PLEASE READ AND ADHERE TO THE USAGE REQUIREMENTS BELOW BEFORE REPORTING ISSUES!!!! 

It's finally here, sorry for the long wait! This update is fairly simple, but the new features took a ton of research, fine-tuning and adjustments to ensure they work well in all situations. Of course, I'm talking about the new sky and clouds! Please keep in mind that they're band-new features that I still want to put a lot more work into. Unfortunately, they turned out to be a little heavier on performance than I expected them to. Of course, you can turn them off.

I also put in a lot of effort into optimization into this update. Each performance improvement and new feature is more advanced than the last, so at this point of the project, sometimes it takes a lot more work to get the same kind of gains. In this case, performance may overall be slightly worse with clouds enabled and default settings. The potential gains come with using high resolution resource packs with Full Raytrace Reflections on. So, depending on the situation and your settings, you may see a speedup or a slowdown. 

Here's the changelog:

• Rough reflections now lookup a lower resolution version of block textures, leading to improved performance with Full Raytrace Reflections: On
• Completely redesigned sky and clouds
• Clouds now contribute to reflections and diffuse GI
• Added options controlling clouds into a new options section: Atmospherics Options
• Moved Atmospheric Godrays option to Atmospheric Options
• Diffuse GI filter no longer shows a weird outline highlight around objects in front of lit blocks
• Exposure can now adjust to brighter scenes
• New diffuse GI filter algorithm that should be a little faster and smoother but look the same
• Ray traced reflections now use a clamped GGX distribution instead of phong
• Unlit campfires no longer give off GI light

PLEASE READ THE FOLLOWING REQUIREMENTS FOR USING THIS SHADER PACK!

• Minecraft 1.14.4 (older version compatibility is work in progress)
• OptiFine HD U F3 or newer
• Options > Video Settings > Details > Alternate Blocks: OFF
• Options > Video Settings > Details > Trees: Fancy or Fast (Smart may break lighting)
• Options > Video Settings > Quality > Natural Textures: OFF
• Options > Video Settings > Shaders > Shadow Quality: 1x
• Options > Video Settings > Shaders > Old Lighting : DEFAULT
• Resource packs with custom block models will probably cause  lighting glitches!!!!!!

Some of the currently known issues are as follows:

• Block texture alpha is not considered in diffuse GI tracing, so doors and trapdoors don't let any light through their windows currently.
• Being underwater in ravines/caves shows some light leaking, and “glowing” water fog. This is unavoidable currently.
• "Disco Floor" flickering artifact mostly seen in reflections (the new Secondary GI Samples option can help with this)
• Secondary GI bounces (2nd bounce and onward) can take a while to adapt to lighting changes
• Issues with the rendering of semi-transparent/translucent materials
• Lighting breaks often when using resource packs with custom models, a solution is being investigated!

AN IMPORTANT NOTE ON GRAPHICS DRIVER ISSUES AND GPU COMPATIBILITY:

Since different GPUs can compile shaders differently than others, you may experience compile errors (causes "[Shaders] Error: Invalid program..." messages to appear in the in-game chat). 

If you experience compile errors and you're using an NVIDIA GPU, you can help me fix them by following the steps on this page, in the "How to Report a Compile Error" drop-down section and sending me the log!

Compatibility with AMD GPUs is being actively worked on. You will still experience some minor visual bugs, and you may experience random crashing. If you experience crashing while trying to load the game or enable SEUS PTGI, try doing so first in windowed mode, with a small window.

Compatibility with Intel GPUs is not guaranteed or planned at all!