Chapter 2 – Dust saliva spores slime material rules

Chapter 2: Dust, Saliva, Spores, Slime — Material Rules

Created by Sarah Choi (prompt writer using ChatGPT)

Dust, Saliva, Spores, Slime: Material Rules for Creature Sound × VFX × Motion

Secondary materials—dust clouds, saliva strings, spore puffs, slime trails—are the “truth serum” of creature design. They are tiny, but they reveal physics. They tell the audience what is dry or wet, brittle or elastic, light or heavy, clean or rotten, natural or engineered. Most importantly, they are cross‑discipline glue: the same material rule should govern what you see (VFX), what you hear (audio texture), and how the body moves (animation timing and contact logic). When these three agree, the creature becomes believable. When they fight, players feel the mismatch immediately, even if they can’t explain why.

This article is a practical set of material rules for concept artists who want to design these secondary effects on purpose—both in early concepting (to sharpen ideation and pitch clarity) and in production (to reduce downstream ambiguity for VFX, animation, tech art, and audio). We’ll focus on how dust, saliva, spores, and slime attach to the four creature sound channels: vocal, footfalls, breath, and fluids.

The core idea: materials are “behavior multipliers,” not decoration

A dust puff is not just a cool effect. It’s a statement about dryness, surface granularity, impact energy, and air displacement. A saliva string is not just gross; it’s viscosity, adhesion, jaw timing, and mouth geometry. Spores aren’t just a cloud; they imply an ecology, a risk model, and a cadence. Slime is not just wet—slime is a whole locomotion and readability system.

If you treat these as decoration, you’ll get random, inconsistent notes. If you treat them as rules, you get a creature that can be animated and mixed consistently across dozens of states, surfaces, and camera distances.

The triangle you’re serving: Sound × VFX × Motion must share the same physics

A useful mental checklist is: one material, three proofs.

Motion proof: what does the creature do physically that causes the material event (compression, shear, snap, squeeze, shake)?
VFX proof: what do we see as a result (puff, spray, string, droplet, haze, smear, residue)?
Sound proof: what do we hear (dry burst, wet tack, airy hiss, gritty crumble, viscous pull)?

When you add a material beat, design all three proofs—even if you only draw one. Your callouts can carry the rest.

The four channels: where secondary materials show up

Secondary materials connect to the creature through four channels:

Vocal: mouth, throat, resonators; saliva, mucus, breath vapor, spore cough.
Footfalls: contact points, surface response; dust, mud, slime suction, debris scatter.
Breath: intake/exhale; vapor, condensation, spores, mist, bubbling.
Fluids: deliberate secretion or injury; slime coats, venom drips, spore shedding, drool.

A good creature picks a primary channel to own the material identity and uses the other channels as supporting evidence. If everything is equally wet, equally dusty, equally spore‑y all the time, you lose readability.

Material rule framework: the “4 V’s” that keep you consistent

For dust, saliva, spores, and slime, you can build reliable rules using four variables:

Volume: how much appears per event (trace, small, medium, huge).
Viscosity / cohesion: how much it clumps, strings, and resists breaking.
Volatility: how easily it becomes airborne and how long it lingers.
Visibility: how readable it is at gameplay distance; how much it competes with silhouette.

In concepting, decide these quickly as a style choice. In production, lock them as constraints so every state stays on‑model.

DUST: rules for dry worlds, old bodies, and heavy impacts

Dust is the cleanest secondary material because it’s readable and usually rating‑safe. Dust communicates dryness, age, and impact energy. It also acts like a “motion highlighter,” making contact points and silhouettes easier to read.

Dust + footfalls: contact logic is everything

Dust responds to impact and shear.

Impact puff is driven by weight and speed; it peaks immediately on contact.
Shear plume is driven by lateral slide (skids, turns, claw drags) and trails behind motion.

Motion rule: if the creature’s gait is heavy, you need a clear compression moment—heel/paw/hoof contact, knee bend, mass settle—so dust has a cause.

VFX rule: dust should have a readable shape language. Heavy creatures make low, mushrooming puffs; fast light creatures make thin, sharp streaks; skids create fan-shaped sprays.

Sound rule: dust pairs with broadband “thoomph” and gritty grit layers—short and dry. The louder the grit, the closer you are to the camera. From far away, dust should read visually while audio simplifies.

Dust + breath: age, ash, and dryness cues

Dust in breath is a tone choice. It can imply ash lungs, desert filtration, or a creature that’s half stone.

Motion rule: breath dust appears on exhale and often after exertion.

VFX rule: keep it subtle unless the creature class is explicitly “ash/ruin.” A light haze that catches light can be enough.

Sound rule: dusty breath is a dry hiss and throat rasp. It should never sound wet.

Dust + vocal: brittle resonance

Dusty vocal reads as hollow, brittle, ancient.

Design hook: cracked plates, porous stone skin, dry membranes.

Rule: vocal events can shed micro‑dust only on big calls, not every chirp, or it becomes comical.

SALIVA: rules for predation, intimacy, and the grossness dial

Saliva is powerful because it instantly signals mouth intent: hunger, threat, and proximity. It also risks tone drift. The key is to treat saliva as a controlled instrument, not a constant coat.

Saliva variables: string, drip, spray, smear

Saliva has four main visual behaviors:

String: elastic bridge between surfaces (jaw to jaw, tongue to teeth).
Drip: gravity-driven drops that detach and fall.
Spray: atomized mist from shakes, snarls, impacts.
Smear: residue on surfaces after contact (bite marks, drool trails).

Each behavior implies viscosity and motion timing.

Saliva + vocal: mouth rhythm as metronome

Saliva is most believable when it is tied to jaw timing.

Motion rule: strings appear on slow opens and closes; sprays appear on fast snaps or head shakes.

VFX rule: strings should stretch before they break. If they pop instantly, it reads like water, not saliva.

Sound rule: strings pair with subtle tacky “pull” textures; sprays pair with short wet bursts; drips are tiny but can be emphasized in quiet horror beats.

Saliva + breath: wet exhale and proximity

Breath + saliva becomes visible when the creature is close or exerting.

Motion rule: heavy panting creates rhythmic wetness. One wet inhale/exhale loop can define a threat state better than any roar.

VFX rule: avoid constant mist unless you want a horror mood. Consider “only during rage” or “only when injured.”

Sound rule: wet breath is about texture, not volume. It’s the layer that makes the audience uncomfortable—use intentionally.

Saliva + footfalls: the “evidence trail” trick

Saliva can leave traces on the ground during a chase (droplets on impacts).

Rule: this should be rare and state-specific (enraged, wounded, feeding), otherwise it becomes messy and confusing.

SPORES: rules for ecology, hazard readability, and cadence control

Spores are a design gift because they connect creature, environment, and mechanics. They can also become visual noise if you don’t set boundaries.

Spores are not smoke: they have a biological logic

Spores should behave like living particulate:

They may clump or stream from vents.
They may pulse (release cycles).
They may settle as visible residue.

Decide whether your spores are:

Defensive (spike release on threat),
Reproductive (periodic shedding),
Symbiotic (fungus living on creature), or
Weaponized (engineered cloud).

Spores + breath: the cadence engine

The cleanest spore system is breath‑driven.

Motion rule: spores release on exhale, cough, or snort. Tie it to ribcage motion so anim has a clear trigger.

VFX rule: spore clouds should have a readable pulse and decay. The player should see when a hazard window begins and ends.

Sound rule: spore breath is airy and particulate—soft bursts with a granular edge. Avoid making it sound wet unless spores are in mucus.

Spores + vocal: threat punctuation without gore

A roar that triggers a spore ring is a strong “boss read.”

Rule: keep vocal articulation clean; let the spores carry the weirdness. If both vocal and spores are chaotic, readability collapses.

Spores + footfalls: environment storytelling

Footfalls can kick up spore dust from infected ground.

Rule: decide if spores belong to the creature or the biome. If it’s biome-driven, the creature should not be the only spore source—nearby props and surfaces should also react.

SLIME: rules for viscosity, locomotion, and surface ownership

Slime is the most design‑demanding material because it affects everything: silhouette, shader, collision feel, VFX cadence, and sound texture. If you commit to slime, you must give it rules.

Slime is a system with three states: coat, strand, puddle

Coat: a glossy layer that changes roughness and highlights.
Strand: stretched slime bridges between surfaces.
Puddle/residue: deposits left behind, which become gameplay readability concerns.

Decide which state is primary. A creature that is always puddling slime changes level readability and performance budgets.

Slime + footfalls: suction, peel, and smear

Slime footfalls are about adhesion.

Motion rule: slime steps need a peel moment. The foot sticks, then releases. If the animation doesn’t show that delay, the sound will feel fake.

VFX rule: a slime footfall is not just a splash. It’s a smear + strand + suction pop. Even a tiny strand between foot and ground sells viscosity.

Sound rule: slime footfalls are dominated by tacky pops and low wet smears, not sharp impacts. The heavier the creature, the more low-frequency “squelch” you’ll hear.

Slime + breath: internal wetness and horror dial

Slime breath can imply internal mucus systems.

Rule: keep it state‑based. Let idle be quieter, threat be wetter, injured be the wettest. That ladder gives audio and VFX a structure.

Slime + vocal: resonance through wet membranes

Wet throats change the vocal signature.

Design hook: visible membranes, gular sacs, mouth corners that glisten.

Motion rule: vocalization should deform soft tissue visibly—throat pulses, mouth flex—so the wet audio has a visual match.

Building a “material budget” so creatures don’t become noise

In games, secondary materials compete with gameplay readability. You need a budget.

A practical budget system is:

Primary material (the signature): dust or slime or spores or saliva.
Secondary material (support): one subtle supporting material.
Tertiary material (rare): only in special states (rage, injured, ultimate).

For example:

Desert titan: primary = dust, secondary = grit chips, tertiary = ash breath.
Amphibious stalker: primary = saliva strings, secondary = wet breath, tertiary = slime trail when enraged.
Fungus guardian: primary = spores, secondary = dusty footfalls, tertiary = mucous spore cough when injured.

This keeps your creature readable and gives production clear limits.

Cadence rules: how often materials should “speak”

Secondary materials are most effective when they have rhythm.

Dust cadence is usually step-driven (every 1–3 steps, or only on heavy landings).
Saliva cadence is mouth-driven (on jaw opens, on snarls, on shakes).
Spore cadence is cycle-driven (pulses, coughs, breath releases).
Slime cadence is adhesion-driven (peel moments, drags, residue events).

In concepting, you can describe this simply: “spores pulse every exhale” or “slime strands appear only on turns and climbs.” In production, you can refine it into per-state rules.

Surface rules: materials must change with biome and ground type

One of the biggest production mismatches is when a creature’s material behavior is identical on every surface.

Dust should reduce on wet ground and increase on dry grit.
Saliva reads differently in cold air (condensation) versus humid caves.
Spores behave differently indoors (confined haze) versus outdoors (wind shear).
Slime on metal is slick and loud; slime on moss is damp and quiet.

Even if your concept art doesn’t show every surface, your callouts can declare the intention: “dust only on dry surfaces,” “slime suction strongest on porous stone,” and so on.

Practical callouts concept artists can add

These are short, high-value notes that make your sheet production-friendly:

Material map: mark always-present zones (mouth corners, vents, feet pads) versus state-based zones.
Trigger list: “dust on landings,” “saliva strings on slow mouth opens,” “spores on exhale,” “slime strands on peel.”
Knob settings: low/medium/high for grossness, linger time, and visibility.
Forbidden behaviors: “no constant spore haze,” “no puddle trails except ultimate,” “no wet audio layers in calm state.”

These notes stop downstream teams from guessing.

Concepting-side workflow: add material rules without slowing ideation

When you’re exploring silhouettes and forms, you can still integrate material rules quickly:

Pick one signature material that differentiates the creature.
Decide the primary trigger (step, breath, mouth, injury).
Add one anatomical hook that makes the trigger believable (valve, sac, pad, plate).
Sketch one moment panel: the clearest single frame where the material speaks.

This keeps your exploration fast but grounded.

Production-side workflow: turn material rules into implementation clarity

In production, your material rules become part of the package:

State sheet: idle/move/turn/attack/hit/death with notes on which material behaviors are active.
Attachment points: exact locations where VFX emits (mouth corners, vents, joints, heel plates).
Interaction notes: what materials do on different surfaces.
Performance notes: what can be simplified at distance (reduce drool strings, convert spores to a soft card, reduce slime strands).
Accessibility notes: which layers are optional or reducible (high-frequency spore hiss, constant skitter ticks, heavy wet mouth loops).

This helps audio and VFX scale detail across camera distance and hardware.

A closing rule of thumb: make materials teach the player

The best secondary materials do not merely look cool; they teach. Dust teaches weight and surface. Saliva teaches intent and proximity. Spores teach risk and timing. Slime teaches adhesion and pathing. When you design material rules as part of Sound × VFX × Motion, you build a creature the player can understand at a glance—and a creature the team can ship consistently.

If you want one sentence to carry forward into every creature sheet: “Choose one signature material, tie it to one reliable trigger, and make motion, VFX, and sound all prove the same physics.”