Krotox Engine › Docs › Krotox Manual › The Editor

Assets, textures & sprite atlases

How Krotox tracks assets with .meta files, the texture import settings and presets, packing sprites into an atlas, and auditing what your build will contain.

Everything your game uses lives under the project's Assets/ folder: images, audio, fonts, scenes, prefabs, scripts and data assets. This page covers how Krotox keeps track of them and how to prepare textures for 2D.

How assets are tracked

Every asset is identified by a random 64-bit asset handle, not by its file name. The handle is stored in a .meta file (YAML) next to the asset:

Assets/Textures/player.png
Assets/Textures/player.png.meta     <- keeps player.png's handle

Scenes and prefabs refer to assets by handle. Because the handle survives renames, moves and other machines, a scene keeps pointing at the right texture after you reorganize folders or a teammate pulls your changes.

Always commit .meta files with their assets, and move or rename assets inside the Content Browser rather than in your file manager when you can. A lost .meta file gives the asset a new handle, and every reference to the old one breaks.

Adding assets

Copy files into Assets/ (or a subfolder) with your file manager, or drag them into the Content Browser. The editor picks them up and creates their .meta files.

Kind	Formats
Images	.png, .jpg / .jpeg, .bmp
Audio	.wav, .mp3, .ogg, .flac
Scenes and prefabs	.ktx, .prefab
Scripts	.cs
Data assets	.ktxasset (ScriptableObject)
Animation	.ktxanim, .ktxanimctrl

The Content Browser labels each thumbnail with a type badge (Scene, Prefab, C#, Audio, Anim, Texture) and can filter by type.

Texture import settings

Select one or more textures in the Content Browser and open View ▸ Import. Changes apply to every selected texture; press Apply Settings to save them, or Rebake / Reimport Texture to rebuild the texture now.

Compression

Mode	What it does	Use it for
Lossless	Exact pixels, stored as the original file. Full RGBA8 in video memory.	Pixel art, UI, anything with sharp edges or flat colours.
Lossy	Re-encoded as JPEG with a Quality setting. Much smaller download, but full size once decoded.	Large photographic backgrounds where download size matters.
VRAM Compressed	Block-compressed and kept compressed on the GPU, using 4–8× less video memory. ASTC on Android. Has a VRAM Quality setting: Fast, Balanced or High.	Big textures on phones, where memory is tight.
VRAM Uncompressed	Raw RGBA8 on disk too. Largest files, nothing to decode at load.	Rare; textures that must load as fast as possible.

Other settings

• Generate Mipmaps: smaller pre-filtered copies for textures that are drawn far smaller than their size. Usually off for 2D sprites drawn at their natural size, and always off for pixel art.
• sRGB: the texture holds colours (on for sprites and UI). Turn it off for data textures such as masks.
• Load Mode: Immediate streams the texture as soon as anything references it, including when the scene opens. Lazy waits until something actually draws it, so opening a scene stays fast.

Quick presets

Preset	Sets up
Pixel Art / UI	Exact pixels with no mipmaps, so edges stay crisp.
Photographic Art	Settings for smooth, photographic images, with mipmaps.
VRAM Compressed	GPU block compression.
3D / Uncompressed	Uncompressed, for 3D materials.

For pixel-art games, also set the project's scaling mode to Pixel Perfect so the whole screen scales in whole-number steps. See Windows builds, resolution & scaling.

Sprite sheets

A sprite sheet is one image holding many frames in a grid. The Sprite Renderer can draw a single cell: turn on Use Sub Texture, set the Cell Size in pixels (for example 16×16), pick the cell with Sub Texture Coords, and set Sprite Size to the number of cells the sprite spans (2, 1 for a 32×16 sprite on a 16×16 grid). The Animated Sprite component plays a sequence of cells. See the 2D component reference.

Packing an atlas

Many small images cost more than one big one: each texture change can break a draw batch. The atlas generator packs images into a single sheet.

1. Select several images in the Content Browser, or right-click a folder.
2. Choose Generate Texture Atlas…. A packer window opens; nothing is written yet.
3. Adjust the settings and watch the preview.
4. Press Generate Atlas.

Setting	What it does
Padding	Transparent gap between sprites. A sample near a sprite's edge reaches into its neighbour, so with no gap you see colour bleeding. 2 px suits most filtered atlases; pixel art with nearest filtering can use 0.
Extrude	Repeats each sprite's border pixels into the gap, so filtering blends toward the sprite's own edge colour instead of a dark fringe. Capped at the padding.
Max Size, Power of Two, Force Square	Limits and shape of the sheet.
Sort order	Height, area or name. Name packs less tightly but gives a stable layout that diffs well in version control.

The preview draws the sheet on a checkerboard with each sprite's bounds and gap. Hover a sprite for its name and source rectangle. The occupancy bar shows how much of the sheet is real sprite pixels, so you can see what padding and power-of-two rounding cost.

Auditing assets

Tools ▸ Asset Dependency Visualizer... shows how assets reference each other across the whole project.

• The left column lists every asset with a health badge: Healthy, Orphaned (nothing uses it), Circular, Missing (a reference points at nothing) or Large.
• Dependencies shows what the selected asset uses, and Dependents what uses it.
• Dependency Graph draws the reference graph.
• Health Analysis finds circular references, orphaned files and missing references.
• Build Report lists exactly which assets ship in a build and their sizes, including everything they pull in.

Check the Build Report before shipping. It is the quickest way to find the one oversized background that doubles your data.pak.

ScriptableObject data assets

For shared game data (weapon stats, level tables, dialogue), right-click in the Content Browser and choose Create Scriptable Object. It creates a .ktxasset from one of your C# classes, edited in the Scriptable Object panel. Scripts reference it from an inspector field. See Prefabs, scenes & saving.

Clearing the cache

Cache/ holds generated data: the compiled shader cache, font atlases and auto-save copies. File ▸ Clear Project Cache deletes it; the editor rebuilds what it needs. Try it first when something looks stale after an update.