Bone tool

Draw, parent and pose the bones of a rig, directly on the canvas.

The Bone tool (J) works on a Bone layer: the container that holds a rig's bones and their bindings. With several rigs, it works on the rig of the selected layer: the selected Bone layer, or the Bone layer the selected layer sits in. With no such layer selected, it works on the rig whose bone is picked, otherwise on the first Bone layer. Clicking with the Bone tool active and no Bone layer yet creates one for you, but only in Edit mode; in Animate mode, with no Bone layer, the tool has nothing to do.

Drawing a bone#

In Edit mode, drag from empty canvas to draw a root bone with no parent. Drag from an existing bone's body instead, and the new bone is parented to it, starting where you clicked: this is how you build a chain, one drag per link. A drag shorter than a small minimum length does not become a bone; it just deselects instead.

Switch Bone Type to Static before you place one, and a click, not a drag, drops a round handle bone instead. Static bones are IK goals and control points: they can be positioned and keyframed, but they do not deform anything themselves.

Selecting and parenting#

Click a bone's body to select it. Shift adds more to the selection, but only among bones of the same kind: you cannot multi-select a Stretched bone together with a Static one.

Turn on Reparent, then drag a bone onto a new parent to move it in the hierarchy. Celas Studio refuses a drop that would make a bone its own ancestor, and rebases the bone's stored angle keyframes so its current pose does not jump when the parent changes.

Tool options#

Bone Type: Static, Move and Reparent are mutually exclusive: turning one on switches the other two off. Snap is independent and can be combined with any of them; holding Ctrl or Cmd also snaps a bone endpoint transiently while you draw, even with Snap itself turned off.

Endpoint and stretch handles#

A selected bone's start and end grips appear while you hold Alt, or while Move is on. Drag one to change the bone's length and angle: its children counter-rotate so they hold their pose rather than visibly snapping.

In Animate mode a small square handle appears a short way from the tip of the selected bone; drag it to stretch the bone without changing its rotation.

Rest pose vs. Animate mode#

Edit mode poses the rig's rest skeleton: moving or rotating a bone there changes its base pose, ripples down to every child, and affects any frame that has no keyframe of its own. Animate mode poses one specific frame: dragging a bone's body there rotates it around its parent joint, and the result is stamped as a keyframe on release when that channel's auto-key is armed.

Right-click deselects every bone. The one exception is a key mark on the selected bone's motion path, where right-click opens that key's menu. There is no bone context menu and no double-click behaviour.

The bone's motion path#

In Animate mode the selected bone shows its motion path, in the bone's own colour: the handle's track for a Static bone, the tip's track for any other bone. Square marks are the bone's keys. Drag a key to re-pose the bone at that frame, or drag a dot between keys to add a key there first. A Static bone's keys have bezier handles that bend its path. On a turning bone the handles set how it eases in and out of the key instead.

The path includes the motion an action gives the bone. Inside Action Mode, a Static bone's path bent this way is followed when the action plays.

Right-click a key, or press and hold it on a tablet, for Reset Bezier and Smooth Bezier (Static bones only), Easing, Interval and Delete Keyframe. A clicked key is highlighted, and Delete removes it without touching the bone. See Motion path.