What is a 2D normal map for a sprite?

A 2D normal map tells an engine which way each pixel of a sprite is facing, so a light can travel across it. Totally Normal Mapper builds that map from the sprite outline and the line work rather than from brightness.

How do I generate a normal map from a 2D sprite?

Open the sprite, let the tool solve from the silhouette and line work, paint any overlaps the outline gets wrong, then export for your engine. Getting started walks through it.

2D normal map editor · sprites

Normal maps for pixel art and painted sprites.

Drawn art already has lighting decisions in it. This tool builds a surface from the outline, then lets you paint the rest: an arm in front of a body, a flat wall, a fold that is only ink.

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Platform: Windows and Linux. Steam Deck runs the Windows version through Proton. macOS is planned.
Engines: Unity · Godot 4 · Unreal Engine 5 · OpenGL · DirectX

Lit previewMove the light

A real export, lit here with one light. Move your pointer to drag it.

Orbit

The same export, lit from every side. Only the light direction changes.

In motion

The same map, under a moving light

Height-from-brightness maps often look stamped on. This one has volume. The body rounds, and the arm sits in front of the torso.

What it does

Sprite work

Painted lighting stays in the colour

Line detection uses colour, so a dark wash is not read as an inked fold. Edges are found without blurring the sprite.

Sharp at the sprite's own size

A 32×32 sprite exports as a 32×32 normal map. The pixels stay hard.

A preview you can light

Drag lights across the artwork. Switch between art, lit, normal, height, AO, spec, and split before you export.

Several sprites, each its own object

Import them as layers. Each is solved separately, with its own hints and settings, then stacked. A prop in front of a character is two silhouettes, not one asked to invent a relationship.

Height, AO, and specular from the same solve

Inspect them as greyscale views. Optionally fold them into the lit preview. Export them beside the normal map. Unity 2D has no spec slot, so AO and spec pack into one Mask Map: red is spec, green is AO.

Consistent animation frames

Load every frame together. Settings stay shared so the frames agree, hints stay per frame, and one export writes the set.

Photoshop and Aseprite import

Open a PSD or .aseprite file and assign each layer as artwork, as a hint, or skip it. Edit the file and re-read it instead of tracing the same masks again.

A batch tool in the install

Dial in the look on one sprite, then apply it to a folder of two hundred with tnmap, the command-line tool installed beside the editor. Same solver, same presets, same export targets.

The usual approach

Brightness is a poor stand-in for height

On a photo of stone, dark really can mean recessed. On a drawing, dark is often just paint. A generator that cannot tell those apart will carve your shading into the mesh and ignore the shape you drew.

The artwork — **The same sprite, three ways.** The middle panel is brightness treated as height with a Sobel gradient, which is the usual method. It has almost no sense that the subject is round.

Brightness as height — **The same sprite, three ways.** The middle panel is brightness treated as height with a Sobel gradient, which is the usual method. It has almost no sense that the subject is round.

Hints

Paint the overlaps the outline gets wrong

An overlapping arm looks like a crease in one surface. Paint it with In front and that edge stops folding the torso.

Without the hint — **The overlap, the hint, and the map.** Fourteen layers. Each one is a region you fill. See Painting hints.

What you paint — **The overlap, the hint, and the map.** Fourteen layers. Each one is a region you fill. See Painting hints.

Photoshop & Aseprite

Bring in the layers you already have

A hint has to match the artwork exactly. If those shapes already live in Photoshop or Aseprite, import the .psd or .aseprite file and assign each layer: as a hint, as the base artwork, or as its own object on the canvas.

Selections, masks, and shapes you already painted can become hints. Edit the file, come back, and re-read it.

armIn front

eye L · eye RConvex area

ear socketConcave area

belt buckleFlatten

line artAdd stroke

A layer’s own shape is usually the hint. Naming it after the hint it feeds fills the dialog in for you. Anything left unassigned stays artwork. See Importing artwork.

Compatibility

Export that matches your engine

Green-up versus green-down is a single bit, and the wrong one makes every bump look like a dent. Choose the engine on export. The import settings a PNG cannot carry travel with the file.

Unity

Y+

Set Texture Type to Normal Map and leave Flip Green Channel off. AO and spec pack into a Mask Map (_MaskTex): red is spec, green is AO.

Godot 4

Y+

Leave Normal Map Invert Y off. Godot discards the blue channel, and exports stay valid without it.

Unreal Engine 5

Y-

Set Texture Group to WorldNormalMap. The flip is already in the file, so leave Flip Green Channel off.

OpenGL

Y+

Raw Y+, matching Blender and most offline renderers.

DirectX

Y-

Raw Y-, matching 3ds Max and Source 2.

Not sure which your pipeline wants? Export a calibration target once and compare it against the reference on the Exporting page.

Support

When something looks wrong

The documentation covers every tool and setting. Start there; most odd results are a control doing what it says.

Wishlist on Steam Getting started

Documentation

Start here. Every tool, every setting, the batch tool, and a troubleshooting page for results that look wrong.

Email

support@goathollowgames.com. A sprite that reproduces the problem, or the project file, gets a much faster answer than a description. If the window went blank, attach last-crash.txt from the folder named in Help ▸ About.

Steam community

Discussions on the store page. Best place for workflow questions and for asking after a feature.