Ship
Final devlog for now, finished map view and added camera information
I have added camera controls where you can change to view a planet from its own axis or rotation by pressing (c) to cycle through modes, and you can track objects by pressing (t). Also added more information on the ground view, light time calculation and finally the map view where once opened you can change your position by clicking on it.
Finished all the continents, added saturns rings and and Mars and Jupiter’s moons.
I have made decent progress, most of my time was spent debugging and optimizing since I’m only using the cpu to render everything.
I also added more camera controls so that when you press (c) you can tilt the camera to match the planets axis tilt, or rotate along with it.
The final parts I need to add at this point is a menu where you can choose your location and a information panel for the object that you select.
Added continent outlines and object occlusion
After spending way too much time trying to figure out webgl and three.js I decided that it was not worth the extra effort for slightly better graphics. Running out of time, I decided to stick to the system that I already had and decided to just draw the coastlines so you can make out the earths orientation better. Right now I have only added N&S America, Antarctica, and Australia. Ill add the rest later but for now this is what I got. Running out of time to ship this so I’m going to add a location selector and call this good.
Added ground perspective and fixed stars
Added a feature where you can select a position on the earth and view from there. You do have to manually add your latitude and longitude but eventually you will be able to select from a map or search for a specific city. (The demo shows London UK’s position so I don’t reveal my own)
I also fixed the lag from the stars that was making the site slow, now it can display 3500 stars and all the other objects just fine.
General Relativity Renderer
This is my first devlog on my project where I am writing a program that renders different objects described by general relativity. I have experience doing this stuff before (though in scratch, not the best programming language for ease of use) so I decided to do this again in python. After for the last time realizing how slow python is(the attached image took ~11hrs to render with the current program) I’m deciding to try with another programming language. My current plan is to try webgl and gain experience using shaders, because every past method I use has not used the GPU to its full extent.
After all of this I still want this to be as accurate as possible, sticking to the math as best I can.
Objects I plan to simulate:
- Regular empty spacetime(relativistic effects)
- Schwarzschild Black Hole
- Kerr Black Hole
- Binary Black Holes (heuristic)
- wormhole
- Potentially any metric you can design with any set of coordinates
Added grid based on your location, and stars from the Henry Draper (HD) catalogue. https://in-the-sky.org/data/catalogue.php?cat=HD&const=1&sort=1&view=1&page=1 Unfortunately now the framerate has dropped a lot, so I’ll need to figure out how to handle all the objects separately and only update the planets. Until then that’s enough programming for me today.
Added TLE support https://en.wikipedia.org/wiki/Two-line_element_set (A common file format for earth orbit satellites). I’ve realized that I might have to switch to using a graphics api like webgl to improve the graphics from here, but for now I will focus on functionality. Better graphics should not matter at the moment from a ground level perspective.
Finally added a way to read separate files into the web app. Objects are now stored in json files with all their orbital parameters and physical characteristics. Next steps for this project will be to start adding detail on the planets and reference frame transformations from your local position to space.
You can now click on objects to select them. Orbits now also accurately precess. The moon’s orbit is now close enough to reality to predict solar eclipses, which is accurate enough for this project. All the inner rocky planet’s procession has been implemented as well according to NASA horizon’s approximation. They should now be reasonably accurate a few hundred yrs into the future. Next steps will be adding more objects like Jovian moons and spacecraft, as well as improving graphics.
Added the main 8 planets in the solar system and a time control feature. You can now speed up, slow down, or reverse time to see the solar system on different dates, or reset to the current time. You can also scroll through the list of planets and watch from their perspective. As far as I can tell I succeeded in making the planets positions accurate (or at least enough for my project).
Added functionality for objects to orbit other objects. Progress is coming along nicely so far, all orbits of type e<1 are displayable and can be centered around any object. The next steps I plan on taking are plugging in the values for our actual solar system and switching camera controls to be centered on planets, then adding time control and other UI.
I added mouse controls, Kepler’s 2nd law, and a grid that will come in handy for identifying places in the sky. Next I will continue to add features for adding celestial bodies and different spacecraft.
Added orbit calculations to the planetarium web app so I can start adding other objects in the display.
A few more functions will need to be implemented but very soon I should be able to start plugging in data.
Starting the basic foundation of the web app, I plan on using only JavaScript and HTML5’s canvas to draw all the objects, using data from celestrack and NASA horizons to find all the data I need. Screenshot is just of a test of the basic 3d drawing function with axis visible. Because it is just night sky objects no fancy 3d engine will be needed.
