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sprite-segment-3x3grid

sprite-segment-3x3grid

github.com/unity-technologiesCreative & media1.2k3.5k installsUpdated 1d ago
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About sprite-segment-3x3grid

This Unity skill analyzes Sprite textures by dividing them into a 3×3 grid and comparing each cell with the center cell’s majority color. Its configurable match threshold supports sprite documentation, testing, and asset analysis.

Key features

  1. 01Divide textures into a 3×3 grid
  2. 02Find the center cell’s majority color
  3. 03Compare surrounding cells against a threshold
  4. 04Output a text grid

Use cases

  1. 01Document Sprite color patterns
  2. 02Check structure in automated tests
  3. 03Investigate differences in Sprite appearance
  4. 04Create searchable asset metadata

Install

Copy the command and run it in a terminal.

$npx skills add https://github.com/unity-technologies/skills --skill sprite-segment-3x3grid

After installing, type/sprite-segment-3x3gridin Claude Code to confirm it loaded.

Bundled filesscripts/SpriteGridAnalysis.cs

Details

From the project README

Sprite Color Grid Analysis

Purpose

This skill analyzes Sprite textures by segmenting them into a 3x3 grid and outputting a text representation based on color matching with the center cell.

Parameters

Match Threshold

The match threshold determines what percentage of pixels in a non-center cell must match the center's majority color for that cell to be considered a "match" (.).

ThresholdDescriptionUse Case
50%At least half the cell's pixels match center colorLenient matching for sprites with mixed regions
75%At least three-quarters match center colorModerate matching for mostly solid regions
90%Nearly all pixels must match center colorStrict matching for very uniform sprites

Default: 75%

Algorithm

  1. Segment the Sprite: Divide the Sprite's texture region into a 3x3 grid (9 cells total)
  2. Identify Center Color: Calculate the majority (most frequent) color in the center cell (position [1,1])
  3. Compare Each Cell: For each of the 8 surrounding cells, calculate what percentage of pixels match the center's majority color. If the percentage meets or exceeds the match threshold, the cell is a match (.); otherwise it is not (X)
  4. Generate Output: Create a text representation using the legend below

Output Legend

SymbolMeaning
XCell does NOT meet the match threshold (insufficient pixels match center color)
.Cell MEETS the match threshold (enough pixels match center color)
*The center cell itself (always position [1,1] in the grid)

Output Format

The output is a single line with three groups of three characters, separated by /. Each group represents one row of the grid.

Order: Top to Bottom rows, Left to Right within each row.

Format: [TopRow] / [MiddleRow] / [BottomRow]

Each row contains 3 characters separated by spaces: [Left] [Center] [Right]

Grid Position Mapping
Grid Layout:        Output Order:
[0,0] [1,0] [2,0]   1  2  3   -> First group
[0,1] [1,1] [2,1]   4  5  6   -> Second group (5 is always *)
[0,2] [1,2] [2,2]   7  8  9   -> Third group
Examples

Example 1: Center matches top-left and bottom-right only

. X X / X * X / X X .

Grid interpretation:

.  X  X
X  *  X
X  X  .

Example 2: Center matches all surrounding cells

. . . / . * . / . . .

Example 3: Center matches none of the surrounding cells

X X X / X * X / X X X

Example 4: Center matches bottom row only

X X X / X * X / . . .

Implementation Guidance

Calculating Center's Majority Color

For the center cell:

  1. Sample all pixels within the cell's bounds
  2. Group pixels by color (consider using a color tolerance threshold for similar colors)
  3. The majority color is the color with the highest pixel count
  4. For tie-breaking, use the first color encountered
Matching Non-Center Cells

For each of the 8 surrounding cells:

  1. Count the total number of pixels in the cell
  2. Count how many pixels match the center's majority color (using color tolerance)
  3. Calculate the match percentage: matchingPixels / totalPixels
  4. If match percentage >= threshold, cell is a match (.); otherwise (X)
Color Tolerance

When comparing pixel colors:

  • Consider using a tolerance threshold (e.g., RGB distance < 10) for "matching"
  • Alternatively, for sprites with limited palettes, exact matching may be appropriate
  • Account for alpha channel if relevant to the use case
Sprite Bounds

Use the Sprite's rect property to determine the pixel region to analyze:

  • sprite.rect.x, sprite.rect.y for the origin
  • sprite.rect.width, sprite.rect.height for dimensions
  • Divide width and height by 3 to get cell dimensions

References

Code Template: "scripts/SpriteGridAnalysis.cs"

Use Cases

  • Documentation: Describe sprite patterns in a compact text format
  • Testing: Verify expected sprite structure in automated tests
  • Analysis: Quickly identify sprites with similar color distributions
  • Debugging: Understand why sprites look different than expected
  • Asset Cataloging: Generate searchable metadata for sprite assets

Notes

  • This analysis works best with sprites that have distinct color regions
  • For sprites with gradients or many colors, consider increasing color tolerance
  • The Y-axis is flipped from Unity's texture coordinates to produce top-to-bottom output
  • Transparent pixels can be treated as a distinct "color" or ignored based on use case

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