Using the Lasso and Transform Tool

What the lasso is for

The lasso is the most capable tool in the editor, and the one most likely to be overlooked. It lets you draw a freehand loop around part of a frame and then treat everything inside that loop as a single object — move it, resize it, rotate it, copy it to another frame, or delete it.

For animation specifically, that makes it a shortcut around an enormous amount of redrawing. An arm that needs to swing can be rotated rather than redrawn. A character that needs to drift across the canvas can be moved. A head that needs to tilt two degrees per frame can be duplicated and nudged. None of this replaces hand-drawn animation, but it removes the mechanical parts of it.

Making a selection

Drag a loop around the region you want. The path you draw is treated as a closed polygon, so you do not need to return exactly to where you started — the gap between the ends is closed for you. Everything the polygon contains becomes the selection, and a bounding box appears around it.

Whether a point counts as inside is decided geometrically, not by proximity, which means concave loops behave the way you would expect. You can draw a horseshoe around a character's arm and the torso sitting in the opening of the horseshoe will not be selected. Pressing Escape clears the selection without changing anything.

What happens to strokes on the boundary

This is the behaviour worth understanding properly, because it is what separates the lasso from a simple object picker. When a stroke crosses the edge of your loop, it is not selected whole and it is not left out — it is cut at the point where it crosses. The part inside the loop joins the selection; the part outside stays where it is.

The consequence is that the lasso selects regions of your drawing rather than whole strokes. You can lasso the top half of a single long pen stroke, drag it upward, and the stroke will visibly separate at the line you drew. That is extremely useful when you want it — selecting a leg from a figure drawn in one continuous line, for example — and surprising if you were expecting the whole stroke to come along.

The transform handles

Once a selection exists, five handles appear around it. Each is a small target area around its point, so you do not have to hit a single pixel.

Scaling from the centre

Corner handles scale around the centre of the bounding box, not around the opposite corner. This is worth saying plainly because it is the opposite of what most image editors do, and it changes how you use the tool.

Dragging the bottom-right handle outward does not anchor the top-left corner and grow away from it; it grows the selection in all directions at once, with the middle staying exactly where it was. In practice this is usually what you want in animation, because the thing you care about — a head, a hand, a ball — stays centred on the position you already placed it at, and you do not have to move it back after resizing.

The two axes respond independently: how far you drag horizontally sets the width, and how far you drag vertically sets the height. That means you can squash and stretch a selection directly, which makes the lasso a practical tool for the deformation described in squash and stretch — lasso a ball, drag a corner mostly sideways, and you have a squashed ball that is still centred where the original was.

Rotating

The rotate handle sits on a short stem above the middle of the top edge, clear of the corner handles so the two are not easy to confuse. Dragging it turns the selection around the centre of the bounding box, following the angle from the centre to your pointer.

One detail makes this much more usable than it sounds: the rotation is always applied to the drawing as it was at the moment you grabbed the handle, not to the result of the previous frame of the drag. You can swing a selection back and forth for as long as you like while deciding on an angle, and the drawing will be exactly as sharp at the end as it was at the start. There is no accumulated degradation, so experimenting costs nothing.

Rotation is the single biggest time saver for limb movement. A forearm rotated a few degrees per frame around the elbow is a credible arm swing for a fraction of the drawing effort — and because rotation around a point produces a curved path, it gets you the arc almost for free.

Copying, pasting, and deleting

With a selection active:

• Ctrl C — copy the selection.
• Ctrl V — paste it. The copy lands offset by twenty pixels from the original, so it is immediately visible and draggable rather than hidden exactly on top of what you copied.
• Delete or Backspace — delete the selection, including any partial strokes the loop cut.

A paste always goes onto the currently active layer. This matters more than it first appears: if you copy a character from a character layer, switch to the background layer, and paste, the character is now part of your background and will no longer move independently. Check which layer is active before pasting — see working with layers for how to keep a project organised enough that this is obvious.

Using it to animate

A few workflows that are much faster with the lasso than without it:

• Limb swings. Lasso the forearm, rotate it a few degrees, duplicate the frame, rotate again. Five frames of arm movement without drawing a new arm.
• Squash and stretch. Lasso the whole subject and scale it wider and shorter for an impact frame, taller and narrower for a fast travel frame.
• Repositioning a whole figure. Lasso everything, drag it across the canvas, and you have a frame of travel with no redrawing at all.
• Fixing drift. If a character has slowly wandered up the canvas across a sequence, lasso the offending frames one at a time and nudge them back into alignment.
• Breaking a drawing into parts. Because boundary strokes are cut, you can lasso a head off a single-stroke figure and paste it onto its own layer, converting a flat drawing into a layered one.
• Building a cycle. Copy a pose from frame 1 and paste it onto the last frame so a walk cycle loops perfectly rather than approximately.

1. 1
   Pick the lasso tool

   Press L, or choose the lasso from the toolbar. On desktop it is in the vertical rail on the left; on mobile it is in the dock near the bottom of the screen.
2. 2
   Draw a loop around what you want

   Drag a freehand outline around the part of the drawing you want to affect. You do not have to close the loop precisely — the ends are joined for you when you release.
3. 3
   Check the bounding box

   On release, a rectangle appears around everything that was captured, with four corner handles and a rotate handle on a short stem above the top edge. If it enclosed the wrong things, press Escape and draw again.
4. 4
   Drag inside the box to move it

   Dragging anywhere inside the selection repositions it. This is the most common operation and needs no handle.
5. 5
   Drag a corner handle to scale

   Corner handles resize the selection around the centre of the bounding box, so the middle stays put and both sides grow or shrink together. Width and height respond independently to how far you drag horizontally and vertically.
6. 6
   Drag the rotate handle to turn it

   The handle above the top edge rotates the selection around the centre of the box. The rotation is always computed from the drawing as it was when you started the gesture, so a long adjustment does not accumulate errors.
7. 7
   Commit or cancel

   Click outside the selection to commit the result, or press Escape to clear the selection. Ctrl+Z undoes a committed transform like any other edit.

Common mistakes

• Expecting whole strokes. Strokes crossing the loop are cut at the crossing. If you wanted all of a stroke, your loop needed to be outside all of it.
• Expecting corner-anchored scaling. Scaling works from the centre of the box. Drag a corner and the whole selection grows outward in every direction.
• Pasting onto the wrong layer. Pastes land on the active layer, not the layer the original came from. Check before you paste.
• Rotating repeatedly in small steps. One drag is better than five, and the tool is built for it — hold the handle and keep adjusting until the angle is right.
• Animating everything with transforms. A character moved and rotated but never redrawn reads as a paper cut-out. Use the lasso for the mechanical parts and draw the parts that carry the performance.
• Losing track of a selection. If a drag is doing something unexpected, press Escape to clear the selection and start again.

Where to go next

If you have not set up a project yet, start with getting started with FrameAnim. Because pastes depend on which layer is active, working with layers is the natural companion to this guide.

For animation that uses transforms heavily, the walk cycle is full of rotating limbs, and squash and stretch is almost entirely a scaling exercise. The full tutorial index is at all tutorials.