Moon Mesh Maker

Installation

After cloning this repo into a folder, run the following command to install the Python dependencies:

pip3 install -r requirements.txt

To compile the C++ components, ensure that the gdal, cxxopts, and libtiff libraries are installed. Then go into the cpp directory and run the following commands:

mkdir build
cd build
cmake ..
make

Source Data

For my videos, I started with the DEM and diffuse data from NASA's Goddard Space Flight Center's Scientific Visualization Studio's CGI Moon kit at https://svs.gsfc.nasa.gov/4720.

Later, I stitched DTM data from the LROC accessible at https://wms.lroc.asu.edu/lroc/view_rdr/WAC_GLD100.

I use JOL's planetary ephemeris from https://ssd.jpl.nasa.gov/ftp/eph/planets/bsp/.

Due to large file sizes, none of the source data is included in this repo. You will need to download the data yourself.

Limitations

The source textures must be cylindrical projections centered at (0,0). The output meshes also assume the Moon is a sphere. If you try to use data from non-spherical bodies, the mesh will not be accurate.

Usage

First, you will need to generate a mesh from the DEM. To do this, run ./cpp/build/MoonSurface with the following arguments:

A program to generate a moon surface
Usage:
  MoonSurface [OPTION...]

      --centerlat arg         Center Latitude
      --centerlon arg         Center Longitude
      --latextent arg         Latitude Width
      --lonextent arg         Longitude Height
      --verts-per-degree arg  Vertices Per Degree
      --scale arg             Scale (default: 1.0)
      --threads arg           Number of threads (default: 1)
      --rotate-flat           Transform mesh so the center latlon is facing 
                              z-up
      --dem-path arg          Path to DEM file. Can be used multiple times 
                              to load multiple DEM files.
      --output arg            Output file title (default: moonmesh)
  -h, --help                  Print help

Next, run python moonsurface.py with the following arguments to generate a .pkl file containing the sun position and image texture

usage: moonsurface.py [-h] --latlon LATLON LATLON --angular-extents ANGULAR_EXTENTS ANGULAR_EXTENTS --img-path IMG_PATH [--output OUTPUT] [--rotate-flat] [--date DATE]
                      [--time TIME] [--ephemeris-path EPHEMERIS_PATH]

Create a mesh from a DEM

options:
  -h, --help            show this help message and exit
  --latlon LATLON LATLON
                        The latitude and longitude of the center of the mesh
  --angular-extents ANGULAR_EXTENTS ANGULAR_EXTENTS
                        The angular extents of the mesh in degrees
  --img-path IMG_PATH   The path to the diffuse texture image
  --output OUTPUT       The base of output filenames. The mesh will be saved as <output>.pkl and the texture will be saved as <output>.TIF. Defaults to moon_mesh
  --rotate-flat         Places mesh's center at the origin and rotates the mesh so the center points in the positive z direction. Defaults to False
  --date DATE           The UTC date to use for the sun angle. Must be YYYY-MM-DD
  --time TIME           The UTC time to use for the sun angle. Must be HH:MM:SS
  --ephemeris-path EPHEMERIS_PATH
                        The path to the ephemeris file.

After creating the file, create a Blender file and save it in the same directory as the repo. In the Scripting tab, open the load_moon.py script. If you used a different output name, change the MESH_NAME variable so it is the same as the one you used. Then, you can run the script to load the generated mesh into Blender.

License

This project is licensed under the MIT License. See the license file for details.

Credits

CGI Moon Kit

NASA's Scientific Visualization Studio

Visualizer: Ernie Wright (USRA) [Lead]
Scientist: Noah Petro (NASA/GSFC)

LROC Raw DTMs

Scholten, F., Oberst, J., Matz, K. D., Roatsch, T., Wählisch, M., Speyerer, E. J., & Robinson, M. S. (2012). GLD100: The near-global lunar 100 m raster DTM from LROC WAC stereo image data. Journal of Geophysical Research: Planets, 117(E12). https://dx.doi.org/10.1029/2011JE003926

Smith, D. E., Zuber, M. T., Neumann, G. A., Lemoine, F. G., Mazarico, E., Torrence, M. H., McGarrey, J. F., Rowlands, D. D., Head, J. W., Duxbury, T. H., Aharonson, O., Lucey, P. G., Robinson, M. S., Barnouin, O. S., Cavanaugh, J. F., Sun, X., Liiva, P., Mao, D., Smith, J.C., & Bartels, A. E. (2010). Initial observations from the lunar orbiter laser altimeter (LOLA). Geophysical Research Letters, 37(18). https://dx.doi.org/10.1029/2010GL043751

ordelore / moon-maker