[HN Gopher] Show HN: GPX replay map that shows terrain shadows d...
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Show HN: GPX replay map that shows terrain shadows during
activities
Author : tppiotrowski
Score : 35 points
Date : 2021-10-13 17:28 UTC (5 hours ago)
(HTM) web link (shademap.app)
(TXT) w3m dump (shademap.app)
| carabiner wrote:
| Where do you get the terrain elevation data? What resolution is
| it? I've been looking for good elevation data for another
| project.
| tppiotrowski wrote:
| Nextzen has freely available DEM tile data to zoom level 15, so
| about 5 meters/pixel. You need a free API key [1]
|
| Mapbox has paid DEM data to zoom level 20, but I think it's
| just zoom level 15 scaled up (but the data is cleaner and more
| recent) [2]
|
| Nextzen also open-sourced their elevation tile generator, but I
| haven't tried to generate my own tiles [3]
|
| [1] https://www.nextzen.org/#terrain-tiles
|
| [2] https://docs.mapbox.com/help/troubleshooting/access-
| elevatio...
|
| [3] https://github.com/tilezen/joerd
| _Microft wrote:
| Make sure to draw the slider far enough to see the effect. The
| map has a grey overlay (time is before sunrise?) for the first
| 10% or so of the track.
| tppiotrowski wrote:
| Good suggestion. I need to improve the UX. And you are correct,
| the grey overlay is night time.
| alanbernstein wrote:
| Really neat project.
|
| Relevant to the parent suggestion, you might add some
| indicators on the slider to show where daytime is.
| dddw wrote:
| I was waiting for it to animate. Maybe a play button would be
| nice. Real cool though.
| tppiotrowski wrote:
| Thank you. Autoplay would be amazing to prevent bounces from
| users that don't immediately know what the slider does but I'm
| a bit worried I will tax the GPU on low-end devices or large
| screens and end up freezing the page. Before I can introduce a
| play button I need to understand how to profile GPU performance
| and change the quality to maintain a healthy frame rate.
| Scaevolus wrote:
| Huh, I didn't realize that a summer sun in the northern
| hemisphere rises from ENE.
| https://www.suncalc.org/#/43.7434,-110.7355,12/2021.07.17/12...
|
| Incorporating some of the overall sky colors might be neat, so
| that twilight looks different than midnight.
| tppiotrowski wrote:
| There was a recent discussion about this on HN:
| https://news.ycombinator.com/item?id=28420835
| tppiotrowski wrote:
| I've always had a hard time visualising the passage of time when
| viewing my GPX tracks. I wanted a better way to relive the moment
| and stimulate memories of what the day was like, so I put
| together this little visualisation that works with any .gpx
| track[1].
|
| [1] .gpx track must have timestamps
| 28mm wrote:
| This would be really interesting as a planning tool. Have you
| thought about making the start time selectable?
| tppiotrowski wrote:
| GPX replay is a proof-of-concept built on an API and map
| plugins I've been developing over the past year.
|
| There are more features like the ability to view shade for any
| time/date/location throughout the year, search, building
| shadows, and high DPI mode available at the base url:
| https://shademap.app
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(page generated 2021-10-13 23:01 UTC)