Chapter 2: Car Classes & Proportion Templates

Created by Sarah Choi (prompt writer using ChatGPT)

Car Classes & Proportion Templates for Vehicle Concept Artists — Land Vehicles: Wheeled

Cars are proportion machines. Long before materials or micro‑detail, players read class, price tier, and purpose from wheelbase, overhangs, greenhouse size, beltline height, and stance. For vehicle concept artists on both the concepting and production sides—across indie speed and AAA scale—class templates turn taste into repeatable decisions. This article maps the common road‑car families—compact, sedan, coupe, SUV, and pickup—explains how their proportions differ from bikes and trucks, and shows how to encode those differences into deliverables that modeling, rigging, lighting, UI, VFX, audio, and marketing can trust.

Designing cars alongside bikes and trucks requires a shift in mental model. Motorcycles bind human ergonomics directly into dynamics, so the rider triangle dominates silhouette. Trucks are payload and frame first; wheelbase steps, axle counts, and ladder rails set the story. Passenger cars live in the middle: their frames and suspensions matter, but visual identity and usability are driven by cabin geometry, luggage volume, and safety envelopes wrapped around a chassis that hides beneath skins. Your goal is to make those hidden constraints legible through proportion and stance so players instantly distinguish a compact from a coupe, a sedan from an SUV, a pickup from an SUV‑based ute.

Compacts are the most space‑efficient road cars and read as short, upright, and friendly. The wheelbase sits at the lower end of the family, front and rear overhangs are brief, and the greenhouse is relatively tall with generous glass and a low beltline. Track width is modest relative to body, encouraging rounded shoulders and minimal flare. The hood is short because transverse engines and compact cooling stacks dominate, and the rear hatch often cuts steeply to preserve cargo volume over length. In concept exploration, the stance leans toward planted but approachable, with minimal rake and a wheel‑to‑body proportion that tolerates smaller diameters without appearing under‑shod. In production, compacts reward precise orthos with scale bars tied to door aperture heights and seat H‑points, because usability is the product. Camera reads prefer strong C‑pillar geometry and clear headlight and DRL signatures that stay legible at city chase‑cam distances.

Sedans are three‑box proportion statements—engine bay, cabin, trunk—and they project maturity and stability. The wheelbase stretches relative to compacts to generate rear legroom and a calmer ride, while overhangs lengthen to host crush structures and trunk volume without breaking parking constraints. The greenhouse lowers and lengthens, beltlines rise slightly, and the roof arc finds a long, shallow crown that reads quiet speed. Good sedans avoid slab‑sided monotony by using subtle shoulder planes and generous door radii without surrendering the three‑box clarity. On the concept side, a side‑view silhouette that locks A‑, B‑, and C‑pillar positions will solve most downstream arguments; on the production side, orthos should place seat H‑points, beltline height, and door cut arcs with hinge and latch coordinates so animation and rigging can stage clean door motion. Camera‑read boards must demonstrate that taillight signatures are distinguishable across trims since sedans often share skins within platforms.

Coupes compress volume into drama by shortening rooflines and tightening greenhouses. The wheelbase can match the sedan sibling or shorten slightly, but the key move is a faster roof rake and a longer door that lets the B‑pillar slide rearward. Overhangs may shrink for sportiness or grow for grand‑touring presence, but either way the relationship of wheel diameter to body height tightens and fender flare becomes a stronger character cue. The coupe’s negative space under the rocker and in the rear quarter window must remain generous or the car will look heavy and slow. On concept pages, a three‑quarter hero paintover that tests roof thickness, beltline climb, and quarter light shape at the actual in‑game camera distance will resolve elegance versus aggression faster than any amount of detail. Production packages should freeze glass openings and seal profiles early so modeling can preserve silhouette while integrating door glass drop and frameless constraints. Rigging benefits from clear hinge arcs on long doors that avoid collision with curb and fender volumes.

SUVs are mass and utility wrapped in familiarity, and they tend to live on raised ride heights, taller greenhouses, and longer rear overhangs for cargo. Proportionally, the wheelbase expands to stabilize the higher center of gravity, track width widens to read planted, and the roof stays relatively level to accommodate rows of seats and roof racks. The beltline creeps up but must not erase side glass to the point of claustrophobia; successful SUVs balance safety with openness through tall door cutouts and strong C‑ and D‑pillar forms that keep the silhouette recognizable at distance. On the concept side, the stance should promise competence rather than aggression: generous wheel arch daylight at bump and rebound, honest approach and departure angles, and a tail volume that reads cargo without turning into a slab. On the production side, orthos must lock ride‑height bands, wheel‑arch chords, rear hatch hinge placement, and spoiler/third‑brake light geometry. Camera reads in mixed weather are critical here: fog, rain, and dust need to preserve taillight height and width cues on taller bodies.

Pickups are chassis statements that broadcast work and endurance. Their silhouette is a two‑box with a strong cab and a separate bed, and their proportions depend on wheelbase steps: single cab, extended cab, and crew cab stretch the cabin in discrete modules while the bed length moves in standardized increments. Overhangs remain practical—short front for approach, moderately long rear for step and tow—but the key read is the daylight between arch and tire at all loads and the relationship of beltline to bed rail height. A pickup that reads believable will show ladder‑frame logic in cutaways, exposed hitch and tie‑down hardpoints, and C‑pillar geometry that promises rollover strength. Concept exploration should emphasize class identity through grille height, hood crown, and fender mass rather than through cartoon lift; production packages must pin cab‑to‑bed gaps, tailgate hinge axes, and step geometry that clears bumpers and tow hooks. Camera reads should test empty and loaded states because bed height and rake shift with payload.

The bridge between cars and trucks is the crossover and ute, and proportion reveals lineage. Crossovers share car platform hardpoints but borrow SUV stance, so the wheel‑to‑body ratio must stay in passenger‑car ranges or the silhouette will look top‑heavy. Utes graft pickup beds onto car or SUV cabins, and the visual success depends on rear overhang design that preserves departure angle while giving believable bed volume. When designing across categories, protect the key ratios: tire diameter to body height, glass height to beltline, and overhang lengths relative to wheelbase. Breaking those quietly breaks class read.

Templates turn these readings into reusable rules. A compact template sets a short wheelbase band, small overhangs, tall greenhouse, and a friendly stance with minimal rake. A sedan template defines pillar positions, a measured three‑box, and a long shallow roof crown that functions across trims. A coupe template locks a fast roof and long door within the same wheelbase, tightening the glass‑to‑metal relationship and emphasizing shoulder. An SUV template establishes raised ride height, larger wheel diameter, and a near‑level roof with honest cargo tail volume. A pickup template sets discrete cab modules, bed lengths, and ladder‑frame daylight with wheel arch chords sized for articulation. These templates should ship as metric sheets in your project units, with scale bars, pillar coordinates, seat H‑points, beltline heights, door and hatch hinge axes, and wheel‑arch geometry at idle and compression. They become the scaffolds for both ideation and handoff.

Concept‑side practice benefits from painting proportion truths before detail. Begin each class exploration with a side‑view silhouette at scale, then test three stance variants by nudging wheelbase, roof crown, and overhangs within the class band. Move to a clay 3D block‑in to validate camera reads at the game’s FOV and distances, then paint over to set shoulder planes, glass thickness, and light signatures appropriate to class. Avoid using material contrast to solve proportion errors; a compact will not become a coupe by painting a faster roof—only a proportion shift will. When the class read sings at distance, fold in panel logic and material breaks that your faction or brand bible requires.

Production‑side discipline turns templates into speed. Orthographics must carry datum lines, scale, and coordinates for pillars, hinge posts, and latch plates so doors and hatches animate without collision. Cutaways should prove packaging: engine or battery placement, crash rails, HVAC paths, fuel or pack volumes, and spare tire wells, all sized to the class constraints. Exploded views provide assembly order for bumpers, lamps, glazing, and interior modules, with fastener logic that matches your studio’s kit. Callouts bind hinge arcs, clearance envelopes, seat travel ranges, and livery safe zones to actual numbers so implementation does not guess. Camera‑read boards must test far, mid, and near bands at day, night, and bad weather, because class recognition lives and dies in the outline when everything else is in motion.

Live‑ops and trim proliferation make proportion templates even more valuable. A budget compact and a sporty trim can share the same wheelbase and pillars while swapping bumpers, lamps, and wheels; a luxury sedan and a police interceptor can inherit the same three‑box while changing grille fill and livery; a performance coupe and a grand‑touring variant can share roof and pillars while adjusting tire and brake mass; an SUV family can scale from two to three rows by stretching the wheelbase within the class; a pickup lineup can move from short to long bed and from single to crew cab on the same frame with cab module swaps. Templates ensure these moves preserve silhouette and do not erode the class read.

Comparing back to motorcycles and trucks clarifies boundaries when classes blur. A coupe that steals too much motorcycle aggression with a hyper‑fast roof may erase rear headroom and shoot past its class promise; an SUV that borrows too much truck ladder logic may appear stiff and heavy unless its proportion pays off the added ride height with wider track and larger wheel diameter; a pickup that chases car sleekness may lose bed utility and tow posture, requiring a fiction that it is a lifestyle ute rather than a workhorse. Your faction and brand bibles should constrain these impulses with numeric guardrails so classes remain legible even as styling evolves.

Indie and AAA cadences differ in granularity rather than goals. Indie teams thrive on a single evolving canvas per class where silhouette bands, pillar positions, and packaging thumbnails live beside greybox screenshots and quick paintovers; decisions are made fast and recorded in a short change log. AAA teams split artifacts by gates: class template lock, platform and packaging lock, modeling kickoff with orthos and callouts, rigging check with door and hatch arcs, camera‑read sign‑off under lighting presets, and trim variation tests with livery. In both settings, a consistent naming scheme for classes, pillars, and hinge axes prevents drift across the fleet and the seasons.

Closing the loop means letting proportion lead. When a compact is short and upright, a sedan honest in three boxes, a coupe fast and taut, an SUV tall and level with real cargo, and a pickup modular and capable, players never have to think about what they are looking at. Your silhouettes will carry identity at speed, your cutaways will read like engineering, and your production packages will move cleanly through the pipeline. Build with class templates first, decorate second, and your world of cars will feel inevitable to drive—and impossible to misread.