Procedural Stars
Animated, procedural stars for Unity URP and HDRP — from red dwarfs to blue giants. Made to be the suns of your star systems, seen from a distance.
Unity 6.3 LTS or newer · URP and HDRP · Version [VERSION]
What it is
Procedural Stars renders stars that are alive: a granulated surface with active regions and coronal holes that slowly evolve, a soft corona around the disc and coronal loops rising over the limb. Size, temperature, activity and seed are set per star; the colour follows the temperature, from deep red to blue-white.
Each star is drawn as a single camera-facing billboard and raymarched in the pixel shader. It writes the depth of the sphere, so other objects sort correctly in front of and behind it. The surface is baked on the GPU in the background and shared between stars with the same profile, which keeps the cost per star low.
The stars are designed to be seen from a distance — as the suns of a solar system, a backdrop or a strategy map. They are not meant for flying into the surface.
Star classes
Five presets as starting points — every value can be changed freely.
Red dwarf
Orange dwarf
Sun-like
White star
Blue giant
Anything in between
The five classes are presets, not limits. Temperature, radius, activity and seed are continuous — every star between a cool red dwarf and a hot blue giant can be dialled in, in the inspector or from script.
Five view modes
Inspired by how solar observatories see the Sun. Set per star, switchable at runtime.
EUV 171 Å
The default look: loops, coronal holes, bright limb.
White light
Granulation, sunspots, faculae, limb darkening.
H-alpha
Fibrils, plages and prominences at the limb.
EUV 304 Å
Red-orange structure, stronger spicules.
X-ray
Only active regions and loops shine.
Quality levels
Choose per star or project-wide. Distant stars can stay cheap while the main sun gets the full look.
| Level | Surface | Corona | Loops | GPU time* |
|---|---|---|---|---|
| Minimal | baked, no raymarch | — | — | [MEASURED] |
| Low | baked, reduced | reduced volume | [TBD] | [MEASURED] |
| Medium | baked | reduced volume | [TBD] | [MEASURED] |
| High | baked, full | full volume | [TBD] | [MEASURED] |
| Ultra | baked, full | full volume | all | [MEASURED] |
* One star, [RESOLUTION], [GPU] — measured with the included Quality demo scene.
How it works
One billboard per star
No mesh: a single quad faces the camera and the sphere is raymarched in the pixel shader.
Per-pixel depth
The shader writes the sphere's depth, so planets and ships sort correctly in front and behind.
Baked in the background
Surface and corona are baked by compute shaders within a per-frame time budget and shared between stars.
Requirements
- Unity
- 6.3 LTS or newer
- Render pipeline
- URP and HDRP
- Graphics API
- [TESTED APIS]
- GPU
- Compute shaders required
- Stars per frame
- Up to 8
- Platforms tested
- [PLATFORMS]
Good to know
- Built for viewing from a distance; extreme close-ups are not the goal.
- The first frames after loading show a live or simplified surface until the bake is ready.
- Not tested on mobile or WebGL.
FAQ
Can I fly into the star?
No — the stars are designed for distant views. The camera can come reasonably close, but there is no surface or interior to fly through.
Does it light my scene?
[ANSWER — e.g. pairs with your own directional/point light; light colour can follow the star temperature]
Which render pipelines are supported?
Both URP and HDRP are supported from the first release. The tested Unity versions and graphics APIs are listed under Requirements.
Asset Store or direct — what is the difference?
Same package, same updates. Buying direct leaves a larger share for the game's development.