Show HN: A raytracer to shade topographic maps in R, Part 2

I share your awe at the Vatican map gallery. Two stories high, floor to ceiling, 400 hundred year old hand painted maps, for the entire length of a football field. And it’s not just the size, it’s the detail and joy put into maps of little places that no one outside has ever heard of.

I’ve never found photos online that half show how awesome the map gallery is. If I ever get back to the Vatican, I plan on spending 90 of my time there.

If you have a thing for Lake Mead then you really need to read the Edward Abbey books Desert Solitaire and The Monkey Wrench Gang. Very beautiful part of the world and I am glad to see you have a passion for getting the maps right.

Are you aware of the work that has been done with shaders to trace through depth maps in real time?

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.138...

This shows relaxed cone mapping, which is a very elegant and effective optimization.

GDAL does has hillshading routines (gdaldem hillshade), but it does not have the raytracing, spherical UV shading, or ambient occlusion layers included in rayshader. It's hillshading routine is basically the rayshader's lamb_shade function--functional, but not going to win any beauty contests.

GRASS does have a raytracing option, but if you look up the images produced by it--they aren't pretty. Much more of a functional API to see where actual shadows are falling, and not at all something to produce nice looking maps.

The real killer feature in rayshader is the seamless API for combining all of these layers. Being able to adjust the intensity of each layer individual, add water, change color and texture programmatically--no other software focuses nearly as much on the aesthetics of a great looking map.

I haven't found anything other than actual 3D modeling software that can produce similar-style hillshades--combining texturing, raytracing, local shadows, and ambient occlusion. What's great (in my highly biased opinion!) about this package is the ability to go programmatically straight from the DEM to a hillshade, without having to save the data and load it into Blender or something similar.

Because that would be cheating. ;) People like to create things from scratch.

Also, I like that quote: > Ask the internet how to do something and you’re likely to get a bunch of digital shrugs and maybe—if you’re lucky—a passive aggressive link to a Wikipedia page. Tell the internet you’ve done something—and they’ll tell you exactly what you can do to improve it.

You can certainly throw something into actual 3D rendering software and get something similar--if you know how to use it! That's the point. This is a way to go straight from DEM to beautiful map, without having to teach yourself Blender or open any external program. You can go straight from matrix to map in just a few lines of code--and adjusting each layer to match the aesthetic you're after is easy.

Everything here is produced and adjustable programmatically: need to change the highlight color in the texture? Just use the create_texture function with the colors. Want to tone down raytraced shadows? Decrease the max_darken value in add_shadow. Rotate the sun direction or the color of the water? It's all straightforward. This library is designed to be as seamless and flexible as possible, so you never have to leave R to produce a nice looking map.