Painting hints
A hint is a fact about your artwork that the artwork itself does not state. Painting one is not retouching the result — you are not pushing pixels toward a look — you are adding something the tool then has to satisfy along with everything else.
Why they exist
The tool works from the silhouette and the line work, and between them those settle most of a sprite. What they cannot settle are the cases where two genuinely different surfaces produce the same picture:
- An arm across a body, and a fold in one continuous surface, have the same outline.
- A hard-cut edge, and a surface curving away out of sight, have the same outline.
- A cylinder and a dome have the same outline.
- A dome, a dish and a flat patch of texture can all be drawn with the same marks.
- Painted shading and an inked fold are both dark marks.
Guessing at these is how a generator produces confidently wrong output. Rather than guess, the tool asks — and a hint is the answer.
Painting them
Select a hint tool and drag over the artwork. The stroke shows in that tool's colour, matching its swatch in the toolbox.
- Erase with Alt-drag, or by dragging with the right mouse button.
- Undo with Ctrl+Z, redo with Ctrl+Shift+Z. One drag is one step, however many mouse events it arrived as. Undo covers painting only — settings have their values written beside them.
- Brush size is the Radius field in the options bar. Tools that draw along a line start at your artwork's measured line width; tools that fill a region start much larger.
- Hardness sits beside it, and controls how far the brush fades at its edge. Full hardness is still antialiased — the rim gets partial coverage rather than a stepped edge — so lower it only when you want a genuinely soft mask, which is usually on high-resolution artwork. It is remembered between sessions and is not part of a project or a preset.
- Strokes are clipped to the artwork. Painting outside the silhouette has no effect, so you can be loose at the edges.
- See what you painted with Always show hints in the options bar, and turn Onion skin down to compare a mask against the line beneath it.
Edit ▸ Clear all hints removes every layer at once, and is undoable.
Which layer to reach for
| The problem | The hint | How to paint it |
|---|---|---|
| Fold you can see has no effect | Add stroke B | Along the line |
| Crease where there is no fold | Remove stroke E | Over the offending marks |
| Hard edge looks rolled | Cut outline C | On the outline itself |
| Flat panel bulges | Flatten F | Fill the panel |
| Limb domes instead of tubing | Tube axis A | Along the limb's length |
| Limb blends into what is behind it | In front D | Fill the nearer part |
| Eye or boss reads flat | Convex area O | Fill the domed shape |
| Crater or dent reads flat | Concave area I | Fill the hollow |
| Surface nothing else describes | Trust methods T | Fill the region |
Domes and dishes
Convex area and Concave area are for a shape that has an edge but no silhouette — a glassy eye in a scaled face, a rivet, a crater. The sprite's outline says nothing about such a shape, and the strokes drawn around it read as a fold, which is why an eye tends to come out flat with a pinched ring around it.
Fill the shape and its edge becomes the rim of a surface of its own: edge-on at the rim, facing you in the middle for convex, falling away for concave. The two are the same hint with the direction reversed.
They pair well with Remove stroke. Erase the eye's outline first, then fill it — otherwise the stroke and the rim are both describing the same edge, and the stroke's version is a fold.
Telling whether a hint took effect
Three hints have a precondition, and when it is unmet they do nothing at all. Rather than leave you guessing, the application says so after the stroke:
- Cut outline must touch outline pixels. Painted inside the shape it has nothing to act on: "this cut touches no outline pixels".
- Tube axis must reach the outline, which depends on Tube axis reach being wide enough for the limb: "the axis never reaches the outline — raise the reach".
- Trust methods scopes methods that have a weight. With every method at zero there is nothing to scope: "no method has weight yet".
If you painted something and nothing changed and no message appeared, the likeliest explanation is that the hint agreed with what the tool had already concluded.
Hints are per sprite
A hint addresses particular pixels. Carried to a different sprite, or to a different frame of the same animation, those pixels are somewhere else — so hints do not travel:
- Projects save hints, because a project is one sprite and its work.
- Presets do not, because a preset is settings meant for many sprites.
- Frames each keep their own. See Frames and animation.
Getting masks out of Photoshop or Aseprite instead
Painting a mask that matches your artwork exactly, with this tool's brush, is slower and less precise than doing it in the
program you drew the artwork in. So you do not have to: import a .psd or an .aseprite file and map its layers directly
onto hint layers. Name a layer for the hint it feeds and the mapping is suggested for you. See
Importing.
You can also write your painted hints out as PNGs — File ▸ Export hint layers… — which is the way to see exactly what the solver was given, and to hand the work to somebody else without a project file.