Chapter 1: Family Planning

Created by Sarah Choi (prompt writer using ChatGPT)

Family Planning (S / M / L, Economy / Premium) for Prop Concept Artists

Prop families are design ecosystems. Planning a set that scales across S/M/L and spans economy to premium trims is not a cosmetic exercise but a structural one. It asks you to define what is invariant—the language, interfaces, attachment points, and workflows—and what is variant—capacity, feature density, and finish. When done well, a family looks inevitable, behaves modularly, and reads consistently from thumbnail to close‑up. This article translates family planning into depiction and production practices focused on size ranges, sets, and attachment logic.

Every family begins with a core proposition. Decide what the objects do across all sizes and trims and state the promise in a single sentence. A scanning family might promise “fast field identification with optional lab‑grade verification.” A storage family might promise “impact‑safe carry with dock‑to‑bench handoff.” This promise guides the invariants: handle positions that teach the hand, datum faces that teach the camera, and interface standards that make upgrades plausible. In concept sheets, express the proposition visually in a single hero panel where S, M, and L appear side by side against a human silhouette; this gives reviewers an immediate read on scope and cohesion.

Size ranges should be defined by use cases, not arithmetic scale factors. The small unit solves immediate, personal‑scale tasks and favors one‑handed operation and pocket or sling carry. The medium unit suits two‑handed work or shared use and introduces shoulder or belt interfaces. The large unit is team or vehicle scale and transitions to two‑person carry or fixed mounts. Instead of scaling all dimensions equally, anchor scaling to critical ergonomics and payload constraints. Preserve grip diameters, control spacing, and interface geometry across sizes, while allowing chassis length and capacity to stretch. This creates visual continuity while avoiding tiny, unusable controls on the small and bloated, clumsy controls on the large. In production notes, include a size table listing constants and variables for each SKU—constants include handle section, fastener gauges, and connector standards; variables include chassis length, battery count, and bay volume.

Attachment points are the family’s connective tissue. Standardize a grid or a pattern that appears across sizes: a three‑point dovetail, a 30 mm bolt circle, a twin‑rail with keyed stops, or a textile lattice compatible with webbing. The geometry must support both economy and premium trims so accessories are interoperable. Define a datum hierarchy with names—A‑face on the left, B‑face top, C‑face rear—and make the main attachment live on A‑face across the family. This keeps docks, brackets, and holsters compatible and lets animation reuse approach logic. In your paintovers, draw the attachment silhouette in high contrast and show a ghosted accessory sliding on; in production, add callouts for tolerances, clearances, and fastener access with tool vectors so the interface is buildable.

Economy versus premium is not only about materials; it is about capability, service model, and emotional tone. Economy trims emphasize robustness, manufacturability, and simple service. They broadcast wider tolerances with larger edge radii and fewer parting lines, and they invite field repair with exposed fasteners and gasket reveals. Premium trims emphasize precision and feature density. They tighten panel gaps, hide fasteners, integrate lighting, and add secondary textures where fingers land. The family should present these differences without losing its DNA. One strategy is to keep the same skeleton and vary skins and modules: economy uses an ABS shell with visible ribs and mechanical latches; premium overlays magnesium or carbon skins with elastomer gaskets and magnetic assist latches. Another strategy is capability partitioning: economy shares the interface but ships with blank plates where premium mounts sensors or power couplers. Narratively, economy belongs to frontline crews and civilians, premium to specialists and command; showing both in the same scene immediately explains class and role without labels.

Visual language is the glue. Choose a few signature moves and repeat them across sizes and trims. A double chamfer along the A‑face that catches light, a shallow thumb index around primary controls, a rib cadence that matches fastener spacing, or a color break that frames the interface all become family DNA. These repeats allow the family to survive texture compression and distance. When you add premium features, keep the cadence intact; a lit ring should sit inside the same chamfer that appears unlit in economy. When you add economy ruggedization, retain the silhouette cues; a rubber bumper should echo the edge break rather than erasing it.

Sets are how families ship and how players read value. A small and a medium can ship as a field pair with shared batteries and cross‑docking, while the large serves as a base. Depict sets as nested ecosystems: the small nests into a bay on the medium, the medium nests into a rack on the large, and accessories clip to all three. In concept, show a sequence panel where the small docks into the medium and power/data icons handshake. This sequence should be believable if the world supports smart interfaces, and equally believable if the world is analog; include alignment keys and latch geometry so it reads either way. In production, provide mating diagrams with tolerances and a brief note on latch throw, detent force, and alignment chamfers so animation can sell the snap.

Backwards and forwards compatibility are family ethics. Design new generations to mount on old docks and old accessories to mount on new shells where plausible. This implies maintaining datum positions and reserve space in the silhouette for future modules. If the fiction requires a break in compatibility, telegraph it distinctly—a new rail profile, a shifted bolt circle—and offer an adapter plate in‑world. This duality is narrative gold: adapters signal scarcity, black‑market ingenuity, or institutional inertia. On the sheet, include a small callout showing Gen‑1 on a Gen‑3 dock with an adapter; it makes your world feel layered.

Tolerances and manufacturing stack‑ups must be considered at the family level. The interface needs enough clearance to work across all molds and materials, which drift with size. A dovetail that is crisp in premium magnesium may stick in economy ABS after paint buildup. Solve this with generous lead‑ins, relief pockets, and surface spec separation: critical sliding faces receive tighter processes and secondary faces take paint or texture. Note these in production with “critical‑to‑function” flags and a process note: machine after paint, mask during coating, or use a sacrificial bushing. Keeping the interface constant allows a single jig set to serve all sizes, which is both a worldbuilding detail and a production simplifier.

Capacity and power scaling often drive size classes. The small carries one cell and one bay, the medium two cells and two bays, the large four and a generator tap. Rather than inventing new battery formats per size, keep the cell form factor constant and vary count and arrangement. This lets the viewer recognize swaps and creates diegetic economies: squads trade cells and scavenge from wrecks. Present an exploded view showing the same cell cassettes across S/M/L. In premium SKUs, embed smart pack IDs and status windows; in economy, use stamped arrows and mechanical interlocks. The shared cassette becomes a prop in its own right and ties the family together.

User posture and carry systems must be planned for each size and trim. The small should ride on chest or forearm mounts, the medium on belts or shoulder straps, and the large on back frames or vehicle cradles. Keep mounting geometry consistent so a single strap or plate can serve multiple SKUs. Provide comfort stack‑ups in production—pad thicknesses, strap widths, and adjust ranges—and ensure that the silhouette shows load paths honestly. A family that is comfortable in its mounts feels engineered rather than decorative.

UI and affordance placement must scale with size without breaking habit formation. If the primary trigger sits under the index finger on the small, the same relationship should exist on medium and large, even if the physical distance increases. Displays should grow in pixel count and legibility but retain hierarchy and icon locations. Premium trims add redundancy—haptic ticks, LED arcs, or audible detents—while economy trims rely on mechanical detents and printed icons. Show the same UI in three sizes on one panel to prove that the mental model survives scaling; include a top view showing indexing features for gloved use.

Finish strategies communicate price tier at a glance. Economy paints and textures should be selected for durability and repairability—thicker textures that hide scuffs, color molded plastics, and replaceable boots. Premium finishes can lean on tighter textures, subtle metallics, and precise edge breaks that throw crisp highlights. Both should share a palette family: choose a neutral body color, a functional accent for interfaces, and a tier accent used sparingly. A premium blue ring around the interface becomes a gray molded ring in economy; the geometry stays the same. This keeps brand recognition while supporting budget storytelling.

Service and failure logic must be consistent across the family. Economy should surface fasteners and gaskets so field techs trust the device and can service it with generic tools. Premium can conceal fasteners behind covers but must show service paths—lift tabs, alignment marks, and fold‑out panels. Across sizes, show where wear accumulates and keep it believable: polish where hands land, grime in recesses, paint chips at corners, and elastic sag at straps. The same wear vocabulary, scaled, makes the family feel like a real line seen at different ages and duty cycles.

Kits and SKUs should be mapped explicitly. Create a family matrix: rows are sizes, columns are trims, cells list standard modules and optional accessories. Conceptually, present the matrix as a small infographic on the sheet, but keep the story in paragraphs for readability. Production can mirror this matrix in file naming and variant management. Clarify which meshes are shared sub‑assemblies and which are trim‑specific shells; this reduces rework and ensures that texture atlases can be shared where possible. If your pipeline supports it, align UV islands for shared parts so materials can swap without re‑unwrap.

Camera and LOD strategy should be planned with the family. If gameplay shows the small unit in hand and the large unit as background furniture, scale the microdetail accordingly. The small receives higher‑frequency textures and crisp knurls; the large relies on silhouette, rib cadence, and light‑catching chamfers visible at distance. Premium variants can keep more microdetail at range via emissive accents and chamfer highlights; economy relies on bolder breaks. Align these choices with LOD budgets so the family does not flicker between identities at distance.

Narrative positioning emerges from family contrast. A scrappy resistance might field economy smalls and mediums with patched adapters connecting to captured premium larges. A corporate faction might deploy all premium with custom colorways and serialized plates. A black‑market ecosystem might mix premium cores with economy shells. Help the viewer decode these stories by keeping interfaces constant and letting materials and modules tell class. Include one panel where a premium and an economy unit share the same dock; this single image communicates the entire strategy.

Testing your family is concrete and quick. Print scaled silhouettes of S/M/L and stage them next to a mannequin or character paintover. Check hand reach to controls, sight lines to displays, and dock approach angles. Swap accessories between sizes to verify your interface. Photograph the process and paste snapshots into your sheet margins as evidence; the audience will feel the rigor even if they don’t read every number.

Production handoff turns the vision into reusable assets. Provide orthographic views for each size with shared dimensions highlighted in a single color and variable dimensions in another. Supply interface drawings at 1:1 scale with tolerances, datum labels, and tool approach arrows. Include an exploded view of the shared sub‑assemblies and a BOM that marks which line items are common across SKUs. Add notes on finish specs and masking zones so tiers can be manufactured without retooling the entire paint process. State explicitly which parts are backward‑compatible with prior gens and what adapters exist. With this packet, modeling can build variants efficiently, rigging can reuse animation curves, and texture artists can share atlases across the line.

A well‑planned family feels like a living product line in a living world. The S/M/L sizes solve distinct tasks while teaching the same hand movements; the economy/premium trims speak to class, context, and budget without breaking interoperability; the attachment points and datum faces make kits grow with player needs. When sets, size ranges, and interfaces cohere, your props stop being isolated objects and become a believable ecosystem—pieces that belong together because they were designed together.