Archive

This project was undertaken during the fall of 2021, during a graduate Software Development class at the University of Alaska Fairbanks.

As the class is over and this project has not been maintained in several years, it is being archived.

Aurora

Decompressing the Textures

Run tar zxvf textures.tar.gz at the top level of the repository to un-gzip and un-tar the textures tarball - this should automatically put all the textures where they need to go.

Build EPR

This project requires the following:

• GCC
• make

A typical linux install would be: sudo apt install gcc make

A windows install can be done, but it is recommended that you install using WSL and follow the linux instructions.

Start by cloning this project:

• git clone git@github.com:dgpalmieri/aurora.git

Build Dependencies:

• cd aurora\EPR\Library
• make clean libepr.a
• cd ..
• make clean epr
• cd ../Code
• make sp2ppm

Move sp2ppm to bin, make sure your .local/bin is in $PATH.

• mv sp2ppm /home/$USER/.local/bin

You can check that this is working by running which sp2ppm which should return: /home/$USER/.local/bin/sp2ppm

Rendering

Once the system is build you can now render your first images. The script tacc1 provides a simple 1 frame render.

cd Aurora/EPR

tacc1 will produce a single frame from 7400 to 7400 by steps of size 1. below is the name of outfile, and -res provides pixel resolution. You must provide a square resolution to render the fisheye.

tacc1 also uses the cam.se59 camera path, and uses the se59_08K configuration file.

./epr.gre se59_08K cam.se59 -range 7400 7400 1 below -res 4096 4096

Example Render

To render frames 6500 to 7500 with step size 10 on the cam.se59 path using the se59_04k config with 1920x1920 res. The command would be ./epr.gre se59_08K cam.se59 -range 6500 7500 10 below -res 1920 1920 Once the command finishes, there will be several below_{frame number}.green files.

Converting to PPM

The sp2ppm utility is used to generate ppm from the energy levels created by epr. There is a helper script that is included to generate the ppm images. The script provided to generate *.ppm for each frame is conv_raw.

The script will step through the current directory matching all files that are named below_{frame_id}.green and generating a matching below_{frame_id}.ppm file that is the image.

The single file command is as follows:

• sp2ppm $b $b.ppm 0.0 600.0 0.0 400.0 0.0 400.0

Where b is the file name without the .green extension.

Example Conversion

To swap a single file to .ppm the command is as follows: I would like to render below_06500.green to below_06500.ppm

• sp2ppm below_06500 below_06500.ppm 0.0 600.0 0.0 400.0 0.0 400.0

The parameters are tuning of energy levels to color. There are examples of other color mappings in the conv_raw script.

Opening PPM

To open the *.ppm, you can use Inkscape, Irfanview, or imv.

Making a video

FFMPEG

ffmpeg is a free way to make a ppm into a video. Install with sudo apt install ffmpeg

To render a sequence into a video you can use the following command: ffmpeg -pattern_type glob -s 1920x1920 -framerate 25 -i "*.ppm" output_vid.avi

This will grab all ppm files in the directory, set framerate to 25 and the scale at 1920x1920. The output file will be output_vid.avi, feel free to mess around with these as you make different changes to renders.