Cosmic StarBox Generator

Build deep-space skyboxes inside Unity, in seconds, without ever leaving the editor.

WEBGL Demo

Cosmic SkyBox Generator is a procedural cubemap authoring tool and a parallax space shader in one package. You stack nebula layers, star layers and image layers in a dedicated editor window, watch a live 256 px preview update as you drag sliders, then bake the result to an HDR cubemap and render it through a skybox shader that ships for Built-in, URP and HDRP.

DROP IN ANY IMAGE YOU LIKE

Every sky can carry your own textures. Take a public-domain NASA plate, a Hubble galaxy, a painted nebula, a planet render, a logo — assign it to a Textured Layer, set its angular size and position on the sphere, pick a blend mode, and it is projected straight into the cubemap alongside the procedural content. Black is treated as fully transparent, so cut-outs need no alpha work. Layers can be drawn before the nebulae, before the stars, or on top of everything.

PARALLAX THAT ACTUALLY MOVES

The included parallax skybox shader samples three separate cubemaps — deep space, far stars, near stars — and shifts each one by its own amount as the camera turns. The result is a sky with real depth: distant nebulae sit still while foreground star fields drift across them. No script, no companion component, no per-frame setup. The effect is driven entirely from the view matrix, so it works in the editor, in play mode, and in builds identically.

ONE CLICK, THREE LAYERS

Assign each layer a parallax group — Background, Middle or Foreground — and the generator splits the bake automatically. Four cubemaps are written and dropped straight into the right material slots. You keep authoring one sky; the tool sorts out the depth separation for you.

ALL THREE PIPELINES

Built-in, URP and HDRP each get their own shader variant exposing identical parameters. The HDRP version registers as a native sky type through the volume framework, complete with a custom sky renderer, correct sun injection and seam-free reflection baking. Each shader declares its package requirement, so uninstalled pipelines are skipped instead of throwing import errors.

BUILT FOR ITERATION

Settings save and load as JSON presets. The generator runs cube-face rasterisation on Parallel.For. Auto Update Preview re-bakes a fast 256 px sky half a second after your last slider move, so tuning a nebula feels immediate. When you like it, hit Generate and get the full-resolution cubemap.

Output is a proper RGBAHalf DDS cubemap with a DX10 header, so nothing is clipped, HDR bloom has real values to work with, and the file imports cleanly into Unity 6.

Full source included. C# and HLSL, readable, no DLLs.