The mask is the hidden structure of a wobble animation. White or strongly painted areas receive more displacement, lightly painted areas receive less, and untouched pixels stay fixed. A preset controls the rhythm, but the mask decides which material appears flexible and whether it remains attached to the picture.
Natural results come from three zones: a stable anchor, a responsive center, and a gradual transition between them. The goal is not perfect tracing. It is a believable distribution of motion strength that matches how hair, fabric, cheeks, ears, food, or a soft product would bend in the real world.
Find the anchor before touching the brush
Ask what carries the weight. Hair attaches to the scalp, an ear to the head, fabric to a seam, pudding to a plate, and a hanging charm to a ring. Leave that connection unpainted or use only the lightest strength there. The eye needs one stable reference to interpret the rest as softness.
Trace the intended motion with your cursor before painting. Mark the free end, flexible middle, attachment zone, and nearby background. Screenshot brief: place four arrows on one image to label those areas, then show the finished mask beside it. This planning pass prevents the common mistake of painting the most obvious outline at full strength and discovering a visible cut later.
Brush-size comparison: small, medium, and large
Brush size changes more than speed. It changes how continuous the selected material feels. The Studio range runs from 8 to 140. On an image around 1000–1200 pixels, a small 16–28 brush is useful for hair tips, thin ribbons, fingers, or careful erasing. It gives control but can create streaks and holes when used to fill a large shape.
A medium 45–70 brush works for cheeks, ears, sleeves, small plush bodies, and most boundary passes. It covers enough area to avoid patchwork while staying clear of the background. A large 90–130 brush is useful for pudding, a round mascot, loose cloth, or the center of a broad soft object. Keep a smaller eraser ready to restore the anchor.
| Brush size | Best for | Typical risk | Correction |
|---|---|---|---|
| 16–28 | Hair tips and narrow details | Striped or incomplete fill | Overlap strokes and zoom in |
| 45–70 | Cheeks, ears, sleeves, boundaries | Painting across the anchor | Erase the connection zone |
| 90–130 | Large soft centers | Background overspill | Fill center first, refine later |
Feather the edge with strength, not blur
Purupuru Maker does not need a separate Feather command. Brush strength provides the transition. Paint the flexible center at 70–90%, then lower strength to 40–55% for an overlapping boundary pass. Near the anchor, use 15–30% only where a small amount of movement helps the shape bend smoothly.
Avoid drawing three hard rings. Let passes overlap with loose, irregular edges that follow the material. Hair can use narrow tapered strokes; pudding can use a broad center and a soft crescent near the plate; fabric can follow folds while leaving the seam quiet. Screenshot brief: show the same mask as a solid hard blob and as a three-strength gradient, then freeze both previews at maximum displacement.
Video tutorial in words: a complete natural-mask pass
Record the final mask screenshot with the strength control visible. That makes the tutorial reproducible; an unlabeled red overlay does not tell a reader how the boundary was built.
00:00–00:20 — inspect and choose the material
Open the image, fit it to the canvas, and say what should move in one sentence: “Only the hair below the ear sways.” Identify the scalp as anchor and the tips as the free end. Do not paint while deciding; twenty seconds of inspection saves several erase passes.
00:20–00:55 — block the responsive center
Choose brush size 52 and strength 70% as a neutral starting point. Paint the middle of the flexible shape with overlapping strokes. Leave a clear gap at the anchor and stop just inside the outer silhouette so the first pass cannot bend background pixels.
00:55–01:25 — add the transition
Lower strength to 40%, reduce brush size to about 32, and bridge the center toward the outline. Add a lighter 20% pass near the attachment where needed. Switch to Erase and clean any background, text, eye, or rigid edge caught by the brush.
01:25–02:00 — preview, diagnose, and refine
Start with Sway at speed 0.8, amplitude 10, and damping 0.60 for hair, or Jelly at speed 1.0, amplitude 16, and damping 0.45 for a round object. Watch two cycles. Correct the mask before raising intensity: fill holes, soften a hard seam, and restore the anchor.
Four mask failures and their visual symptoms
A mask that is too small creates a floating patch or a double outline. Expand it beyond the visible feature and taper the new edge. A full-strength boundary creates tearing; repaint the transition with lower strength. Background overspill makes walls, captions, or neighboring objects bend; erase it while viewing maximum displacement.
Painting the anchor at full strength makes the subject slide away from its support. Restore the attachment and increase damping if it still feels loose. A mask with internal holes creates ripples or stationary spots inside moving material; use a larger brush to unify the center. Screenshot brief: present all four failures at the same preset and amplitude so the mask, rather than motion settings, is the only changing variable.
Advanced masks for more than one moving detail
You can paint disconnected regions in one mask. A mascot might move both ears, or a portrait might sway two hair tips. Keep each region graded and make sure the shared preset makes physical sense for both. If one detail needs slow Sway and another needs fast Quake, create two exports; the current single mask uses one motion system at a time.
For a pseudo-layered result, give the primary feature higher strength and the secondary feature lower strength. Try 75% on the near ear and 40% on the far ear to imply depth. Preview at small size and export a GIF plus WebM comparison: GIF edge result [需要实测], WebM edge result [需要实测]. Judge silhouette stability rather than file size alone.
Paint material behavior, not just an outline. A stable anchor, a unified center, and a low-strength transition produce a smoother wobble than a tiny hard selection or extreme amplitude ever can.