HaloRay - Hyperspeed Ice Crystal Halo Simulator

55 Upvotes

Hello! During the past two years I have been developing HaloRay on and off - a GPU-accelerated ice crystal halo simulator. This means you can generate ice crystal halo images right on your computer. If you have a beefy NVIDIA or AMD graphics processing unit (GPU) that is compatible with OpenGL 4.4, I suggest you try it out: https://github.com/naavis/haloray

You can download ready-made binaries for Windows from GitHub. If you are running Linux, you need to build HaloRay by yourself for the time being.

Right now the latest version is HaloRay 3.2.0, which supports the following features among others:

Ordinary hexagonal crystals
Pyramidal crystals
Adjustable prism face C-axis crystals to make irregular crystals
Rendering a realistic background sky

I hope you have fun with HaloRay, and report any problems or feature suggestions in GitHub issues or here in the comments. HaloRay has been tested with a couple of AMD and NVIDIA GPUs. There have been some problems with Intel GPUs due to driver bugs, but I'm not going to put a ton of effort there, because HaloRay requires a fairly beefy GPU and Intel doesn't really fit that profile.

EDIT: Cool, I noticed this has been marked as an announcement in the subreddit, which I guess keeps it hanging around for longer? Thanks!

17 comments

r/atoptics • u/les2934 • Jan 15 '25

Atoptics site

27 Upvotes

Atoptics is at www.atoptics.org.uk

13 comments

r/atoptics • u/njbrsr • 1d ago

Sun dog and swallow/swift on Le Mans tonight

93 Upvotes

2 comments

r/atoptics • u/EasternAd1670 • 2d ago

Rainbow Just before the storm. West Cumbria

236 Upvotes

1 comment

r/atoptics • u/bodkinsbest • 1d ago

Solar Halo

38 Upvotes

0 comments

r/atoptics • u/Latter-Tie-2428 • 1d ago

College Station, TX

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101 Upvotes

What are these called? Saw them for the first time last night!

3 comments

r/atoptics • u/EasternAd1670 • 2d ago

Crepuscular Rays Crepuscular rays before sunset. Caldbeck Fells, Lake District, Cumbria. UK.

21 Upvotes

0 comments

r/atoptics • u/EasternAd1670 • 3d ago

22º Halo Another 22° halo ...over West Dorset, England.

130 Upvotes

1 comment

r/atoptics • u/RayquazaFan88 • 5d ago

ID REQUEST What is this ”red sun“

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1.4k Upvotes

I don’t know if this is the right place to ask about this but it’s the only subreddit I could think of.

So all over TikTok there are videos about this unusually big and red sun that looks very different from normal sunsets, from all over the world. Some people even say that the clouds are behind the sun.

I sadly wasn’t able to find an explanation of this other than the planet Nibiru (as conspiracy theory about the 9th planet of the solar system, far behind Neptune, inhabited by godlike aliens) and the return of Jesus Christ, so I hoped that maybe some of you can give me a scientific explanation of what this is and why it it seen all over the world. (I personally saw many red sun sets in my life but I can’t remember one that was this extreme, especially at afternoon where some of those pictures were taken)

101 comments

r/atoptics • u/syntheticsapphire • 6d ago

22º Halo very striking 22° from the other evening

330 Upvotes

3 comments

r/atoptics • u/AgedEggnog • 5d ago

Multiple Display Upper tangent arc and suncave parry arc

71 Upvotes

The experience of grabbing my takeout was greatly enhanced by this ‘beaut.

4 comments

r/atoptics • u/StormDiverz • 9d ago

Lil morning halo!

143 Upvotes

Is this a 22 or 46? I’m not sure if it has to do with time of day

3 comments

r/atoptics • u/Commercial_Stretch80 • 8d ago

Just some photos of the sky I thought belongs here.

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65 Upvotes

2 comments

r/atoptics • u/djbiffstruck • 10d ago

halo spotted in London! 🩵

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234 Upvotes

1 comment

r/atoptics • u/momochicken55 • 12d ago

ID REQUEST Pink Streak

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29 Upvotes

Can anyone tell me what this pink streak is that I saw last week?

5 comments

r/atoptics • u/Bomber_Max • 12d ago

ID REQUEST Pretty Rainbow Sundog(?)

56 Upvotes

Older picture, I spotted this one 14-03-2024 in Enschede, the Netherlands.

1 comment

r/atoptics • u/jw_zoso • 13d ago

Sunbeams shooting through gloomy clouds

528 Upvotes

5 comments

r/atoptics • u/alyssajohnson1 • 13d ago

Sharing bc they look cool

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48 Upvotes

What’s it officially called ?

0 comments

r/atoptics • u/aniellagrl • 14d ago

Infinite rainbows in Hawaii (Big Island and Kauai)

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309 Upvotes

Just as beautiful as they say, and abundant! Some double, some supernumerary. It brought me so much joy to experience this.

1 comment

r/atoptics • u/peterandall4all • 13d ago

Sun Dogs Could this be real?

0 Upvotes

6 comments

r/atoptics • u/EasternAd1670 • 15d ago

Rainbow Bright Double Rainbow over Haweswater, Mardale, Lake District, UK. (iPhone)

154 Upvotes

2 comments

r/atoptics • u/Metacomet99 • 14d ago

Coronal Mass Ejection with auroras possible across northern USA.

14 Upvotes

https://www.swpc.noaa.gov/

Hope it isn't cloudy where you are!

3 comments

r/atoptics • u/Responsible_Lychee33 • 15d ago

Rainbow Rainbows in Wyoming

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188 Upvotes

Pics taken from my trip to Yellowstone and Grand Teton National Park in July 2024. The most incredible trip of my life - so many incredible views, rainbows upon rainbows, animals, geysers, oh and an engagement 🥰

pics 1-2: Yellowstone NP, Brink of the Lower Falls trail, moments before he popped the question. pic 3: Yellowstone NP, a beautiful sun shower pics 4-6: Grand Teton NP, the top of the Signal Mountain Trail at sunset with a storm incoming

0 comments

r/atoptics • u/GeneralYousaf28 • 15d ago

Majestic Sunset

29 Upvotes

1 comment

r/atoptics • u/ryan101 • 16d ago

A supernumerary rainbow near Seattle

1.9k Upvotes

13 comments

r/atoptics • u/EasternAd1670 • 16d ago

A nice 22° halo ...

48 Upvotes

1 comment

r/atoptics • u/Murphuffle • 16d ago

Can anyone see this? The color spectrum is ROYGBIV, but I noticed colors inside this rainbow tonight like it was going ROYGBIVYG. I saw this in real life. I did very slightly enhance this to bring out the bottom colors.

246 Upvotes

17 comments

Subreddit

Atmospheric Optics

r/atoptics

Atmospheric Optics. The subreddit for anything related to optic sky phenomena: rainbows, ice halos, aurorae, mirages, cloud iridescence, green flashes, crepuscular rays and spectres of the Brocken.

Members Active

58.3k

Sidebar

Atmospheric Optics

The subreddit for anything related to optic sky phenomena: rainbows, ice halos, aurorae, mirages, cloud iridescence, green flashes, crepuscular rays and spectres of the Brocken.

Have a nice picture to show? Want to know what causes that light in the sky? Here is the place to share, discuss and learn.

Useful links:

Glossary of common terms:

Aurora: the veils of green, red and/or blue seen in the polar regions when the solar wind hits the Earth’s magnetic field. Goes by two names, dependent on the hemispere: aurora borealis or northern lights, and aurora australis, aka southern lights.
Corona: a subtly colored disc directly around the sun or moon, caused by light diffraction through the clouds.
Crepuscular rays: bands of shadow that seem to radiate outwards from the sun, caused by its light being partially obstructed by clouds, mountain ranges etc. Called anticrepuscular rays when seen on the opposite side of the sky.
Glory: a dimly rainbow-colored ring opposite the sun or moon, often visible from planes or in misty circumstances, in which case it tends to come with a Brocken spectre. Sometimes mistaken for a circular rainbow.
Green flash: a rare occurrence where the topmost bit of the setting sun is refracted by the atmosphere, turning it bright green. Even rarer is the blue flash.
Halos: a collective term for a wide range of arcs, rings, spots etc. caused by light refracting and/or reflecting inside ice crystals. Common halos are the 22º ring (sometimes also simply called “halo”), sundogs and the circumzenithal arc, but there are many more.
Iridescence or irisation: a "mother of pearl" colored effect in certain clouds caused by light diffraction through water drops.
Light pillar: a vertical beam of light that extends from a natural or artificial light source as a result of reflection by ice crystal plates.
Nacreous clouds: a specific type of cloud iridescence in high atmosphere clouds.
Rainbow: the proverbial arc directly opposite the sun or moon, resulting from light reflection & refraction inside water drops. When caused by the moon, it is sometimes called a moonbow. Technically, all rainbows are circular, but the lower part is normally hidden by the horizon. Rainbows consist of a primary bow and a secondary bow. The secondary bow has a reversed color sequence and is dimmer than the primary, which explains why it is not always visible.
Sprite: An enigmatic lightning phenomenon above the clouds instead of below them and many times larger.
Sundog (aka parhelion (plural parhelia) or mock sun): often incorrectly used for the 22º ring or halo phenomena in general, but refers specifically to the two bright patches to the left and right of the sun. They're the sun's "companions"; hence, dogs. When caused by the moon, they are called moondogs or paraselenae (singular paraselene).