Show HN: Google Maps Shadow Calculator

Awesome work! I'm using it to figure out the shadows cast by the Twin Towers (417 m. and 415 m., North and South towers, respectively) at different times of the day and different dates. They were truly gargantuan buildings.

http://shadowcalculator.eu/#/lat/40.71136008109719/lng/-74.0...

As an outdoor photographer I’m constantly referring to an ephemeris[0] to check out the light situation at different times. This isn’t nearly as full featured as what I use but I love the idea of hacking something like this together with common APIs for a quick and dirty approximation.

Interesting work. Thank you.

[0]: https://app.photoephemeris.com/

I personally find http://shademap.app much nicer.

And obligatory plug for my Android App (if you need an Augmented Reality type of application to visualize the sun position): http://sunlocator.com

Very cool. Sorry for being "that guy" but I assume this doesn't take into account the earth surface curvature, just the relative sun position and then assumes a flat earth?

It probably not nearly significant enough on the scale of the use case described on the site, but a shadow on a sphere has a different shape than a shadow on a plane. Though that effect may cancel out depending on the map projection that was used.

Very neat! An idea that often came up amongst coworkers while walking to a lunch spot during the hot summers was being able to get walking directions that preferred routes in shadow. We had our own routes we came up with that didn't add much time to the total trip but had a massive increase in shade versus almost none on the fastest route.

This reminds me a lot of that, though you would need good data on building heights and shapes as well as which side of the sidewalk you would walk on (if walking on both is even possible). Would love to see that get created some day.

I actually proposed something similiar to friends at google maps, that it be interesting for walking directions to advise based on which route would be most shadowed (say in the hot summer in a non humid climate where there's a huge difference between shadowed and non shadowed paths in terms of comfort.

Wow, this is going to be great for determining ideal time of day to climb at different areas

edit: the controls really could use some work though

edit2: It doesn't appear to take elevation data into account, which might be useful. More to the point, it doesn't take shadows from surrounding terrain into account

Nice work.

If your interested in using this for evaluating solar production then check out https://solcast.com/

There is a free version. I have it hooked this up to Homeassistant and predicting output for my home solar rig.

Ah this is perfectly timed--many of the old garden-focused azimuth / altitude / persephone day calculators are defunct and never handled the problem of cast shadows very well in the first place. Nice work!

The drag handles are a bit finicky/small to grab, and would be nice to be able to set the heights as a group. Otherwise great!

Very nice. Confirms that installing solar panels on my roof simply isn't economical.

Guess installers would find something like this handy.

good job! would be great if you could add polygon params and datetimes in the url so it would be easier to share

so knowing the buliding height we could figure out which time and day the aerial picture was taken? And given time and day we could figure out how high the buildings are. Could this be used to generate large scale 3d building models automatically? Does anyone know whether this has been attempted?

The title is kinda misleading, as this has nothing to do with Google Maps other than using it as a map source.

I thought this could solve the following problem: when camping during a mountain hike, figure out where to set up the tent, by knowing at which time you will be woken up by sunlight. Unfortunately this app doesn't seem to take elevation into account -- I don't know if there is some other tool that can do it.