Reference · Nomenclature

Glossary

The working vocabulary of top-down pixel art. Every lesson uses these words to mean exactly this.

Anti-aliasing · Autotile · Banding · Cast shadow · Cluster · Contact shadow · Dithering · Front face · Hue shifting · Indexed palette · Isometric · Jaggies · Negative space · Noise · Oblique 3/4 · Outline · Pillow shading · Ramp · Readability · Selective outlining · Silhouette · Sprite · Tile · Tileset · Top face · Transition tile · Value

Anti-aliasing AA: Placing an intermediate colour along an edge to soften the step between two others — “using a colour in between to fill some of those pixels to create the illusion of a softer transition.” In pixel art it is placed by hand, one pixel at a time, and used sparingly: at 16×16 an over-antialiased sprite turns to mush. Pedro Medeiros, Pixel Grimoire #5 — Anti-Alias and Banding
Autotile bitmask tiling: A set of tiles authored so the engine can pick the right variant automatically from which neighbours are filled. Godot's TileMap terrain system does this. Requires a disciplined naming and layout scheme up front.
Banding: When two colour bands run parallel along the same diagonal for too long, producing an unintended stripe that reads as a hard ridge. The classic beginner artefact of shading “one step in from the outline”. Pedro Medeiros, Pixel Grimoire #5
Cast shadow: The shadow an object throws across the ground away from the light. Long directional cast shadows are banned in this project — they collide with whatever tile is placed next door. See contact shadow.
Cluster: A deliberately shaped group of same-coloured pixels. Clusters, not individual pixels, are the real unit of pixel art: they “create textures, reduce visual noise, and enhance details.” Good work has few, well-shaped clusters; noisy work has many tiny ones. Pedro Medeiros, Pixel Grimoire #2 — Cluster sketching and painting
Contact shadow: The small dark smudge where an object meets the ground. It is what stops a sprite from looking like it is hovering. Short, hugging the base, offset about a pixel down-and-right under a top-left sun. Clause 3 of the contract.
Dithering: Alternating two colours in a pattern (checkerboard, 50%, or graded) to fake an intermediate value or a texture. Cheap at large sizes; expensive at 16×16, where a dither pattern eats most of a tile and quickly reads as noise.
Front face: The near vertical surface of an object — the side pointed at the camera. Rendered uncompressed, because height is never compressed. Sits below the top face and is one to two values darker.
Hue shifting: Rotating the hue as well as the value along a ramp: shadows shift cooler and less saturated, highlights shift warmer. Straight value ramps read as muddy; hue-shifted ramps read as lit. Raymond Schlitter, SLYNYRD — Pixelblog 1: Color Palettes
Indexed palette: An image mode where each pixel stores an index into a fixed colour table rather than an RGB value. Aseprite's Indexed mode. Lets you recolour an entire sprite set by editing the table — the fastest route to day/night or corruption variants. Aseprite Docs — Color Mode
Isometric: A projection where all three axes are equally foreshortened, usually drawn on a 2:1 pixel slope. Not what this project uses. Included so the word doesn't get used loosely: what we are drawing is oblique 3/4.
Jaggies: Unintentional corners in a line — a run of 3 pixels next to a run of 1 next to a run of 4. They “usually appear when making natural hand movements”. Fix by making each run's length step evenly (4-3-2-1, or all 2s). Pedro Medeiros, Pixel Art Fundamentals
Negative space: The unworked area around and inside a shape. In tiling, deliberately empty ground between textured clusters — “a busy texture next to another busy texture may exhaust the eyes… negative space is your friend.” Raymond Schlitter, SLYNYRD — Pixelblog 20
Noise: Scattered single pixels of contrasting value with no shape logic. Reads as dirt on the screen rather than detail. The most common way a 16×16 tile fails.
Oblique 3/4 top-down 3/4, “RPG view”: The projection this project uses. Width and height render 1:1; ground depth is compressed — here, to two-thirds. You see the top of things and their front. The view of Zelda: A Link to the Past, Stardew Valley, Hyper Light Drifter. See the contract.
Outline: A dark border separating a sprite from what is behind it. A full outline reads as clean and cartoon-like; no outline reads as painterly and can get lost against busy ground. See selective outlining.
Pillow shading: Shading in concentric rings inward from the silhouette, as if the light came from directly in front of the viewer. The result looks inflated and flat. The symptom of not having committed to a light direction — which is why the contract fixes one.
Ramp colour ramp: An ordered run of colours from dark to light used to shade one material. “A specific range of colours that work well together, arranged according to brightness.” A palette is a set of ramps that share colours at their ends. Raymond Schlitter, SLYNYRD — Pixelblog 1
Readability: Whether the sprite can be identified at 1× zoom, in motion, against real game background. The only measure that matters. Judge every sprite at 1× before calling it done.
Selective outlining: Outlining only where the sprite needs separating from the background — dark outline on the lit side, none or a light one on the shaded side. Reads more three-dimensional than a uniform black keyline and costs fewer pixels.
Silhouette: The sprite's outer shape, filled solid. If it isn't identifiable as pure black on white, no amount of internal shading will save it. The first thing to fix and the first thing to check.
Sprite: A single drawn image placed in the world — a character, a prop, one frame of an animation. In Aseprite the word also means the document: “a sequence of frames and a stack of layers.” Aseprite Docs
Tile: One cell of the terrain grid. 16 × 16 px in this project. Designed to sit next to copies of itself without a visible seam — the giveaway line where two tiles meet.
Tileset: The full sheet of tiles a map is assembled from: base terrains, their transitions, and edge variants.
Top face: The upward-pointing surface of an object. Rendered at two-thirds of the object's real depth, because depth is compressed. Always the lightest surface, because it points at the sky.
Transition tile: A tile that blends one terrain into another — dust into cracked earth, dirt into boardwalk. Built by interleaving the two textures' cluster densities rather than by drawing a hard boundary line. Raymond Schlitter, SLYNYRD — Pixelblog 20
Value: How light or dark a colour is, independent of hue and saturation. Value carries form; hue carries mood. It is the load-bearing property in pixel art: a sprite with correct values and wrong hues still reads, and the reverse never does.