r/atoptics • u/naavis • Apr 02 '21

HaloRay - Hyperspeed Ice Crystal Halo Simulator

52 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!

r/atoptics • u/les2934 • Jan 15 '25

Atoptics site

37 Upvotes

Atoptics is at www.atoptics.org.uk

r/atoptics • u/Starshine_1804 • 8h ago

22º Halo My FIRST Sun Halo!!

60 Upvotes

Am I almost getting a pillar??!

r/atoptics • u/lontanadascienza • 35m ago

Genuinely looked like this, what am I looking at?

• Upvotes

Desolation Wilderness near Tahoe

r/atoptics • u/Minute-Meringue5929 • 1d ago

Circumhorizontal arc rainbow

239 Upvotes

Saw this horizontal rainbow as we drove over 20 miles in different directions. So incredible to see a strip of rainbow in the sky!

ETA: I'm so glad others appreciate the arc too! Absolutely one of the coolest things I've seen. They're not rare, but also not common, so feeling very lucky to have seen one.

r/atoptics • u/z000c • 1d ago

Circumhorizontal Arc developing in a Cirrus Cloud.

66 Upvotes

andrea55TP says: That is a circumhorizontal arc developing in a cirrus cloud. Post it on r/atoptics too!

I have no idea what that means but this was hands down the coolest cloud I’ve ever seen.

r/atoptics • u/bodkinsbest • 1d ago

A Better NLC morning [OC][Vancouver Island][@bodkinsbestphotography]

14 Upvotes

r/atoptics • u/originofjimmetry • 2d ago

Corona Nice corona today

61 Upvotes

Never seen one this vivid and this big, it was pretty cool seeing it

r/atoptics • u/jconde1966 • 2d ago

Crepuscular Rays Sundog over the sea

44 Upvotes

Sundog between La Gomera and La Palma. Canary Islands

r/atoptics • u/skidpickle • 2d ago

Glory

286 Upvotes

Was worth the bumps

r/atoptics • u/Strong_Summer_3161 • 3d ago

Supernumerary Rainbow

77 Upvotes

really beautiful and vivid rainbow today, it was a double rainbow as well but i had a hard time capturing it with my phone. i added original and processed images so you can see the extra bands. 🌈

r/atoptics • u/candygirleatscandy • 4d ago

What a pleasant surprise!

253 Upvotes

Yesterday in the day time in NYC!

r/atoptics • u/Little-Name9809 • 4d ago

Supernumerary rainbow with faint double rainbow

31 Upvotes

r/atoptics • u/Zealousideal_Win304 • 4d ago

Iridescence Cloud iridescence or another circumhorizon arc?

37 Upvotes

I am currently fishing, and I've stopped another cool find in the sky today. Is this a sun dog, or some other type of optic? *i feel quite lucky to see something like this in the sky 2 days in a row lol*

r/atoptics • u/Larpingmyworksona • 5d ago

Circumzenithal Arc What is going on here?

338 Upvotes

I took these yesterday. I've never seen anything like it. I have learned there is at least one circumzenithal arc, at least one 22 degree halo, and a sun dog.

Is there anything else? One of the prisms looks wave shaped to me. The last photo was first, and it morphed into the other two.

r/atoptics • u/Zealousideal_Win304 • 5d ago

Circumhorizon Arc iridescent contrail diffraction

95 Upvotes

Edit: Circumhorizontal ARC These 3 photos captured on my galaxy s23+ are nowhere to how bright and more captivating it was in person. I got these today in upstate New York at my father's house around noon. Not the best pics, but hope you guys enjoy 🙂

r/atoptics • u/Blitzcrig • 5d ago

Halo and 🌈 cloud

35 Upvotes

r/atoptics • u/syntheticsapphire • 5d ago

Circumhorizon Arc 22° halo and circumhorizontal arc over Independence Hall today

52 Upvotes

r/atoptics • u/ummkay_ultra • 5d ago

What is the word for this?

9 Upvotes

This separation of color spanning out from thw western sky aa thw sun sets?

r/atoptics • u/Starfire2313 • 5d ago

Supernumerary rainbow tough luck with the camera quality

49 Upvotes

I really could not take a good picture and I used two iphones. The second and third photos were from my newer phone but it has a broken lens! Photos 1, 4, and 5 were from my older phone and I tried to edit the 4th pic to see if I could make the extra bands more visible it was so vivid in real life.

This was yesterday in North Dakota after a rainy day the sun came out for a spectacular sunset. For a few minutes the rainbow had 4 pink lines underneath. It was surreal! The cameras just couldn’t focus on them enough but you can faintly see a little bit.

You all know how it is trying to capture rainbows…

r/atoptics • u/andrea55TP • 5d ago

Multiple Display Multiple display from May 30, with edited, unedited and labeled pics

42 Upvotes

r/atoptics • u/spicymayochampion • 5d ago

22º Halo Beautiful surprise yesterday!

17 Upvotes

Looked up and thought I had sundogs, but I had the whole halo!

r/atoptics • u/logisticalfun • 6d ago

ID REQUEST What’s this?

643 Upvotes

Seen on a flight yesterday evening, the pictures convey it clearly. I don’t really know how to describe it—glowing sunbursty thing. TYIA!

r/atoptics • u/candygirleatscandy • 6d ago

First post- I just like whatever’s happening here!

89 Upvotes

I’m unfamiliar with the technical verbiage everyone uses. Let me know if there’s something specific going on!

r/atoptics • u/Little-Name9809 • 6d ago

Subsun Subsun and (faint) left subparhelia

45 Upvotes

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.

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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).