Chapter 1: Joint Ranges, Collision & Cloth Risk Zones

Created by Sarah Choi (prompt writer using ChatGPT)

Joint Ranges, Collision & Cloth Risk Zones

1. Why Joint Ranges and Cloth Risk Zones Matter for Costume Concept Artists

When you design costumes for games, you’re not just dressing a still illustration—you’re dressing a moving, breathing, fighting, emoting character that exists inside a real‑time engine.

Every bend of the knee, twist of the spine, sword swing, and emote places demands on the costume. Long coats, capes, skirts, belts, chains, tassels, holsters, and props all have to survive that motion without turning into a clipping, jittering mess.

This is where joint ranges, collision, and cloth risk zones come in. They sit at the intersection of:

  • Metrics – how far joints actually move, what animation ranges are expected.
  • Motion – how the character runs, jumps, attacks, casts spells, or plays an instrument.
  • Story – what the costume needs to communicate about role, faction, rank, and personality.
  • Interaction – how the character’s costume interacts with weapons, props, environment, other characters, UI, and even audio.

This article is written equally for:

  • Concept‑side costume artists, who explore and define visual direction and narrative.
  • Production‑side costume artists, who refine, standardize, and package designs for downstream teams.

We’ll frame joint ranges and cloth risk zones as key tools for partnering with Character Art, Rigging, Tech Art, Animation, Narrative, UI, and Audio, so your designs are not only beautiful but also buildable, animatable, and expressive.

2. The Core Idea: Costumes Are Moving Systems, Not Static Paintings

A costume is a system of moving parts:

  • Rigid elements that follow bones: armor plates, hard accessories, weapon holsters.
  • Semi‑rigid elements: leather skirts, padded jackets, stiff collars.
  • Flexible cloth: skirts, capes, scarves, sashes.
  • Dangling bits: tassels, chains, ribbons, feathers, jewelry.

All of these move relative to a skeleton with limited joint ranges:

  • Hips, knees, ankles.
  • Spine, shoulders, elbows, wrists.
  • Neck, jaw, fingers.

If your design ignores how far those joints move, where meshes collide, or where cloth tends to misbehave, you end up handing Character Art, Rigging, and Tech Art a problem to fix, not a vision to build.

Your job as a costume concept artist is not to solve every technical issue, but to design with motion in mind:

  • Place shapes where the skeleton can support them.
  • Use cloth where motion and collision are manageable.
  • Highlight story and role in ways that survive animation.

3. Metrics: Understanding Joint Ranges and “Extreme” Poses

The first step is to understand the metrics of your character rigs: how far they actually move.

3.1 What Are Joint Ranges?

Joint ranges are the angles and distances a character’s joints can reach in animation. For example:

  • How far can the shoulder raise and rotate forward/backward?
  • How deep can the character crouch?
  • How far can the spine twist?
  • How high can the knee lift in a run or kick?

Animation and Rigging usually define these ranges based on:

  • The game’s animations (combat, traversal, emotes).
  • The rig’s technical limits (number of bones, deformation quality, performance budgets).

3.2 “Comfort Pose” vs. “Stress Pose”

When designing costumes, think in terms of two categories:

  • Comfort poses – idle, light walk, casual gestures.
  • Stress poses – full sprint, big attack, deep crouch, extreme twist, knockback, dramatic emote.

Many designs look fine in comfort poses but break badly in stress poses:

  • Skirts lock the knees in a deep crouch.
  • Armor plates punch through the chest or back on big swings.
  • Capes completely engulf the character in mid‑jump.

As a concept artist, you don’t need precise angle values, but you should internalize: “What are the most extreme poses this character will perform?” and test your design against them visually.

3.3 Building a Joint Range Reference

Production‑side costume artists can help by:

  • Maintaining a joint range sheet: a set of poses that show max flex/extension at each major joint.
  • Sharing this sheet with concept‑side artists as a reference lineup.

Concept‑side artists can then:

  • Place simple silhouettes or rough costume blockouts over these reference poses.
  • Immediately spot problem zones and adjust designs early.

This is a simple but powerful way to connect metrics with design.

4. Collision: Where Costumes Fight the Body and Props

Collision is where the geometry of the costume intersects with the body, with itself, or with props and environment.

4.1 Common Collision Zones

Some areas are nearly always risky:

  • Shoulders and armpits – armor and capes crowd joints with large motion.
  • Hips and thighs – skirts, tabs, belts, scabbards, and holsters intersect legs.
  • Neck and collar – high collars, scarves, and hoods clash with jaw and shoulder motion.
  • Lower back and butt – long coats, backpacks, and capes collide in crouches or rolls.

When you place heavy or rigid elements in these zones, you’re asking Rigging and Tech Art to fight physics and geometry in every animation.

4.2 Collision with Weapons and Props

Weapons and props introduce additional collision risks:

  • Back‑mounted swords cutting through capes.
  • Side holsters colliding with long coats or hip plates.
  • Shields intersecting shoulder armor or helmets.

Partner with Character Art, Rigging, and Animation by:

  • Checking how weapons are drawn and stowed in existing animations.
  • Designing scabbards, holsters, and straps so they clear arcs of motion.

4.3 Cloth vs. Rigid Collision

Cloth and rigid parts behave differently:

  • Rigid parts must be carefully placed so they don’t intersect body or weapons at all.
  • Cloth parts can be simulated, but heavy intersection or layering will still cause sim jitter, popping, or unnatural behavior.

As a concept artist, you can:

  • Use smaller, more controlled cloth elements in high‑collision zones.
  • Reserve big, dramatic cloth (capes, trains) for areas where movement arcs are more predictable.

5. Cloth Risk Zones: Where Cloth Creates the Most Trouble

Cloth risk zones are parts of the character where cloth is likely to cause problems for animation, collision, or readability.

5.1 High‑Risk Areas

Typical cloth risk zones include:

  • Knees and thighs – long skirts and coats can tangle or lock motion.
  • Feet and ankles – trailing fabric and long trains cause tripping and clipping.
  • Shoulders and upper arms – cape attachments, mantles, large epaulets.
  • Hands and wrists – long sleeves, tassels, and jewelry that collide with weapons.

5.2 Risk Factors

Risk increases with:

  • Length – the farther cloth extends beyond the body, the more it intersects.
  • Layering – multiple cloth layers colliding with each other and rigid armor.
  • Complex silhouettes – asymmetrical drapes, overlapping trains, extreme volume.

Concept‑side artists can mark these zones as:

  • “High risk – Sim candidate, check with Tech Art”.
  • “Medium risk – May need rig support or design simplification”.

Production‑side artists can refine those notes into:

  • Cloth sim maps and mobility overlays in the final costume package.

5.3 Cloth Risk vs. Story and Role

Sometimes story demands high‑risk cloth: a ceremonial gown, a royal cape, a mystical veil.

In those cases, you partner with Narrative, Animation, and Tech Art to answer:

  • Is this costume reserved for cutscenes only (less extreme motion)?
  • Can animations be adjusted to honor the garment (less acrobatics, more gravitas)?
  • Can Tech Art budget extra simulation and rigging to support it?

Not every costume has to be combat‑ready. Some are intentionally constrained, but that decision should be conscious and cross‑disciplinary.

6. Partnering with Character Art: Buildable Forms and Clear Layers

Character Art is your closest partner in turning costume concepts into in‑game models.

6.1 Clear Layering and Separation

Character Art needs to know:

  • Which parts are separate meshes (cape, shoulder armor, belts).
  • Which parts are fused (stitched panels, integrated padding).
  • How garments stack: undershirt → vest → harness → cape.

As a concept artist, you can:

  • Provide layer diagrams: simple exploded views or labeled turnarounds.
  • Use color coding or line conventions to show under vs. over layers.

This directly affects where collision and cloth risk happens: clear layering helps Character Art and Tech Art decide where to cut meshes, where to sim, and where to keep things rigid.

6.2 Respecting the Base Body and Proportions

Joint ranges and collision zones are partly determined by the base body:

  • Overly thick armor around joints can prevent good deformations.
  • Massive shoulder stacks can hide head and neck motion.

Collaborate by:

  • Reviewing base body orthos with Character Art.
  • Designing costumes that respect exposed joint zones: elbows, knees, armpits.

Production‑side artists often take the lead on aligning costume orthos to final base bodies and rigs.

7. Partnering with Rigging: Mobility Maps and Attachment Points

Rigging defines how the skeleton deforms the mesh—and how extra bones and constraints support cloth and props.

7.1 Mobility Maps

A mobility map is a simple overlay where you mark:

  • Joints with high motion: shoulders, hips, knees, elbows.
  • Areas with expected stretching: sides of the torso, inner thighs.
  • Protected regions where you want minimal deformation (chest emblem, rigid armor).

As a concept artist, a mobility map can be as simple as coloring zones on an ortho and annotating them. Rigging can then:

  • Plan extra support bones or correctives where needed.
  • Warn you if some costume pieces are unrealistic for the intended motion.

7.2 Attachment and Anchor Points

Rigging also cares about where things attach:

  • Cape anchors on the collar or under shoulder plates.
  • Weapon holsters anchored to belts or shoulder rigs.
  • Jewelry or tassels anchored to helmets or armor plates.

Concept‑side artists can:

  • Mark attachment points clearly on callout sheets.
  • Keep attachments close to bones (collarbones, hips, spine) for stable motion.

Production‑side artists can turn this into a clean anchor map for rigging, minimizing guesswork.

8. Partnering with Tech Art: Cloth Sim Budgets and Risk Management

Tech Art sits at the nexus of art and engineering, responsible for cloth simulation, physics, and performance.

8.1 Sim Budget: Not Everything Can Be Cloth

Every project has limits:

  • Number of cloth sim components per character.
  • Complexity of each cloth mesh.
  • Overall performance budget.

As a costume concept artist, this means you must decide:

  • Which cloth areas are must‑have sim (hero cape, iconic skirt).
  • Which can be rigged or skinned with simple bones.
  • Which should be fake cloth (painted or rigid approximations).

Partner with Tech Art by:

  • Labeling cloth elements as “Sim priority,” “Secondary,” or “Non‑sim” in your concepts.
  • Accepting simplification when Tech Art flags high‑risk zones.

8.2 Cloth Risk Zones as Tech Art Conversations

When you identify cloth risk zones, bring Tech Art in early:

  • Ask: “Can we support this cape length with your sim system?”
  • Ask: “Would this layered skirt stack cause collision issues in your current setup?”

Production‑side artists often lead these conversations, turning them into clear visual documentation (cloth sim maps, collision notes) in the final costume package.

9. Partnering with Animation: Motion, Phrasing, and Attitude

Animation is where all your costume decisions are stress‑tested.

9.1 Designing for Signature Moves

Every character has signature moves:

  • A tank’s shield bash.
  • A rogue’s backflip or dash.
  • A mage’s staff windup.

Costumes need to support these moves, not fight them.

Work with Animation by:

  • Reviewing key animations or animatic blocks.
  • Testing your designs in pose thumbnails: draw the costume over a few critical frames.

Ask:

  • Does the costume accentuate the motion (cape flare, sleeve direction)?
  • Does anything obscure important silhouettes or FX (huge cape hiding spell VFX)?

9.2 Emotes, Narrative Beats, and Everyday Motion

Not all motion is combat:

  • Emotes (laugh, sit, dance).
  • Narrative moments (hugging, kneeling, comforting another character).

Cloth and accessories should look intentional in these moments:

  • Skirts should still allow sitting without excessive clipping.
  • Cloaks should drape convincingly when the character leans.

Concept‑side artists can sketch emote poses with costume to check for awkwardness. Production‑side artists can work with Animation to identify problem emotes and adjust designs.

10. Partnering with Narrative: Story-Driven Risk and Restraint

Narrative defines who the character is and why their costume matters.

10.1 Story Justifies Design, Design Respects Story

Some narrative beats justify pushing into higher risk zones:

  • A ceremonial robe that restricts motion as a sign of status.
  • A battle‑worn cape that is iconic to the character’s legend.

In those cases:

  • Narrative can support animation changes (fewer flips, more grounded motion).
  • Art and Tech can justify allocating extra resources to make the costume behave.

10.2 Story as Constraint, Not Just Decoration

Narrative can also constrain risk:

  • A stealth character might be explicitly designed to avoid jangling chains or flapping cloth.
  • A disciplined military unit might standardize armor to avoid risky silhouettes.

As a costume concept artist, partner with Narrative to:

  • Decide where cloth and collision risk are part of the story.
  • Decide where practicality and discipline should limit design excess.

11. Partnering with UI: Readability Over Motion and Cloth Noise

UI cares about how the character reads in:

  • Portraits and character select screens.
  • Icons and ability cards.
  • Minimap or overhead markers.

11.1 Motion and Cloth vs. Readability

Big cloth and accessories can:

  • Obscure team colors or role markers.
  • Create noisy silhouettes in small thumbnails.

Work with UI by:

  • Ensuring key team/role colors are placed on stable parts of the body (chest, shoulders, helmet) that stay visible across poses.
  • Avoiding putting critical iconography on high‑risk cloth that flaps and twists.

11.2 Interaction with UI Elements

UI overlays might appear near or on the character:

  • Health bars above the head.
  • Status icons near shoulders.

Design costumes so they don’t compete for attention in those spaces:

  • Avoid extremely busy shapes or high contrast directly behind persistent UI.
  • Keep head and shoulder silhouettes clear and simple enough to silhouette well.

Production‑side artists often test costume read in UI mockups, adjusting value balance or detail density if needed.

12. Partnering with Audio: Where Cloth and Props Make Sound

It’s easy to forget Audio, but costumes can be an important part of a character’s soundscape:

  • Clinking armor.
  • Swishing cloth.
  • Rattling chains, beads, or charms.

12.1 Sound‑Supporting Design

If Audio plans to create cloth and gear sounds:

  • Make sure those elements are visually justified: belts, buckles, fabric types.
  • Place them where they will realistically move enough to trigger sound.

For example:

  • A character with many small charms on a belt will have audible movement—design that belt to be visible and active.

12.2 Avoiding Unintended Noise

For stealthy or quiet characters, Audio may want minimal noise:

  • Avoid excessive chains, jangling metal, or extremely stiff cloth.
  • Let the costume support the fantasy of moving silently.

Partnering with Audio is often as simple as:

  • Sharing concept sheets and noting where movement and sound are intended.
  • Listening to feedback on whether some elements should be toned down or emphasized.

13. Practical Habits for Costume Concept Artists

To make joint ranges, collision, and cloth risk zones part of your everyday design practice, build a few habits.

13.1 Always Test at Least One Stress Pose

For every serious costume design, sketch or block out at least one stress pose:

  • A deep crouch.
  • A strong attack.
  • A run or dash.

Check:

  • Do joints have enough room to move?
  • Does cloth tangle or obscure important elements?

13.2 Maintain a Personal “Risk Zone” Overlay

Create a transparent overlay for your mannequin showing:

  • High‑motion joints.
  • Typical collision and cloth risk zones.

Drop this overlay on top of your concepts to quickly spot design hot spots.

13.3 Use Color Coding for Risk and Sim Priority

On your callout sheets:

  • Mark high‑risk cloth in one color.
  • Mark sim candidates in another.
  • Mark rig‑only elements (no sim) in a third.

This visual language helps Character Art, Rigging, Tech Art, Animation, and even leads quickly see where attention is needed.

13.4 Keep Communication Lightweight but Regular

Instead of waiting until everything is polished, share early with partner disciplines:

  • A quick blockout pass with notes.
  • A mobility map sketch.
  • A cloth risk map.

Short, early conversations save much more time than late, heavy revisions.

14. From Isolated Paintings to Cross‑Discipline Costume Design

Joint ranges, collision, and cloth risk zones might sound like purely technical topics, but they are really about collaboration and respect:

  • Respect for what Character Art can reasonably build.
  • Respect for what Rigging and Tech Art can realistically simulate.
  • Respect for how Animation wants characters to move.
  • Respect for Narrative’s vision of who these characters are.
  • Respect for UI’s need for clarity.
  • Respect for Audio’s role in making costumes feel alive.

As a concept‑side costume artist, integrating joint range awareness and cloth risk mapping into your process turns your designs from “cool paintings” into credible, animatable characters.

As a production‑side costume artist, building clear documentation and visual overlays helps every downstream partner work with confidence, reducing rework and last‑minute panic.

When you treat metrics, motion, story, and interaction as partners in your design—not afterthoughts—you create costumes that carry their narrative weight, move beautifully, avoid technical disasters, and feel truly at home in the game world and the player’s hands.