Exoplanet Explorer HD: Interstellar space
Work has continued on the new Exoplanet Explorer HD, albeit at a slower pace. It’s the last 10% of a project that takes 90% of the time.
Most of my effort has been involved working out a method to smoothly transition between the interstellar galaxy view (as seen in Galaxy Explorer) and the system view.
It’s difficult to explain, but the issue is mainly the gaps between star systems. The volume of space encompassed by Exoplanet Explorer is thousands of light years across. Within that space some of the stars are quite close together, particularly binary systems. The floating point math used to position objects within the virtual world doesn’t have the accuracy to handle values that range from thousands of kilometres (planets) to thousands of lightyears (interstellar space). I had to try several different idea before I came up with a method for smoothly swapping between the interstellar and solar system views. It was a time consuming task, but it’s done now and what’s more, it looks great.
The next step is to figure out how to transition from the system view, to the planet view where you can fly around in the system like you are in a spaceship. This is actually going to be a lot easier than the interstellar transition, so I don’t expect it to take too long.
Besides that, I have now finished all of the screens in the app, though testing is needed.
I’ve discovered that a significant percentage of the planets listed in the PHL database don’t include a distance for the star. Over half were in fact missing this value, which meant that they couldn’t be rendered by the app. To get around this, I’ve compiled a database of basic star information that can be used to lookup what’s missing in the PHL data. If the import procedure detects that a star’s direction or distance is missing, then it’ll use the built in value, assuming it can find a match. There is the issue that there are lots of different catalogs, so there are variety of different names for some stars.
As mentioned, the first release of the new Exoplanet Explorer HD app won’t include binary systems. This is because the PHL database assumes that every planet has only one star, so it doesn’t include any information about star relationships. The Open Exoplanet Catalog does include binary systems, but it doesn’t have the PHL’s habitability information. The long term plan is to come up with a method for importing both databases so that they can be used to render binary systems.
I’m hoping that Exoplanet Explorer HD will be completed in the next week or so.