Why a 270×138 Sprite Sheet Should Not Simply Be Split into 4×2

The reused AI cover illustrates character poses. It is not the 270×138 sample or an exact representation of the grid calculated here.

Knowing that a sheet has four columns and two rows does not guarantee that dividing the whole image into eight equal rectangles is correct. Outer borders and internal gaps can make the evenly divided dimensions different from the actual frame canvas.

The public Sprite Animation Frame Tool guide describes grid and fixed-size splitting. The numbers below are a manual layout model, not detection results or evidence that every origin and spacing option exists in the current interface.

State the layout assumptions first

• Four columns and two rows.
• Each frame canvas is 64 by 64 pixels.
• All four outside borders are four pixels wide.
• Every horizontal and vertical internal gap is two pixels.
• Dimensions are actual pixels, with no export scaling.
• The confirmed layout is a regular grid, without rotated packing.

A 64-pixel frame canvas does not require the visible character outline to fill all 64 pixels. Transparent space may belong to the canvas, so visible-object width is not automatically the frame width in the equation.

Calculate the expected complete dimensions

Width is 2×4 + 4×64 + 3×2 = 270 pixels. Height is 2×4 + 2×64 + 1×2 = 138 pixels. Four columns have three internal horizontal gaps, while two rows have one internal vertical gap. The outside borders are separate terms.

Simply dividing 270 by four gives 67.5, and dividing 138 by two gives 69. Those results conflict with the known 64×64 frame canvas. That is a reason to inspect layout assumptions, not to stretch the artwork to 67.5×69.

Calculate cell origins and stride

Using coordinates starting at zero, column origins are 4, 70, 136, and 202. Row origins are 4 and 70. The stride between origins is 64 + 2 = 66, rather than 64. The general origin calculation is outer margin + cell index × (frame size + internal gap).

Check the final column: 202 + 64 = 266, leaving four pixels before the complete width of 270. The final row ends at 70 + 64 = 134, leaving four before 138. These sums identify boundaries, not the index of the final included pixel.

Use the offset pattern as a clue

If every output has a similar displacement, inspect the starting margin first. If displacement grows across columns or rows, check whether the stride omitted the gap. These are clues within the stated regular-grid model, not a unique diagnosis for irregular AI artwork.

Inspect the first, a middle, and the final frame before checking every output. Making only the first crop look right does not address accumulating error in the rest of the sheet.

Do not force unsupported parameters into an even split

Establish how the current interface represents margins, origins, or gaps. An operation that only divides the complete image evenly should not be assumed to skip this example's spacing automatically. Prepare a suitable source copy or choose a confirmed workflow that can express the layout, then inspect the real outputs.

Do not keep applying these equations to irregular, rotated, or tightly packed regions. Identify the input structure and retain its real coordinate information when needed. The broader sprite-sheet splitting guide covers the remaining workflow.

If crops are correct but transparent timed positions remain, use the empty-cell versus intentional-blank-frame guide. Correct spatial layout and the intended playback sequence are separate acceptance checks.