Draw a sprite

The order matters more than the technique. Detail added before the form is right just makes the wrongness harder to see and more expensive to fix.

Procedure

1. Look before you draw

preflight, then sprite_info. You need the real layer names, frame count and palette. Do not assume them — a wrong layer name means drawing into the user's finished art.

If aseprite:concept produced a PixelSpec, it is the plan: its landmarks and bounding boxes are where the shapes go, its palette mapping is which colour each mass gets, its deviations are what you leave out. When a reference layer exists (reference op="list"), you are drawing over it — the steps below are the same, and step 3 gains a comparison.

Then read the subject rules for what you are drawing — the table in skill://studio under Subject rules names them. A hand, a face, a horse, an isometric crate or a waterfall each has its own file with size budgets and ```grid templates. A template is a starting point you transcribe with draw op grid, mapping each legend role onto the sprite's palette; adapt it to the pose rather than inventing the shape from nothing.

2. Block in the silhouette

One flat colour, no detail. Target the base layer. Everything in one draw call.

For anything up to about 32×32, write it as a grid: one character per pixel, so you see the whole silhouette while you write it instead of finding out afterwards what a stack of ellipses and rects added up to.

draw layer="base" label="block in slime" ops=[
  { kind:"grid", x:8, y:10, legend:{ "O":"#5f574f" }, rows:[
    "....OOOO....",
    "..OOOOOOOO..",
    ".OOOOOOOOOO.",
    "OOOOOOOOOOOO",
    "OOOOOOOOOOOO",
    ".OOOOOOOOOO." ] }
]

Every row must be the same width, . is transparent, and transparent cells erase what is under them (transparent:"skip" to stamp over existing art instead). Bigger sprites: one grid per body part or per layer, each at its own x/y — long rows of identical characters are where a model miscounts, and a ragged row is refused with its row number rather than silently shifted.

Shapes are still the right tool for big regular forms — a sky gradient, a floor, a 40-pixel circle:

draw layer="base" label="block in knight" ops=[
  { kind:"ellipse", rect:{x:12,y:4,width:8,height:8}, color:"#5f574f", fill:"#5f574f" },
  { kind:"rect",    rect:{x:11,y:12,width:10,height:10}, color:"#5f574f", fill:"#5f574f" },
  …
]

Batch aggressively. One call is one undo step for the user; forty calls are forty. See rules://03-silhouette-and-form.

3. Check the silhouette immediately

look op="preview"

Ask yourself the only question that matters here: is it recognisable as one flat shape? If not, fix it now. Shading a bad silhouette is wasted work.

Watch for: symmetry that reads as a statue, tangents where an arm fuses into the torso, limbs all the same thickness.

With a reference, preview blends the half-transparent reference into the art — use look op="compare" instead: reference left, art right. Name the three to five largest mismatches (silhouette, proportion, pose, where the colour masses sit), fix only those in one draw call, compare again. Stop when what is left is a deviation the PixelSpec lists. This loop repeats after materials (step 4) and after shading (step 5): the reference is a check on every stage, not only the first.

4. Separate the materials

Replace regions of the blockout with each material's base colour — skin, metal, leather, cloth. Still flat. Still one draw call.

5. Shade

See aseprite:shade. One shadow step, look, one light step, look. Stop there unless the sprite is 32px+ and genuinely needs more.

6. Outline

Pick one style from rules://04-outlines-and-edges and apply it consistently. Selective outlining — outside only — is usually right. transform op outline does the mechanical part: side="outside" grows the shape by a pixel, side="inside" recolours its edge and keeps the size; diagonals=true fills the corner pixels for square corners, off leaves them cut and softer. Hand-place where you want it broken.

6b. Text, if the art has words

draw op kind text lays out a string from a bitmap font and draws it in the same batch as everything else. Pass measureOnly: true with only text ops first to get the ink bounds back without touching the sprite — that is how you centre a label or size a panel around it before committing to a position. See TOOLS.md for the font format.

7. Verify precisely

look op="ascii"

The text grid is where you catch the pixel one row too low and the line run of 3 in a sequence of 2s. A preview cannot show you those.

To fix what it shows, edit the grid itself: look op="ascii" layer="base" rulers=false region=… returns bare rows plus origin; change the cells that are wrong and send the rows back as draw kind grid at that origin, with the legend look gave you. Only the region you send is touched. A glyph is a palette index and means the same colour in every region you read.

8. Validate and report

validate

Fix every error. Report warnings you chose not to fix, with the reason.

Batching rules

• Ops run in array order, so paint fills before outlines and outlines before highlights.
• Leave paletteLock on. When the result says a colour moved with ΔE > 12, the palette has no colour for what you asked — say so rather than turning the lock off.
• Use label to describe the intent; it becomes the user's undo entry.

Related

rules://00-core-principles, rules://02-shading-and-light, rules://03-silhouette-and-form, rules://04-outlines-and-edges, rules://10-lines-and-curves, rules://11-clusters-and-noise, and the subject files listed in skill://studio under Subject rules.