
Show HN: Data-viz project for ray-tracing the Moon model - ray_gray
https://github.com/rnd-team-dev/plotoptix/tree/master/examples/3_projects/moon
======
ray_gray
Ray-tracing is done in a Python notebook. Data originates from NASA public
resources. I searched for the highest resolution data to make the Moon almost
touchable. So it is made of 118m elevetion model and 480m surface color. There
is also 59m elevation model, but this 22GB does not really fit into my
laptop's GPU.

Code can run on GCP instance. Laptop/desktop is more convenient, though.

If you'd like to go straight to pictures:
[https://www.behance.net/gallery/84326717/Making-of-the-
Moon](https://www.behance.net/gallery/84326717/Making-of-the-Moon)

or tutorial: [https://medium.com/@sulej.robert/the-moon-made-twice-at-
home...](https://medium.com/@sulej.robert/the-moon-made-twice-at-
home-a2cb73b3f1e8)

~~~
jszymborski
pretty photos, and nice work!

more than anything, though, thanks for introducing me to PlotOptiX! It looks
like a great way to plot scientific data in 3D :D

------
ray_gray
Thanks to all for the feedback and comments!

@rcarmo Yes, bumps are enhanced, to make the surface more dramatic. This scale
is a parameter in the notebook, it can be set to the realistic 1.15% of the
mean radius.

On another forum, someone pointed out that the Lambertian shading makes the
Moon surface too smooth. So the diffuse material roughness will come in the
next PlotOptiX release, in a few days. :)

------
ReD_CoDE
Maybe this help with:
[https://github.com/x3dom/x3dom](https://github.com/x3dom/x3dom)

As I heard it's based on explicit DOMs.

Have anyone tried X3DOM?

------
rcarmo
The video is very nice, although the bump/displacement seems a little too
strong - craters should look a little shallower :)

~~~
Zelizz
The Medium article says that was intentional:

> That gives the elevation spread of about 1.15% of the mean radius. I’ll use
> a bit higher value of 2%, so the terrain features are more prominent.

~~~
rcarmo
I missed that bit, thanks!

------
dvh
Do you use Lola data? What resolution and from where?

~~~
ray_gray
Yes, 118m resolution, it is from:
[https://astrogeology.usgs.gov/search/details/Moon/LRO/LOLA/L...](https://astrogeology.usgs.gov/search/details/Moon/LRO/LOLA/Lunar_LRO_LOLA_Global_LDEM_118m_Mar2014/cub)

All other sources (surface color, star map in the background) are referenced
in notebooks, gallery, and tutorial as well.

------
pplonski86
What hardware did you use to produce such photos?

~~~
ray_gray
PlotOptiX requires NVIDIA GPU. I used GTX1060/6GB on a laptop for most of the
work. Tested also on a desktop RTX1070/8GB, much better fps, of course. Video
is done on RTX. In Google Cloud, on V100, runs even faster, but GUI is more
convenient on local machine.

