Chapter 3: Steering, Suspension & Brakes

Created by Sarah Choi (prompt writer using ChatGPT)

Steering, Suspension & Brakes for Vehicle Concept Artists — Mechanics & Function 101

Steering, suspension, and brakes are the hidden choreography that turns power into control. For vehicle concept artists—whether you sit on the concepting side shaping fantasy or on the production side specifying reality—these systems decide locomotion feel, structural truth, and packaging constraints. They also drive the reads that matter at speed: how a vehicle leans, bites, squats, stops, and recovers. This article explains the essentials of kinematics and contact patches, shows how structure and packaging follow, and maps the deliverables that help indie and AAA teams build fast and right.

Steering converts driver intent into wheel angles and lateral force at the ground. The visible story begins with kingpin or steering axis inclination, caster, and scrub radius, because these angles control self‑centering, road feel, and how the tires sweep inside the fenders. In concept exploration, you imply these parameters with the stance of the front upright, the rake of the strut or double‑wishbone, and the size and position of the steering rack. In production packages, you place steering pivots relative to wheel centers and define maximum steer angle at bump, droop, and ride height so modelers, riggers, and physics teams do not guess. Four‑wheel‑steer variants require explicit rear toe mechanisms and articulation envelopes that avoid interpenetration with exhausts, batteries, or tanks. On mechs and walkers, the analogy is hip yaw and ankle roll: the same kinematic logic applies to keep feet pointed where the body needs to go without shearing contact.

Suspension keeps the tire in its performance window across bumps, load transfer, and attitude changes. Kinematics describe how wheels move in space: camber gain, toe change, roll center migration, anti‑dive under braking, anti‑squat under acceleration, and bump steer given steering and vertical travel. In concept, you express kinematics through control arm lengths, pick‑up point heights, and the relation of springs and dampers to those arms. A long, low upper arm suggests gentle camber gain for high‑grip tarmac; a short, steeply angled arm suggests quick camber response for rough terrain. Torsion bars, coilovers, pushrods with rockers, and air springs each imply different packaging volumes and maintenance stories. On hover or VTOL craft, suspension analogs are gimbal ranges and vectoring margins; you still design for attitude control and gust response, just with emitter spacing and thrust vector envelopes instead of springs.

Brakes convert kinetic energy into heat at contact patches and rotors, and the packaging is non‑negotiable. In concept, the size of the brake disc or drum, caliper placement, and cooling path through wheels and ducts tell the truth about duty cycle and mass. Heavy, fast vehicles demand large rotors with multi‑piston calipers and clear airflow to avoid fade; off‑road designs protect rotors and lines behind shields but risk heat buildup, which you must solve with vents and scoops that do not fill with debris. Regenerative braking on electric and hybrid drivetrains shifts some work to motors but never erases the need for friction brakes sized for emergency stops; your callouts must state regen levels and the handoff to hydraulics so audio, UI, and VFX can stage state changes.

The contact patch is the only part of a wheeled vehicle that matters to the ground, and its behavior should govern silhouette and proportion decisions. The patch grows and shrinks with load, camber, inflation, and surface; its orientation decides grip and slip angles. When a design promises agility, you show generous tire sidewall stiffness, supportive camber gain in bump, and fender arches that allow the wheel to stay upright relative to the road during roll. When a design promises comfort or load capacity, you show taller sidewalls, longer control arms for compliance, and damper reservoirs that signal heat management on long cycles. On tracks, the patch is a band across multiple bogies; you design idler and drive sprocket sizes, road wheel count, and torsion arm spacing to keep the band flat and to distribute load over soft ground. On skids, skis, or lander pads, the patch is a pressure footprint that grows with area; you express this through pad geometry and deployment stance.

Structure follows suspension loads. Control arm pick‑ups and subframes need rigid, triangulated paths into the body shell; when you place arms in cutaways, you also imply where bulkheads, nodes, and weldments must sit. A strut tower is a tower in silhouette for a reason: it carries vertical and lateral force directly into the chassis. Double‑wishbones require horizontal spread and produce low hoodlines; multi‑link rear ends need room for toe links, trailing links, and coilover mounts without colliding with trunks or battery packs. Live axles in 4×4 builds require clearance for pumpkin travel and robust trailing link mounts; independent suspensions trade articulation for unsprung mass reductions and camber control. Air or hydraulic systems add compressors, accumulators, and reservoirs that need cool air, service access, and mounts that can take pulsation; your orthos and callouts must carve that space honestly.

Packaging is the art of giving every part the room it needs without breaking proportion or read. Steering racks need to clear oil pans or battery modules; half‑shaft plunge must be safe at maximum steer and bump; sway bars need arcs that do not hit undertrays; damper tops need to avoid canopy hinges; brake ducts need inlets and exits that do not starve at yaw. In front‑drive layouts, cooling stacks crowd the rack; in rear‑drive, the propshaft and tunnel crowd rear damper mounts; in e‑axle designs, the inverter and gearbox housings crowd half‑shaft articulation. Off‑road packaging must allow jounce and rebound that can double road‑car travel; fender lips, body seams, and flare thicknesses must respect this with daylight that remains visible at game camera distances. The best concept pages make these conflicts visible early so production does not back into dead ends.

Kinematic compromises are where design and gameplay negotiate. A vehicle that reads extremely low and wide might need generous anti‑dive and anti‑squat to keep attitude changes believable under heavy braking and boost; you reflect these choices with control arm angles and damper positions that visually support the behavior the camera will show. A high‑clearance crawler needs huge articulation without tire‑to‑body collision; you widen arches, shorten overhangs, and add generous bump stop volumes and jounce straps in callouts, then verify by placing the proxy in extreme poses at the intended camera FOV. A VTOL landing leg system that promises soft touchdowns needs stroke, preload, and damping hints; you show nested sleeves, visible nitrogen canisters, and foot geometry that reads compressive stability.

Braking reality drives exterior reads more than many artists expect. Real airflow to rotors often comes from under‑bumper or wheel‑well scoops rather than giant grille openings; side intakes can feed rear brakes and diffs if ducted clearly. In wet or dusty environments, ducts must be placed to avoid packing; you can show baffles or mesh screens and call them out so modeling does not texture a fake opening. Brake glow is a performance and readability trick, but it should light only the rotor edges at heavy loads; your camera‑read boards can demonstrate when and how this appears so VFX and lighting do not wash out negative space.

On the production side, numbers turn drawings into instructions. Steering needs rack travel, ratio, and maximum angles at multiple ride heights; suspension needs bump and droop travel, spring rates or their analog, damper stroke and packaging length, roll center targets, and pivot coordinates in project units; brakes need rotor diameters and thicknesses, caliper envelope dimensions and clocking angles, line routing zones, and duct cross‑sections. These values live on the callout pages next to the orthos and in the metric sheet, and they bind to hierarchy names so rigging and physics can connect without translation errors. Cutaways and exploded views then clarify service access and assembly order: where the damper exits the body, where the rack mounts, how the hub carrier assembles, and how brake shields and ducts sandwich around the knuckle.

Camera reads ensure all this work survives in play. You preview the silhouette at far, mid, and near distance bands at the intended FOV and under representative lighting and VFX. You test lean angles under acceleration, braking, and cornering so the outline does not collapse into a flat blob or clip through level geometry. You test wheel arch gaps, damper exposure, and brake glow for clarity, then hand those images to lighting, VFX, and audio so tire squeal, dust plumes, and rotor hiss sync with the way the vehicle looks and moves. If you are designing for cockpit view, you also test steering wheel angle versus driver hand animation and the visibility of suspension motion in open‑wheel designs, adjusting gauge placement and pillar thickness to preserve sightlines.

Indie and AAA workflows change cadence but not truth. Indie teams often iterate steering, suspension, and brake reads directly against greybox handling, painting over screenshots to adjust wheelbase, rack placement, arch cutouts, and ducting until play feels right. They compress deliverables into a single evolving canvas with measured side view, a quick cutaway, and targeted callouts. AAA teams separate artifacts by gate: silhouette and stance lock in pre‑production; kinematic layout lock with measured pick‑ups and travel envelopes before modeling kickoff; rigging check with exploded assemblies and pivot hierarchies; camera‑read sign‑off with distance boards; and optimization passes where LODs preserve control arm landmarks, damper tops, and brake mass so readability survives.

From the concept seat, success means drawing motion you can defend. Your silhouettes and cutaways must imply steering and suspension choices that physics can make true; your brake and duct layouts should convince audio and VFX where to locate heat and sound. From the production seat, success means frictionless handoff. Your orthos and callouts give exact pivot coordinates and travel ranges; your hierarchy notes keep animations stable; your change logs prevent divergence across variants and skins.

Closing the loop: vehicles are only as convincing as their contact with the world. When steering geometry, suspension kinematics, and brake capacity align with the role and stance you’ve promised, players feel it even if they cannot name it. Encode those truths early, show them clearly, and protect them through production. The result is locomotion that looks right, handles right, and reads right at speed.