Physical Starlight and Atmosphere is a completely volumetric procedural sky, sunlight, and atmosphere simulator for Blender. It has been actively perfected for over 10 years already and since its release has been the go-to lighting tool for many independent artists to highly skilled professionals and studios.
Create your world by tweaking these parameters:

• Variable Sun size and brightness
• Binary Sun (extra rotating sun)
• Procedural Atmosphere (adjust atmosphere density, height color, and more)
• Stars (procedural or HDRI options supported)
• Basic Clouds procedurally generated (adjust scale, thickness, coverage, lighting location, and more)
• Procedural ground plane with variable height
  

BONUS INCLUDED – Premade presets:
A total of 10 presets are included (Earth, Mars, Nishita, Retrowave, and more)

Saves time
This addon saves hours that usually are invested in manually creating sky, atmosphere and placing sun object and stars, and automates it within a single click.Made by professionals
We have more than a decade of experience with atmosphere rendering techniques in the computer graphics industry. Physical Starlight and Atmosphere addon is used in entertainment, film, automotive, aerospace, and architectural visualization industries.Has premade presets
Presets allow you to store a snapshot of your customized atmosphere settings and return to it later or use already predefined presets provided by the addon.Highly customizable
We use a procedural method of calculating the atmosphere based on many tweakable parameters, so that sky color is not limited only to the Earth’s atmosphere.Well integrated
Works well in combination with Blender Sun Position addon. You can simulate any weather at any time.
Other features include:

• Visually accurate mathematical model
• Made for PBR and HDR workflow
• High dynamic range, use with tone mapping (filmic or aces)
• Earth shadow (belt of Venus)
• Unlocked viewer position – can simulate conditions at any altitude
• Consistency – sunlight, sky, and fog share the same parameters
• Performance – load and render faster than HDRI textures
• Small memory footprint