How to make seamless textures for your game with AI

A texture that looks great as one square can look terrible on a floor. Repeat it twenty times and every flaw repeats with it: a hard line where the edges meet, a dark corner from baked-in light, one bright pebble that turns into a grid of bright pebbles. Image models also love perspective and drama, which is the opposite of what a tile needs. This guide makes one anchor texture with the prompt words that keep it flat and even, builds a matching set from it, checks the seam the way a texture artist does, adds a normal map for free, and tiles it at the right scale in the engine.

The chain

Step	Model	Why this model	Cost
1. Anchor texture	Nano Banana 2.1 `image/nano-banana-2.1`	Sharp and faithful to a long prompt, and on Nano Banana models the same seed repeats a look, so the anchor is easy to come back to.	$0.04
2. Matching textures x 5	Nano Banana 2.1 `image/nano-banana-2.1`	Edits from the anchor picture, so the brush work, palette and light carry into every new material.	$0.20
		Total	$0.24

$0.24 for the whole chain, at each model’s list price:

Anchor texture: $0.04 ($0.04 per image)
Matching textures x 5: $0.20 ($0.04 per image, 5 jobs)

A failed job costs nothing. Before you run anything, price each step exactly and for free: summer api estimate <model> --input '<json>', or POST /v1/estimate with the same body as the job. Prices come from GET /v1/models and change only when the provider’s price does. The normal maps cost nothing: the free normal map generator makes them in your browser.

Before you start

npx -y summer-engine@latest login

Your browser opens the Summer sign-in. Pick a spend limit for this computer and choose Allow. Using a coding agent? Paste this guide’s URL and say “make me a forest texture set”; the quickstart for your agent connects it in one command. Decide two things first:

The list of surfaces. Ground, wall, path, wood, roof, rock: one line each, with the material and how worn it is.
The style sentence. One sentence for the look, such as “Stylized hand-painted game texture, soft painterly detail, muted greens and warm browns”. It goes into every prompt, word for word.

Step 1: one anchor texture, flat and even

The anchor is the texture that sets the look for the whole set. Pick the surface the player sees most, usually the ground. Every word in the prompt has a job:

“Seamless tileable texture” tells the model the picture will repeat.
“Straight top-down view” (or “straight front view” for walls) removes perspective. A floor that shrinks toward a horizon can never tile.
“Flat even overcast light, no cast shadows, no vignette” removes baked light. A shadow in one corner becomes a stripe of shadows across the whole floor.
“No single standout feature” stops the model from adding one hero rock, one flower or one crack. Those are the details the eye catches when they repeat.
“Spread evenly” and “filled edge to edge” keep detail all the way to the borders, where the seam is.

Keep aspectRatio at 1:1: tiles are square. Set a seed and write it down. On Nano Banana models the same seed and prompt give a similar picture, so you can make small prompt changes without losing the look.

npx -y summer-engine@latest api run image/nano-banana-2.1 \
  --input '{"prompt":"Forest floor ground texture: packed dark soil, small pebbles, fallen pine needles and short moss spread evenly across the whole square. Seamless tileable texture, straight top-down view, flat even overcast light, no perspective, no cast shadows, no vignette, no single standout feature, filled edge to edge. Stylized hand-painted game texture, soft painterly detail, muted greens and warm browns.","aspectRatio":"1:1","seed":4127,"title":"Forest floor"}' \
  --download .

curl https://www.summerengine.com/v1/jobs \
  -H "Authorization: Bearer $SUMMER_TOKEN" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Prefer: wait=60" \
  -d '{"model":"image/nano-banana-2.1","input":{"prompt":"Forest floor ground texture: packed dark soil, small pebbles, fallen pine needles and short moss spread evenly across the whole square. Seamless tileable texture, straight top-down view, flat even overcast light, no perspective, no cast shadows, no vignette, no single standout feature, filled edge to edge. Stylized hand-painted game texture, soft painterly detail, muted greens and warm browns.","aspectRatio":"1:1","seed":4127,"title":"Forest floor"}}'

const res = await fetch("https://www.summerengine.com/v1/jobs", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.SUMMER_TOKEN}`,
    "Content-Type": "application/json",
    "Idempotency-Key": crypto.randomUUID(),
    Prefer: "wait=60",
  },
  body: JSON.stringify({
    "model": "image/nano-banana-2.1",
    "input": {
      "prompt": "Forest floor ground texture: packed dark soil, small pebbles, fallen pine needles and short moss spread evenly across the whole square. Seamless tileable texture, straight top-down view, flat even overcast light, no perspective, no cast shadows, no vignette, no single standout feature, filled edge to edge. Stylized hand-painted game texture, soft painterly detail, muted greens and warm browns.",
      "aspectRatio": "1:1",
      "seed": 4127,
      "title": "Forest floor"
    }
  }),
});
const { job } = await res.json();
console.log(job.state, job.id);

import os, uuid, requests

res = requests.post(
    "https://www.summerengine.com/v1/jobs",
    headers={
        "Authorization": f"Bearer {os.environ['SUMMER_TOKEN']}",
        "Idempotency-Key": str(uuid.uuid4()),
        "Prefer": "wait=60",
    },
    json={"model": "image/nano-banana-2.1", "input": {"prompt": "Forest floor ground texture: packed dark soil, small pebbles, fallen pine needles and short moss spread evenly across the whole square. Seamless tileable texture, straight top-down view, flat even overcast light, no perspective, no cast shadows, no vignette, no single standout feature, filled edge to edge. Stylized hand-painted game texture, soft painterly detail, muted greens and warm browns.", "aspectRatio": "1:1", "seed": 4127, "title": "Forest floor"}},
)
job = res.json()["job"]
print(job["state"], job["id"])

// Summer's MCP server: npx -y summer-engine@latest setup <agent> --yes
summer_api_run({
  model: "image/nano-banana-2.1",
  input: {
    prompt: "Forest floor ground texture: packed dark soil, small pebbles, fallen pine needles and short moss spread evenly across the whole square. Seamless tileable texture, straight top-down view, flat even overcast light, no perspective, no cast shadows, no vignette, no single standout feature, filled edge to edge. Stylized hand-painted game texture, soft painterly detail, muted greens and warm browns.",
    aspectRatio: "1:1",
    seed: 4127,
    title: "Forest floor"
  },
  out: "assets",
})

Not right? Change one phrase at a time. A texture costs $0.04 per image, so make five anchors and pick the best one before you build the set on it. Other models for this step. FLUX 3 is strong on photoreal and painterly surfaces ($0.048 per image). Grok Imagine makes fast surface ideas at a low price per picture ($0.02 per image), good for trying ten materials before you commit to a style. FLUX 3 Klein is the cheapest way to draft ($0.009 per image). Only Nano Banana models repeat a look from a seed; on the others, the reference picture in step 2 does that work.

Step 2: the matching set, from the anchor

Separate prompts give separate games: a painterly floor next to a photo-like wall. Instead, send the anchor as referenceImageUrl on every other texture. The model copies the brush work, palette, light and level of detail from the picture, and the prompt changes only the material. Start the prompt with “A new texture in exactly the same style, palette, light and level of detail as this picture”, then name the new surface. Keep the same seed and the same seamless words.

npx -y summer-engine@latest api run image/nano-banana-2.1 \
  --input '{"prompt":"A new texture in exactly the same style, palette, light and level of detail as this picture: a mossy stone brick wall, rows of rounded grey stones with thin dark mortar lines, moss in a few cracks, spread evenly. Seamless tileable texture, straight front view, flat even overcast light, no perspective, no cast shadows, no vignette, no single standout feature, filled edge to edge.","referenceImageUrl":"<fileUrl of anchor texture>","aspectRatio":"1:1","seed":4127,"title":"Mossy stone wall"}' \
  --download .

curl https://www.summerengine.com/v1/jobs \
  -H "Authorization: Bearer $SUMMER_TOKEN" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Prefer: wait=60" \
  -d '{"model":"image/nano-banana-2.1","input":{"prompt":"A new texture in exactly the same style, palette, light and level of detail as this picture: a mossy stone brick wall, rows of rounded grey stones with thin dark mortar lines, moss in a few cracks, spread evenly. Seamless tileable texture, straight front view, flat even overcast light, no perspective, no cast shadows, no vignette, no single standout feature, filled edge to edge.","referenceImageUrl":"<fileUrl of anchor texture>","aspectRatio":"1:1","seed":4127,"title":"Mossy stone wall"}}'

const res = await fetch("https://www.summerengine.com/v1/jobs", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.SUMMER_TOKEN}`,
    "Content-Type": "application/json",
    "Idempotency-Key": crypto.randomUUID(),
    Prefer: "wait=60",
  },
  body: JSON.stringify({
    "model": "image/nano-banana-2.1",
    "input": {
      "prompt": "A new texture in exactly the same style, palette, light and level of detail as this picture: a mossy stone brick wall, rows of rounded grey stones with thin dark mortar lines, moss in a few cracks, spread evenly. Seamless tileable texture, straight front view, flat even overcast light, no perspective, no cast shadows, no vignette, no single standout feature, filled edge to edge.",
      "referenceImageUrl": "<fileUrl of anchor texture>",
      "aspectRatio": "1:1",
      "seed": 4127,
      "title": "Mossy stone wall"
    }
  }),
});
const { job } = await res.json();
console.log(job.state, job.id);

import os, uuid, requests

res = requests.post(
    "https://www.summerengine.com/v1/jobs",
    headers={
        "Authorization": f"Bearer {os.environ['SUMMER_TOKEN']}",
        "Idempotency-Key": str(uuid.uuid4()),
        "Prefer": "wait=60",
    },
    json={"model": "image/nano-banana-2.1", "input": {"prompt": "A new texture in exactly the same style, palette, light and level of detail as this picture: a mossy stone brick wall, rows of rounded grey stones with thin dark mortar lines, moss in a few cracks, spread evenly. Seamless tileable texture, straight front view, flat even overcast light, no perspective, no cast shadows, no vignette, no single standout feature, filled edge to edge.", "referenceImageUrl": "<fileUrl of anchor texture>", "aspectRatio": "1:1", "seed": 4127, "title": "Mossy stone wall"}},
)
job = res.json()["job"]
print(job["state"], job["id"])

// Summer's MCP server: npx -y summer-engine@latest setup <agent> --yes
summer_api_run({
  model: "image/nano-banana-2.1",
  input: {
    prompt: "A new texture in exactly the same style, palette, light and level of detail as this picture: a mossy stone brick wall, rows of rounded grey stones with thin dark mortar lines, moss in a few cracks, spread evenly. Seamless tileable texture, straight front view, flat even overcast light, no perspective, no cast shadows, no vignette, no single standout feature, filled edge to edge.",
    referenceImageUrl: "<fileUrl of anchor texture>",
    aspectRatio: "1:1",
    seed: 4127,
    title: "Mossy stone wall"
  },
  out: "assets",
})

For each surface, change only the middle of the prompt:

Surface	The words to change
Path	worn cobblestones of mixed sizes, packed dirt between them
Wood	weathered horizontal oak planks, soft grain, a few nail heads spread evenly
Roof	overlapping clay roof tiles in even rows, a little moss
Rock	rough grey cliff rock, cracks running in many directions
Sand	dry sand with small ripples and scattered tiny shells

Bricks, planks and tiles are patterns with rows. Tell the model the rows run straight and evenly across the picture, or the last row gets cut in half at the edge.

Check the seam before you use it

Never trust a texture from one square. Two quick checks find every seam. Tile it. Repeat the texture three by three and look at the big picture from a distance. With ImageMagick:

magick -size 3072x3072 tile:forest_floor.png forest_floor_tiled.png

Look for straight lines at the edges, a grid of the same bright spot, or a light and dark checker pattern. A checker means the light was not even. A grid of spots means a standout feature. Roll it. Move the texture by half its size, so the four edges meet in the middle, where you can see them:

magick forest_floor.png -roll +512+512 forest_floor_rolled.png

A good tile shows nothing in the middle. A bad tile shows a cross. Fix a small seam. Paint over the cross in the rolled picture with a healing brush in any image editor, then roll it back by the same amount. The edges now match by construction, because the new edges are pixels that already sat next to each other. For a large seam, run the anchor again with more weight on “seamless tileable, filled edge to edge, no single standout feature”. Fixing a picture by hand takes five minutes; it is often faster than five more takes. Inside a Summer Engine project, the tileable-texture skill makes the texture, checks it tiled and wires it onto a floor or a wall for you.

Normal maps, for free

The models make the colour texture (the albedo) only. Light on a flat colour texture looks flat. A normal map adds the bumps: the gaps between stones catch shadow, planks get an edge, and the whole surface reacts to your lights. Open the free normal map generator, drop your texture in, and download the normal map. It runs in your browser. Then:

Keep the strength low for stylized art. Painted textures already have light painted in. A strong normal map on top looks noisy.
Check the direction. Summer Engine reads normal maps with green pointing up. If the bumps look dented, as if light came from below, invert the green channel.
Make one per texture. A normal map follows its own texture, so the set of six textures needs six normal maps.

The tiling holds: a normal map made from a seamless texture tiles too.

Put it in your game

Summer Engine. Drop the PNG files into your project. In the import dock, keep mipmaps on and use VRAM compressed for textures you use in 3D; mipmaps stop the shimmer on a floor seen from far away. Then make a StandardMaterial3D and set its scale to the size of the surface:

var mat := StandardMaterial3D.new()
mat.albedo_texture = load("res://art/textures/forest_floor.png")
mat.normal_enabled = true
mat.normal_texture = load("res://art/textures/forest_floor_normal.png")
mat.uv1_scale = Vector3(20, 20, 1)  # a 20 m floor, one tile per metre
$Floor.material_override = mat

The scale is the whole trick. A tile of forest floor should cover about one to two metres; a brick wall tile about one metre wide. On a 20 m plane, uv1_scale of 20 gives one tile per metre. Leave it at 1 and one picture stretches across the whole floor and looks blurry. Two more settings that help:

Triplanar mapping (mat.uv1_triplanar = true) projects the texture from three sides. Use it on rocks, cliffs and generated meshes whose UVs stretch.
Break the repeat. Make three versions of the ground from the same anchor and seed (numImages: 3), and paint them across the level, or add a second texture at a different scale on the material’s detail layer. The eye stops seeing the grid.

Any other engine. The PNG tiles in any engine. Set the texture’s wrap mode to repeat, turn on mipmaps, and set the material’s tiling to the surface size in metres. Pixel-art games. Use the pixel-art skill’s prompt pattern instead, with a named palette and “no anti-aliasing”, and set the texture filter to nearest.

Make a whole biome

A biome is ten to twenty textures: two or three grounds, walls, paths, a cliff, wood, a roof, details. Write one JSONL file, one job per line, every line with the anchor’s fileUrl as referenceImageUrl, the same seed and the same style words:

{"model": "image/nano-banana-2.1", "input": {"prompt": "A new texture in exactly the same style, palette, light and level of detail as this picture: worn cobblestones of mixed sizes, packed dirt between them. Seamless tileable texture, straight top-down view, flat even overcast light, no perspective, no cast shadows, no single standout feature, filled edge to edge.", "referenceImageUrl": "<fileUrl of the anchor>", "seed": 4127, "title": "Cobble path"}}
{"model": "image/nano-banana-2.1", "input": {"prompt": "A new texture in exactly the same style, palette, light and level of detail as this picture: weathered horizontal oak planks in straight even rows, soft grain. Seamless tileable texture, straight front view, flat even overcast light, no perspective, no cast shadows, no single standout feature, filled edge to edge.", "referenceImageUrl": "<fileUrl of the anchor>", "seed": 4127, "title": "Oak planks"}}

npx -y summer-engine@latest api run --batch biome.jsonl --download art/textures

A batch takes up to 500 jobs, is priced when it arrives and runs all or none, so you know the total first (batches). A sky to go with it is a separate job: the skybox-panorama skill covers it.

Common problems

You see	Do this
A hard line at the edges	Roll the texture by half and heal the cross, or run it again with “filled edge to edge”
A light and dark checker when tiled	Baked light. Add “flat even overcast light, no cast shadows, no vignette”
The same rock repeats in a grid	Add “no single standout feature, spread evenly”. Make three versions and mix them
The floor shrinks toward a horizon	Add “straight top-down view, no perspective”
Bricks cut in half at the border	Say “straight even rows across the whole picture”
The new texture does not match the set	Send the anchor as `referenceImageUrl`, start the prompt with “in exactly the same style”, keep the seed
Blurry or stretched on the floor	Raise the material’s UV scale to the surface size in metres; keep mipmaps on
Bumps look dented	Invert the green channel of the normal map

Questions

Can I get a full PBR set, with roughness and height? The models make the colour texture. The normal map generator adds the normal map. For most stylized games, colour plus normal is enough; set roughness as one number on the material. What size are the textures? Square pictures at the model’s normal size, usually about 1024 px. For a larger tile, pass both width and height (up to 4096); read the model’s page for the sizes it reaches. On mobile and web, a 1024 px tile with mipmaps is plenty. Can I make a texture from a photo? Yes. Upload the photo (send a picture) and run step 2 with it as the reference and a prompt that says “a seamless tileable texture of the surface in this photo, straight top-down view, flat even light”. Can I use the textures in a commercial game? Yes. Every model on the Summer API allows commercial use of what it makes.

Start here

How to make

Models and pricing

Use the API

API reference

How to make seamless textures for your game with AI

The chain

Before you start

Step 1: one anchor texture, flat and even

Step 2: the matching set, from the anchor

Check the seam before you use it

Normal maps, for free

Put it in your game

Make a whole biome

Common problems

Questions

​The chain

​Before you start

​Step 1: one anchor texture, flat and even

​Step 2: the matching set, from the anchor

​Check the seam before you use it

​Normal maps, for free

​Put it in your game

​Make a whole biome

​Common problems

​Questions

The chain

Before you start

Step 1: one anchor texture, flat and even

Step 2: the matching set, from the anchor

Check the seam before you use it

Normal maps, for free

Put it in your game

Make a whole biome

Common problems

Questions