard materials, no ornament, minimal decals.
  • Ruggedized: thicker trims, extra guards, darker palette, more grime.
  • Premium/Ceremonial: glossy or precious materials, engraved trims, more emissives.

Then give randomization rules: rotation steps, snap grids, colorway shuffles (A/B/C), grime envelopes (light/medium/heavy) and what never randomizes (sockets, hazard decals, interaction labels). Pair with proxy swaps for LOD (crate stack → single crate + decal → stain).

Interaction, VFX, and Audio Hooks by Faction

Keep beats consistent (closed → interact → resolved) but vary timbre:

  • Corporate: soft servo hums, white LEDs, two‑tone confirmation beep.
  • Frontier: mechanical clunks, steam puffs, amber indicator.
  • Bio‑Arc: wet thrum, bioluminescent flicker, chime.

Document state colors and blink cadence per faction; list budget caps (e.g., “Max 3 dynamic emissives per 20×20m tile”).

Performance & Streaming Guardrails

Publish per‑tile budgets and what to do when teams exceed them:

  • Materials: 24 slots hard cap; if exceeded, swap mids to shared trim/decal.
  • Lights/FX: Corporate 2 dynamic/8 static; Frontier 1/6; Bio‑Arc 2/6.
  • Reflection Probes: max 1 per 20×20m.
  • Animated Nodes: max 6 per tile.
  • Cross‑Cell Props: provide end‑caps and cable loops that terminate cleanly at cell borders.

Avoiding Cross‑Faction Contamination

Create a short contamination list: trims, screw heads, and colorways that never mix. Add neutral kits (utility pipes, safety rails) with faction skins, so when teams kitbash, they stay compliant. Include quick rules like “Corporate never exposes raw threads,” “Frontier never uses glossy white,” “Bio‑Arc never uses right‑angle corner guards.”

Authoring Workflow (Concept ↔ Production Loop)

  1. Concept Pass: Establish grammar, value ladder, 5–7 hero props, and a 20×20m dressed tile mock (interior + exterior).
  2. Kitization: Break heroes into kits with sockets and pivot logic; publish the variant envelope.
  3. Material/Decal Packs: Build atlas and decal sheets; test batch counts in an engine mock.
  4. Factioning: Apply material/decal swaps and minimal silhouette add‑ons; validate AMF ratios stay intact.
  5. LOD Maps: Author band survival and proxy swaps; run a perf sample on a dense tile.
  6. Validation: Dress two tiles per faction; hand to a different artist to replicate without direction.
  7. Lock & Ship: Freeze names, packs, and budgets; push to outsourcing with a checklist.

Outsourcing‑Ready Checklist (One Page)

  • Grammar sheet + do‑not‑do examples.
  • Kit orthos with sockets/pivots and legal scale ranges.
  • Material pack (atlas IDs, texel density, shader params).
  • Decal library (sizes, mount zones, file paths).
  • AMF ratios and placement rules (interior/exterior).
  • LOD survival and proxy table.
  • Variant matrix (trim levels, colorways, grime).
  • Performance budgets and fallback rules.
  • Naming conventions and file structure.

QA & Review Gates

Add automated checks where possible:

  • Naming/Slots: Prefab nodes and materials match the standard.
  • Atlas Compliance: No rogue textures; audit by script.
  • Distance Read: Band B silhouettes preserve faction identity; Band C retains skyline punctuation.
  • Signage Access: Hazard and UI labels are legible at intended camera.
  • Collision/Flow: No‑friction lanes remain clear after dressing.

Measuring Success

  • Consistency: Separate teams produce areas that look like siblings across factions.
  • Throughput: Time to dress a tile drops after pack adoption.
  • Performance: Material slots and draw calls remain within cap at higher densities.
  • Player Readability: Wayfinding improves; fewer bug reports on visual noise.

Final Thought

Theme packs and faction variants are the bridge between big‑picture art direction and moment‑to‑moment set dressing. When you publish a clear grammar, bounded variant envelopes, and actionable placement rules—while keeping materials and decals inside shared economies—downstream teams can scale worlds fast without sacrificing identity or performance.