Notice: There has been a performance drop in Blender 4.1+ Eevee. The sky shader will take several minutes to fully build when first loading. It will progressively improve with usage. While editing your sky, its recommended to use Cycles with GPU, only one viewport sample is required. Updates to come.

Update 0.2.3  Blender.4.0 now available

• Fixed Stars compatibility
  
• Update Improved stars horizon
  

Update 0.2.2 (Blender.3.0+)

Important: Old scenes using using Procedural Sky System can be updated but will give different results. PSS Sun and moon lights will be replaced.

• New Moon glow with occluder
• New Moon texture scaling
• New Sky shift parameter
  
• New Moon separate to sun in shader. Moon no longer child of Sun.
• New Moon visibility parameter
• New Rotate sky parameter
• New Preset, 'Strawberry Sky"
• Update All presets have been updated
  
• Update Offer to change color management mode to Standard when adding a new sky
• Update-Moon curvature parameter limits should be increased
• Update Moon evening gradient visible during Day
• Update Moon shadow now scales with moon
• Update Cumulus should adheres to time
• Fixed Bug if no nodes in world shader
• Fixed Improved Sunset threshold for sun visibility
• Fixed Fix for deleted presets
• Fixed Fix sky day/night bias
• Fixed Moon angle broken
• Fixed Delete preset error in Blender 3.2
  
  

Update 0.2.1 now available (Blender.2.90+)

• Fixed issues when background/command line rendering. Add-on is no longer required to render.
  

0.2 now available (Blender.2.90+)

• New: Multi scene support.

You can now have multiple sky systems within a single project. World data should be single user plus Blender scenes will support a single Sun and Moon lamp, therefore its recommended that if using both night/day skies, they should be setup in separate scenes.

• New: Cumulus Roughness
• Blender 3.0 support
  
• FIXED: bug fixes regarding pre-existing objects
• cloud detail now has max limit of 6.0
• Star size now maxed at 100
• FIXED: Popup panel hot key settings in addon preferences
  

• Note: Not compatible with the older pre-addon shader. 
• Install like any other .zip add-on
• Looks great in both Cycles and Eevee. Eevee can take a minute to compile the shader when first loading whereas Cycles does not require compilation. The results will look identical in both engines.

Known Issues

• Shadow caster works best with Cycles. Eevee's shadow maps don't handle semi transparent shadows well and wil result in noise
• 'Auto lights' can be demanding on the GPU when tweaking parameters in the world tab as it forces continual updates. Using the hot key menu however doesn't trigger light rebuilding in Cycles.

Updates to come, this addon is being maintained.

Please report any bugs /issues and ideas. I'm also keen to see how people are using the addon and would love to display use case scenarios.

Keep up to date on Other Realms addon's and experiments:

https://twitter.com/OTrealms