Animated sprite normal maps

Normal maps give sprite surfaces a directional response to deferred point, spot and directional lights. They shape highlights and the shaded sides of a sprite; they do not add cast shadows or geometry. Room fill remains diffuse.

Add AnimatedNormalMap next to SpriteAnimator. Leave Source empty to use the animator's GUID-backed Aseprite asset, or assign another Aseprite file. List the normal layer names in Layers, then press Reload to preview changes. The component also reloads on scene start and re-enable. Save in Edit mode.

Keep normal layers hidden in Aseprite so they do not enter the albedo. Explicit normal selections include hidden layers. For each visible art layer, paint a matching normal layer on the same animation frames and canvas. Preserve tags, frame order and poses; include neutral normals for visible effects or props that should stay flat. The normal and diffuse atlases can be packed differently. Missing animation bindings use neutral normals.

Encode tangent-space XYZ normals in RGB: (128, 128, 255) faces the screen; red points right and green points up. Keep the RGB vector normalized and use opaque pixels wherever the matching artwork is visible. Flipping, negative scale and sprite rotation also transform the normal direction.

DeferredAnimatedMaterial accepts either one normal animation or a dictionary keyed by the animator's animation names. Content-owned Aseprite atlases are shared by path, layer selection and visibility setting. Identical full frames reuse atlas regions while keeping frame order, durations, tags and origins. Consumers must not dispose them. The component owns and disposes only its material, restoring the previous material when disabled or removed.

For an animator that loads several character files, add entries to Clips. Each entry stores the gameplay animation name, a GUID-backed source, its tag and the hidden normal layers. An empty tag is supported for untagged sources. Explicit clip entries override the matching single-source animation binding.

For pixel art, start with restrained volumes for limbs, clothing and faces. Judge the result with a moving side light and through the whole animation. Avoid deriving height directly from painted brightness: dark clothing and baked shadows do not necessarily indicate a recessed surface. The Slice Back developers describe character normal maps, limited shading tones and Aseprite workflows. The SpriteIlluminator animation tutorial explains matched normal atlases and light-direction shading.