Chapter 1: Reticles & UI Logic

Created by Sarah Choi (prompt writer using ChatGPT)

Reticles & UI Logic (Diegetic vs HUD) — Aiming Systems & Targeting

Reticles are choreography for the eye. Whether etched in steel, floating in glass, painted by lasers, or rendered as AR widgets, they convert intention into alignment. For concept artists, this means shaping housings, optics, emitters, and iconography so aim states read instantly across camera distances and styles. For production artists, it means building reliable parallax behavior, LOD‑safe artwork, exposure‑robust shaders, and synchronized state machines that link recoil, zero, and target feedback. This article maps a practical language for irons, optics, lasers, and smart sights, with a focus on diegetic UI versus HUD overlays—and when to combine them.

1) Design Values: Clarity, Cohesion, and Calibration

Clarity means the sight picture remains legible under motion, recoil, bloom, fog, and glare. Cohesion means reticle style, color rails, and animation cadence match the faction’s visual system and the weapon’s role. Calibration means what the reticle promises is what the projectile (or effect) delivers: consistent zero, predictable drop marks, and honest cone of fire. Keep these three as north stars; flashy graphics that drift from physics erode trust.

2) Diegetic vs HUD: Two Channels, One Story

Diegetic UI lives on the object—etched irons, illuminated dots, holographic reticles, laser designators, lens proms. It grounds the fiction and anchors eye‑hand behavior. HUD UI sits in screen space—crosshairs, hit markers, aim assist arcs—guaranteeing readability regardless of camera or weather.

Use diegetic for primary aim feedback (what the muzzle is doing) and HUD for secondary information (ballistic prediction, team/target context). In high‑immersion modes, keep HUD minimal and let diegetic sights carry the load. In competitive modes, allow a hybrid: a crisp diegetic reticle augmented by a subtle HUD stabilizer that shows recoil return and spread. Concept sheets should show both paths and how they stack without contradiction.

3) Irons — Etched Geometry and Human Vision

Irons succeed by proportion. Front post thickness should subtend 6–12 MOA on a typical FOV so it’s visible without blotting out targets; rear notch width should leave daylight around the post to aid centering. Aperture sights favor a thin front post and a forgiving rear ring whose edge does not shimmer under aliasing. Chamfer sight edges and add anti‑glare serrations or bead‑blasts; avoid mirror‑like bevels that bloom under HDR. For night or low‑light variants, tritium or photoluminescent dots should be small and cool‑toned; too much glow becomes a HUD masquerade.

Production notes: author irons as separate LOD‑aware meshes so they don’t shimmer; use a high‑contrast value rail that survives fog and bloom; align bore and post in first‑person with sub‑pixel precision and provide an exaggerated but believable window in third‑person so intent reads from distance.

4) Non‑Magnified Optics — Reflex & Holo

Reflex sights (LED collimated) and holographics (prism/hologram) share jobs: fast acquisition, tolerance to imperfect cheek weld, and minimal occlusion. Design housings with chamfered windows, sunshades, and anti‑reflective coatings. Keep bezels thin but durable; step the top silhouette in terraces so the optic never forms a solid wall on the weapon.

Reticle grammar: a simple dot (2–4 MOA) for speed; ring‑dot for framing; chevrons or carets to suggest lead and drop. Avoid ultra‑thin lines that vanish under motion blur. Offer brightness tiers tied to exposure metering and add an auto‑adaptive mode that never fully whips the brightness—ramp over 200–300 ms.

Parallax: fake wisely. True parallax‑free is impossible; build a forgiving eyebox by clamping reticle drift within a small arc around the optical axis so off‑center dots don’t mislead. In third‑person, exaggerate window size slightly so the dot reads as a stable locus during aim.

5) Magnified Optics — Scopes & LPVOs

Magnification introduces eye relief, exit pupil, and reticle detail. Sculpts stocks and cheek risers to land the eye at the correct relief. Show diopter and magnification rings with glove‑friendly knurls. For LPVOs, design an illuminated center (dot or horseshoe) that behaves like a red dot at 1× and a hash ladder that appears legible at 4–8×.

Reticle types:

  • BDC ladders with consistent subtensions; annotate which hash equals what range for a given zero.
  • Mil/MOA grids for advanced holding; keep line weight uniform and reserve thicker posts for edge anchoring.
  • Christmas‑tree wind holds for long shots; keep dots sparse to avoid mocha‑foam noise.

Production: author reticles as vector atlas or signed‑distance fields (SDF) to preserve crispness across FOVs. Clamp line thickness in pixels so zoomed states don’t produce hairline shimmer. Tie scope parallax/black‑ring vignettes to camera offsets sparingly; heavy tunneling punishes accessibility.

6) Lasers & Illuminators — Painting Intent

Lasers are aim intent more than precision. Classify beams:

  • Visible pointers for close quarters; keep brightness capped to prevent wash.
  • IR designators/illuminators for NV modes; convey with cooler emissives and lens shutters.

Mount lasers low/near bore or consistently offset. Provide a converged zero distance and draw a faint parallax hint (two tiny ticks) so players don’t over‑trust at range. In fog or dust, simulate volumetric scatter subtly; beam light should not become a lightsaber unless fiction demands. Safety language: do not point lasers directly into the camera; angle lens flares away, and add shutter behaviors for “safe” states.

7) Smart Sights — Sensors, AR, and Ethics

Smart sights merge on‑glass diegetic UI with world‑anchored HUD. Features: rangefinding pips, drop arcs, lead prediction, threat boxes, friend‑foe tags. Keep restraint: show only the next decision‑making cue, not a sci‑fi spreadsheet. Favor low‑parallax on‑glass overlays that track the optic rather than the screen; for world annotations (targets, waypoints), stabilize with motion filtering and cap angular velocity to avoid nauseating jumps.

Battery & failure: every smart sight needs degraded modes. Concept a physical etched reticle that remains when power dies, and a visible battery widget that changes slowly. Error cases (sensor occluded, rain on lens) should produce believable artifacts—blur, droplet refractions—and a clean handoff to irons or passive mode.

Ethics & fairness: avoid perfect wall‑hacks. If threat boxes exist, make them range/LOS limited and telegraph to opponents with visible sensor emissions or lens iridescence. Competitive readability beats omniscience.

8) Reticle Color, Value, and Accessibility Rails

Color is seasoning, not substance. Set a minimal palette: cool‑white/cyan for neutral, amber for adhesive/utility, magenta for lethal only if consistent with faction. Back color with temporal patterns: breathing for idle, steady for aim, pulsing for lock. Provide color‑blind‑safe “shape redundancy”: dot + ring, chevron + tick, not color alone. Allow user brightness presets with a min pixel footprint (e.g., ≥2 px) so reticles don’t vanish on 1080p. Offer a “high‑contrast reticle” mode that adds a faint outline or shadow for bright‑floor maps.

9) States & Timing — From Raise to Recover

Define the aim state machine: stowed → ready → ADS (aim down sights) → fire → recover. Each state drives reticle behavior:

  • Ready: faint, desaturated, or smaller.
  • ADS: crisp, bright, stabilized; dot recenters with a short time constant.
  • Fire: brief expansion or brightness dip synced to recoil impulse.
  • Recover: easing back to center; cone‑of‑fire clamps close.

Keep these beats under 300 ms total for snappy play, longer for heavy platforms. Use the same event names for audio, haptics, and VFX to keep lockstep.

10) Zeroing, Ballistics, and Trust

If the game models drop, wind, or projectile speed, the reticle must mirror it. Provide zero distances per weapon and ammunition. In concepts, annotate which hash equals which range and tie to faction manuals or on‑gun engravings. In production, bind projectile data to reticle shaders so BDC marks adjust with ammo swaps. For shotguns or foam sprayers, show spread cones or curing footprints as diegetic decals that scale with choke or nozzle. For nets, preview canopy size with a brief mid‑air “star” ghost during pre‑throw.

11) Camera & Occlusion — Keeping the Window Open

The optic window is a stage. Avoid accessory stacks that wall off the top plane. Angle sunshades so they don’t box the view. In first‑person, maintain a sight box that occupies 20–35% of screen width at ADS; larger blocks peripheral cues, smaller loses readability. In third‑person, exaggerate optic windows slightly and keep negative space between stock, head, and optic so aim direction reads without muzzle flash.

12) Wet, Dust, Snow — Weathering the Sight Picture

Weather is a readability tax. Design hydrophobic coatings (subtle blue‑green hue), wipers, or lens hoods. Add droplet normals that affect the reticle subtly but never randomize it. In dust, lower bloom and increase reticle core intensity by a notch. In snow, auto‑invert reticle outline if background is over a value threshold. Keep all transitions smooth and capped to avoid flicker.

13) Multiplayer Fairness & Spectator Readability

What a shooter sees is not what an opponent sees. Opponents should read aim intent via lens iris, slight gimbal settle, or laser posture, not via screen‑space reticles. Spectator cams benefit from optional “coach mode” overlays—reticle projection into world space—to teach timings. Ensure hit markers and confirmation beeps follow clear delays; avoid instant wall‑to‑wall feedback that feels psychic.

14) Production Handoff — Assets, Atlases, and Budgets

Deliver:

  • Concept package: optic housing orthos, anti‑glare patterns, reticle variants with subtensions, brightness rails, failure states, and a storyboard (raise → ADS → fire → recover).
  • Asset bundle: lens meshes with correct normals and roughness, interior emissive planes, reticle SDF atlas, mask IDs for fingerprints/smudges, and socket locators for lasers/lights.
  • Shader specs: auto‑exposure hooks, brightness clamps, parallax drift limits, outline toggle for accessibility.
  • Animation notes: eye relief tolerances, reticle stabilization time constant, recoil impulse curve, and optic shake falloff.
  • QA criteria: legibility on bright floors and dark caves, color‑blind checks, frame pacing of pulsing/expansion, and zero retention after reloads.

15) Case Studies — Bringing It Together

Holo Rescue Dot. A low‑profile holographic with a 3 MOA dot and 40 MOA ring. Diegetic reticle brightens on ADS; HUD adds a faint recoil return cue. Battery fail reveals etched cross. Laser sits low‑left with a converged zero at 15 m. In smoke, reticle auto‑ramps gently and adds a one‑pixel outline.

LPVO Patrol Glass. 1–6× optic with a horseshoe‑dot at 1× and a BDC ladder at 6× tuned to the carbine’s zero. Magnification ring has chunky knurling; a throw lever nests to avoid snagging. Reticle authored as SDF to stay crisp. HUD drops entirely in simulation mode; in competitive, it adds a subtle lead tick when target velocity is high and perk is active.

Smart Sight (Foam/Net Tool). On‑glass shows nozzle spread or net canopy. World HUD anchors a predicted footprint decal that respects slope. Battery low triggers a slow amber band; failure drops to etched center mark. Opponents see only a soft lens iris and nozzle posture—no wall‑hack boxes.

Design reticles like you design hands: for bodies under stress. When diegetic optics, disciplined HUD, and honest calibration agree, players trust the sight picture. That trust is the quiet superpower that makes aiming feel inevitable—and your weapons, believable.