Chapter 3: Constructing Forms

Created by Sarah Choi (prompt writer using ChatGPT)

Constructing Forms (Boxes, Cylinders, Planes) & Foreshortening

Construction is the bridge between lively gesture and believable, shippable character art. By reducing anatomy and costume to primitive solids—boxes, cylinders, and planes—you gain control over form, proportion, perspective, and composition under any camera. This article shows concept artists on both the concepting and production sides how to use construction to keep poses readable, volumes turnable, and packages build‑ready.

1) Why Construction Matters

Stylization thrives on truth. If the underlying solids are clear, stylized proportions and ornate costumes feel intentional instead of arbitrary. Construction:

  • Stabilizes proportion across views and variants.
  • Prevents perspective drift by forcing consistent vanishing behavior.
  • Exposes rig risks early (cape bite, belt pinch, shoulder compression).
  • Improves composition by clarifying overlaps, silhouettes, and focal paths.

2) Primitive Solids: Your Working Alphabet

2.1 Boxes (Direction & Measure)

Boxes carry orientation information. A pelvis box tipped forward tells the spine how to arc; a rib cage box canted left sells breathing weight. Boxes make measurements visible—edge lengths, face angles, and parallelism.

  • Use cases: Rib cage, pelvis, footwear, pouches, scabbards, hard armor plates, backpacks.
  • Practice: Draw boxes with different tilts (pitch/yaw/roll) and label facing planes (top/front/side). Add a small arrow for the dominant normal to track orientation across a pose.

2.2 Cylinders (Flow & Hinge)

Cylinders describe limbs and soft armor sleeves. Their ellipses communicate turn, taper, and foreshortening.

  • Use cases: Upper/lower arms, thighs/calves, necks, hoses, tassels; round pauldrons and bracers.
  • Practice: Ladder drills—stacked cylinders pointing toward a common vanishing zone. Include taper (wider toward camera), and notch the cylinder for bony landmarks (ulna, tibia) to keep anatomy honest.

2.3 Planes (Readability & Material Breaks)

Planes capture how light and material change. A cheek plane break explains a shadow; a gauntlet’s chamfer plane becomes a crisp specular highlight.

  • Use cases: Faces (Loomis planes), armor bevels, boot caps, cape folds simplified as angular planes for clarity.
  • Practice: Take a complex prop (bracer) and reduce to 5–7 planes. Paint each plane a single value; rotate it and keep the value logic intact.

3) Building the Figure from Solids

Step 1: Gesture & Line of Action. One decisive curve (C/S/I) sets intention. Place head/rib cage/pelvis along the curve.

Step 2: Block the Masses. Use a rib cage box (front plane visible), a pelvis box (top plane often visible), and a cranial ball + side plane. Lock tilt/lean/twist relationships.

Step 3: Limb Vectors → Cylinders. From mass corners, shoot vectors for upper limbs, then sleeve with tapered cylinders. Cut ellipses at joints to show orientation.

Step 4: Hands/Feet as Wedges. Wedge primitives determine stance and grip clarity. Add finger/boot boxes later.

Step 5: Costume Volumes. Float armor and cloth as thicker boxes/cylinders around the body. Leave air gaps where mobility demands (armpit, groin, knee pit).

Step 6: Plane Simplification. Carve faces into plane groups that describe light flow and material breaks.

This six‑step pass creates a turnable mannequin that survives camera changes and supports fine design.

4) Foreshortening: Truths That Make Depth Read

Foreshortening isn’t a special effect; it’s consistent construction under perspective. Anchor on these rules:

  • Ellipses tell the tale. The closer a circle rotates toward edge‑on, the ellipse narrows and its minor axis aligns to the vanishing direction. Keep all limb ellipses coherently oriented.
  • Taper toward camera. Forms broaden toward the viewer; far segments compress. Overlap decisively so nearer forms break the contour of farther ones.
  • Priority of forms. The biggest foreground plane wins. Don’t let thin lines compete with major overlaps; widen and darken foreground edges.
  • Measure in head units. Use head counts to estimate depth length (e.g., forearm ≈ 1–1.25 heads). Mark checkpoints along the axis to avoid “accordion limbs.”
  • Shadow logic. Cast shadows fall across compressed surfaces; they should also foreshorten. Use them to stage depth and protect silhouette.

5) Perspective Without the Panic

You don’t need a perfect grid to be convincing—you need consistent convergence.

  • Vanishing families. Pick a rough 2‑ or 3‑point setup for the pose. Assign boxes and cylinders to those families and keep them honest.
  • Sight straight, build crooked. Sight the overall angle of the LoA; let boxes/cylinders snap to believable vanishing directions, then nudge for clarity.
  • Depth staging. Foreground (thick line, high contrast), midground (moderate), background (thin, low contrast). Costumes should follow the same staging: high‑contrast near the face/weapon, calmer elsewhere.

6) Composition from Construction

Construction reveals negative spaces (between arm and torso; between cape and leg). Shape these deliberately to frame the focal path (face → hands/weapon → weight foot). Use plane changes to lead the eye—bright plane on face, medium on torso, dark on legs. Arrange box axes to create rhythm (e.g., pelvis tilt contra to rib cage tilt), which adds life without clutter.

7) From Concepting to Production: What Changes

Concepting side. Move fast with primitives—solve pose, proportion, and big design with boxes/cylinders/planes. Deliver gesture thumbnails, construction overlays, and painterly turnarounds that keep volumes turnable.

Production side. Translate to orthos with ruler ticks, joint centers, skirt profiles; callouts with plane breaks for material changes, and pose sheets that show start/impact silhouettes for rig and VFX. Construction lines become vendor language: bevel widths, panel depths, and strap routing.

8) Common Failure Modes (and Fixes)

  • Noodle limbs. No cylinder taper or ellipse alignment. Fix: Add tapered cylinders with clear ellipses; mark bony landmarks.
  • Mushy armor. No plane definition. Fix: Bevel into explicit planes; assign value steps.
  • Perspective spaghetti. Box faces ignore the same vanishing set. Fix: Choose vanishing families; check parallel edges.
  • Cape eats action. Cloth volume not boxed early. Fix: Block cape as a thick wedge; add slits; echo LoA.
  • Foreshortening collapse. Equal widths along depth. Fix: Overlap aggressively; widen foreground edges; compress far segments.

9) Drills for Mastery

  • Box Gym (10 min): 20 boxes with random pitch/yaw/roll; mark axes; shade two planes only.
  • Cylinder Ladder (10 min): 5 cylinders stepping toward camera; align ellipse minors; add taper; ink overlaps.
  • Plane Carve (15 min): Take a face or bracer; reduce to 7 planes; rotate 45° and keep plane value logic.
  • Foreshortening Chain (15 min): Arm from shoulder to fist at extreme reach; checkpoint every 1/4 head; force overlaps.
  • Negative Space Audit (10 min): Fill interior gaps with white; remove tangents; open triangles at elbows/knees.

Bundle these as a daily 1‑hour construction circuit.

10) Camera Contexts & Construction Notes

  • FPP: Hands/arms need crisp plane breaks; glove wedge must not occlude sights. Ellipses on sleeves should align with camera FOV.
  • TPP: Backpack/cape boxes must clear the over‑shoulder camera; weapon cylinder should not align tangent to torso silhouette.
  • Isometric: Exaggerate box/plane clarity; merge micro‑planes into larger masses for readability.
  • Cinematics: Increase plane granularity on faces and hero props; keep gameplay model consistent with a simplified plane set.

11) Collaboration Map

Design: Receives construction thumbs to validate kit ergonomics and holster reach.

Animation/Tech Anim: Receives pose sheets with cylinder axes and skirt profiles; returns joint limits and cloth layers.

Character/Tech Art: Receives callouts with plane breaks and bevel specs; returns topology and shader hooks.

VFX/Audio: Receives emitter socket planes and action arcs; returns palette pressure and timing beats.

UI/UX: Receives icon silhouettes derived from clean construction; returns HUD occlusion constraints.

Cinematics/Marketing: Receives hero frames with refined planes; returns close‑up fidelity targets.

12) Packaging Tips (Make Construction Visible)

  • Include a construction overlay page in decision packs—blue pencils over clean lines.
  • Add a plane key (1–7) with material notes (matte cloth, brushed metal, clear coat).
  • Mark ellipse headings at elbows/knees/wrists/ankles on orthos; tech anim can sanity‑check ranges fast.
  • Keep naming/versioning consistent: CH_Name_Construct_v### and log what changed (tilt, taper, plane count).

13) Final Thought

Construction and foreshortening are not afterthoughts—they are the silent architecture that makes your characters read, move, and ship. Speak the language of boxes, cylinders, and planes early; let ellipses and overlaps carry depth; and package those truths so every collaborator—from animation to tech art—builds on the same solid foundation.