[HN Gopher] Show HN: Google Maps Shadow Calculator
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       Show HN: Google Maps Shadow Calculator
        
       Author : gdaramouskas
       Score  : 102 points
       Date   : 2022-03-11 12:49 UTC (10 hours ago)
        
 (HTM) web link (shadowcalculator.eu)
 (TXT) w3m dump (shadowcalculator.eu)
        
       | ricardo81 wrote:
       | Very nice. Confirms that installing solar panels on my roof
       | simply isn't economical.
       | 
       | Guess installers would find something like this handy.
        
       | ldayley wrote:
       | 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/
        
       | pcthrowaway wrote:
       | 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
        
       | cyborgx7 wrote:
       | 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.
        
         | alfanick wrote:
         | Yup, seems to treat Earth as flat, not really useful in my area
         | (living in the valley, surrounded by high mountains from east
         | and west - sunrise time does not mean you're going to see sun,
         | if it's still hiding behind a mountain).
        
         | cpp_frog wrote:
         | Assumes a flat surface, I've just tested it on a large crater
         | [0].
         | 
         | [0]
         | http://shadowcalculator.eu/#/lat/-23.928141910247348/lng/-68...
        
       | folli wrote:
       | 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
        
         | jihadjihad wrote:
         | I've got to say, as someone who lives nowhere near a city as
         | big as NY, the view of the shadows that are cast upon Central
         | Park throughout the day is simply mind blowing.
        
       | a3_nm wrote:
       | 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.
        
         | [deleted]
        
         | [deleted]
        
         | tppiotrowski wrote:
         | I made a tool for this. Check out
         | https://shademap.app/@37.72457,-119.60944,10.69315z,16470110...
        
           | folli wrote:
           | Big fan of your app (I even mention it in the thread, didn't
           | see your comment): but what happened to the 3D view?
        
       | compsciphd wrote:
       | 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.
        
       | victormier wrote:
       | good job! would be great if you could add polygon params and
       | datetimes in the url so it would be easier to share
        
       | weichbild wrote:
       | 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!
        
       | pmlamotte wrote:
       | 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.
        
         | tppiotrowski wrote:
         | One like this exists for Barcelona:
         | https://www2.bcnregional.com/
        
       | cpp_frog wrote:
       | 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...
        
       | dsmmcken wrote:
       | 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!
        
       | seba_dos1 wrote:
       | The title is kinda misleading, as this has nothing to do with
       | Google Maps other than using it as a map source.
        
       | Snoozus wrote:
       | 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?
        
         | juki wrote:
         | > Could this be used to generate large scale 3d building models
         | automatically?
         | 
         | A lot of places have lidar data available that can be used for
         | that.
        
       | monkeydust wrote:
       | 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.
        
         | alias_neo wrote:
         | Could I use this to figure out what I might he able to achieve
         | from adding solar to my home if I hooked it up to
         | homeassistant?
         | 
         | I'm in the UK and trying to work out if it's worth it with our
         | subjectively poor sunlight.
        
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       (page generated 2022-03-11 23:01 UTC)