Character: overview & layout

The Character tool — subtitled "Mixamo-compatible · 65 bones" in the Studio — is where you pose and keyframe a humanoid skeleton and export the result as an animation clip or a GLB that plays in a stock THREE.GLTFLoader. It runs entirely in the browser, like the rest of ThreeJS Assets Studio. Animating is free: posing, keying, sequencing, the clip library, and clip JSON export cost nothing. Building a character with the Character Creator is free to use too, but taking that character out — its GLB, or its editable source bundle — requires owning the character product. This article maps the interface; the tasks live in the articles that follow.

The 65-bone Mixamo rig#

The editor drives one fixed skeleton: a 65-bone rig with Mixamo bone names, every bone prefixed mixamorig: (for example mixamorig:Hips, mixamorig:LeftArm). The count breaks down as:

• Spine and head — 7 bones (Hips, Spine, Spine1, Spine2, Neck, Head, HeadTop_End).
• Arms — 24 bones per side (shoulder, arm, forearm, hand, plus five fingers of four bones each), 48 total.
• Legs — 5 bones per side (UpLeg, Leg, Foot, ToeBase, Toe_End), 10 total.

Hips is the root. The rig is frozen: the bone list, names, and rest offsets never change, which is what lets any clip you author play back on any Mixamo-rigged character you later import. The character starts in a T-Pose, and a Wave sample clip ships alongside it so there is always something to scrub.

Your poses and keys belong to the 65-bone control rig. When you import your own character, the Studio matches its Mixamo bones to those controls. You continue animating the control rig, and the imported model follows it.

A character you build with the Character Creator is a normal subject of this same rig: it binds to all 65 Mixamo bones, so every clip in the library and everything you author yourself plays on it with no retargeting step.

The four panels#

The editor is a three-column layout with a timeline docked across the bottom. Every region is a resizable panel:

• Bone Hierarchy (left) — the skeleton as a collapsible tree. Click a bone to select it; the selection syncs to the viewport and the sidebar. Expand/collapse-all controls sit above the tree.
• Viewport (center) — the lit 3D stage with the skeleton overlay drawn in emerald, a ground grid, three-point lighting, and a soft ground shadow. Draggable IK handles appear here when you turn them on.
• Sidebar (right) — a four-tab strip, one group of controls on screen at a time:
• Pose — selected bone, presets and keys: rotation (and, for Hips, position) fields, the preset poses, and the keying buttons.
• Rig — IK targets and additive layers.
• Clips — clip library, clips, root motion, sequence.
• Char — pick a character or import your own .glb, then shape it.
• Timeline (bottom) — the transport bar (play/pause/stop, loop, speed, duration, FPS, time readout) plus a tab strip that switches between the dope sheet and the curve editor.

The Char tab is roster-first: its Character panel is the cast list for the project, with each character's own actions on its row and an always-present Add a Character button underneath. Bringing your own model in is the panel's second tab, Import. The rest of the tab holds the shaping sections — Style & proportions, Colours & palette, Face & expression, Speech, Render, and Export & source — covered in the Character Creator.

A small badge in the top-right of the viewport mirrors the current selection: it reads green for a bone and switches to a purple "IK target" label when an IK handle is selected.

Selecting and framing in the viewport#

You can select a bone two ways: click its row in the Bone Hierarchy, or click the joint directly in the viewport. Joint picking is screen-space — every bone head is projected and tested against a fixed pixel radius, so finger joints are as easy to hit as the hips at any zoom. Hovering a joint shows its mixamorig: name as a tooltip.

Camera control is standard orbit:

• Left-drag — orbit
• Right-drag — pan
• Wheel — zoom
• F — frame the character (fit to view, keeping the current view direction)
• 1–6 — jump to Front / Back / Left / Right / Three-quarter / Top camera bookmarks

Press M to toggle viewport shading (studio lighting vs a matcap preview), and Esc to clear the selection.

Render toggles and framing#

The Render section, in the Char tab, holds six viewport flags and three framing buttons. None of them changes the character itself and none of them reaches the export — they only change what you see:

Four of these — shadows, grid, skeleton overlay, and turntable — are the same flags the toolbar's View cluster owns, so the panel and the buttons always agree.

Three framing buttons sit under the toggles: Reset view returns the camera to the default three-quarter view, Frame head moves in for a head-and-shoulders view, and Frame body fits the whole character in the viewport.

Where to go next#

• Posing & IK — FK gizmos, two-bone and full-body IK, mirroring, and preset poses.
• Keyframes, dope sheet & curves — auto-key, the dope sheet, easing curves, and onion skins.
• Clips, sequences & layers — managing clips, crossfaded sequences, and additive layers.
• The Character Creator — build a character in the Char tab instead of importing one.
• Importing your own character — bring a Mixamo-rigged GLB.
• Exporting animations — clip JSON, GLB, and batch export.