Neat!

Annoyingly it seems every time you scroll pass one of the maps a browser history entry is pushed

They always keep 2 iframes loaded; when you scroll down (or up) the old iframes are unloaded by setting their src="" and the new ones are loaded by setting their src attribute to the correct URL (kept the "source" attribute of the iframe).

However, when you change the src attribute of an iframe, for some reason your browser creates a new history frame. I suppose so you can navigate inside of an iframe and go back/forward as expected.

The correct solution is to create/remove the entire iframe element instead of reassigning the src attribute.

See discussion at http://stackoverflow.com/questions/14737365/modify-iframe-sr...

You can see it in the HTML source of the page around the "check visibility every half-second, hide off-screen demos to go easy on the GPU" comment.

oh the humanity

Super awesome writeup and use of leaflet, very pretty maps! I work for a drone company and we deal with DEM data all the time, I recognized your first image of the clamped PNG.

Here's one of our office: http://kespry-experiments.s3.amazonaws.com/elevation/valueFo...

The author keeps referring to "Gak", with which I'm unfamiliar. Is it this? https://en.wikipedia.org/wiki/Nickelodeon_Toys#Gak Is it just because of the color?

Yes, it's most certainly that. See also http://knowyourmeme.com/memes/events/gak

But also the freeform sprawling shape that Gak was packaged in: https://i.ytimg.com/vi/MSDVImHZsFU/hqdefault.jpg

I'm really glad someone is producing a service like this and will start using it as soon as coverage is at least national!

I wrote a webapp hillmap.com that does client side slope shading for travel in avalanche terrain a few years ago using a usgs webservice that has since broken. I've looked into building a replacement but it is amazing how hard it is to find consistent elevation data across the globe.

That's cool. It's amazing how much overlap there is with gamedev concepts.

It'd be cool if there were more maps you could play with on their site.

Back button breaks (Firefox).

From the article: "Fly with me now, on a tour through the world of elevation data"

Basically a nice article talking about how the data is gathered, stored, and sometimes used.

The article has nothing to do with how the data is gathered, stored and sometimes used. It's about real-time rendering of elevation maps in the browser. It's really impressive work.

How does a comment like this happen? Looking at your history, it looks like it's your habit to provide a short sumary of articles. That's helpful to people, but... only if you actually read the article.

Is this a good way to farm karma or something?