Following the live stream, Dr Ant Ross answered some questions. You can see them below, on the official forum here, or on Reddit, here.
1) Is “The Bulge” what is referred to in game as The Bubble?
The galactic bulge, or galactic core, is the blob shaped region of stars in the centre of the Milky Way. It is a separate thing from The Bubble, which is the region of human inhabited space around Sol.
2) Why did Elite Dangerous decide to use light-years and not parsecs in-game?
I don’t believe there was a specific reason why. The original Elite and its sequels also used light years for interstellar distances, and it is nice to be consistent.
3) Does the game allow for any catastrophes? Novae, rogue-planet ejection or capture, system collision?
During the generation stage, rogue-planet events and collisions are taken into account. However, these are historical and not visual effects. When you arrive in the system, you only see the results of those effects on the resulting stable system.
4) When do we get to hear about what is coming next for Stellar Forge? Like comets, flyable gas giants, etc.
Oh, yeah, that’s scheduled for MMPPPPPPH ( Ant gets dragged away by Zac ). Ahem, hm, apologies, but I can’t really talk about that at the moment.
5) Why does Elite Dangerous only use circular orbits? Are elliptical orbits too complicated?
Elite Dangerous does use elliptical orbits. The inclination, periapsis, longitude of ascending node, semi major axis and eccentricity information is all tracked.
6) There are some planets in the game that look like they would be torn apart by tidal forces. Did you say you actually simulate this? What means those close planets are actually possible?
There are some bodies which may be near the mathematical limit of that collection of matter being clumped together. However, we don’t currently have the rendering feature to display what the surfaces of those look like or how you would interact with them. In reality, you may see a distorted molten mess.
7) The in-system barycentre-orbital distribution in the game is quite vast, given the limited observed bodies (just Pluto/Charon). Is that likely true to life?
The distant orbits which are created should follow Kepler’s laws of planetary motion and classical (non-relativistic) orbital calculations. The resulting hierarchies of orbits should be feasible, but it will be very interesting to see what comes from the future of orbital mechanics analyses and exo-planet searches.
8) Is there anything orbiting within Lagrange Points at all in Elite?
There is a section of code running capture interactions in the virtual protoplanetary disk which can place bodies into the L4 and L5 Lagrange points. I believe this ends up being mostly asteroid clusters, but I have not had a look at them in a while.
9) Have you ever forgot the location of a special feature, that could be found by a player?
If I did, I have forgotten what it was. Sorry I did once make the galaxy produce Mr. Braben’s face in stars as a test for being able to inject very bright O class stars, but that was removed pre-pre-pre Alpha.
10) How close is this identifier system to any existing official naming or identifier protocols currently used by scientists? Like, could we input future data we collect in real life into Elite?
Each generated body needs a unique identifier, but also any “authored” body, say from the stellar catalogues. Authored bodies, however, have their information pre-calculated, so only do partial proc-gen at most. The system is sensitive to adding new authored bodies to the system, as it could displace the identifier of other proc-gen bodies, changing the galaxy. It is possible to make changes, but we must be careful about it.
11) Why aren’t there dark regions on the other side of the galaxy?
Do you mean lower density regions between the spiral arms? If you could please forward on an X,Y,Z sector location (as seen from the Galaxy Map grid lines) I could have a closer look and confirm. Depending on where exactly you are on that side, there are still under-dense regions, but there may also be some bleed through from the galactic bulge data placing more matter in that region that immediately appears from the image in the Galaxy Map.
12) Will Nebulas one day resemble the Hubble painted shot?
One of the common discussions on the dev floor is about the level of visual exaggeration we portray to the players. For example, most nebula images you can see are false colour ones of non-visible EM wavelengths. Do we make radiowaves visible in-game to reflect these beautiful photographs? Do we go the realistic route of showing these hydrogen clouds as greyish, slightly greenish diffuse blobs? No promises, no guarantees, nothing to announce at this time, but I am always interested in potential improvements to the rendering of stellar bodies and phenomena.
13) Does the planet surface rendering use adaptive subdivision when making the hills and craters of the planets?
Currently, the subdivisions are in smaller patches with the same amount of points in the same square arrangement. This is used, rather than non-uniform dynamic tessellation, because in our system it allows a much faster and economical generation of both render and physics meshes. We blend between detail levels of patches though, to smoothly transition from low to high vertex density.
14) Have you thought about creating permanent, full textures for popular planets that get loaded frequently?
Such large texture collections would take up a lot of graphics memory. I understand and sympathize with some of the popping that users have been experiencing, but using up that available memory would mean that other textures in the game would pop quite a bit worse.
15) How come some stars are older than the Universe in Elite Dangerous?
The oldest stars in the real Milky Way can tend towards 13,800,000,000 years. The sectors themselves have a maximum average age of 12,810,000,000 years. Unfortunately, though, there is a small, rare, bug in resolving the range of ages across a few sectors, and there have been a few cases of the stated age if a star being around 18 billion years. Yup, that’s an oopsie. Bluntly fixing this will upset some generation and alter the galaxy, so a careful approach is needed for fixing this one up. It’s my list of work to address, apologies for the delay.
16) Does ED generate hidden geometry?
The word “patch” in this answer refers to a square of terrain. For planets? The base patches on the faces of those cubes that become the planets are always there, as the data might be needed at any moment if one is traveling fast enough. The finer detailed patches are only generated when it’s reasonable for the game to expect you to need that information, depending on your altitude and speed. There might be patch information which would be beyond the horizon and so not needed for rendering in this frame. In this case, the patch is culled from the list of things to render, reducing the work on the GPU.
17) Why are there regions of stars near the core where there are defined lines of difference… i.e. one side dense star fieldother side hardly any stars at all?
A good question; I do see the reddit posts about this one fairly frequently. There are some sectors which have a large density gradient between them. One sector is over a threshold for generating stars of the size that its layer looks after. The neighboring sector may be just underneath this threshold. As this neighbor doesn’t create any systems, it donates its mass to all its child sectors and so creates many bodies. The first sector has made some heavier stars, so donates a lesser amount of leftover mass. The result is that there is an overpopulated sector and an underpopulated sector. Not all cases of this happening were smoothed out before the initial release of Elite: Dangerous, and making any alterations now would upset the proc-gen of the entire Galaxy.
We are aware of it and are still mulling over which direction to take this in.
18) Do you have anything to say on the real life discovery of Trappist-1, with it being so close to the system which the Forge created?
“Well done StellarForge!”? Also, “Well done astrophysics and astronomy researchers! You rock!”
19) I’d love to know how you integrate the catalogued star systems (stuff we see from earth)!
We created a compiler that analyzed the contents of the Hipparcos and Gleise stellar catalogs of the time and created stellar forge system entries from the details. Some entries had the full details of the star, others only the brightness, colour and direction of the star, and others somewhere in between. This compiler would take the available data and fill in the gaps using the same calculations that would be used for proc-gen systems. It would also assign BodyAddress identifiers based on the sector they would be found in. When creating a sector in StellarForge, these “authored” systems are loaded in first, their pre-compiled data taking place of generated results. The authored system also take away the mass designated to the sector, like a generated system would.
The proc-gen systems are created later with the leftover mass. The game then treats the authored and the proc-gen systems identically. As for the contents of the star systems, we have other game data resources which Mike Brookes organised which link to a system for full or partially pre-made system layouts.
20) Will we be getting those high mountains and deep ravines back at some point?
The crazy ravines and mountains (mostly on “Rocky Ice” planets) were quite striking, yes. Unfortunately, they were also causing issues in the creation and handling of the physics mesh that you would drive on (or fly into if distracted). The errors that would be encountered were severe enough to cause a crash (this was seen in public as us pre-emptively kicking you to the main menu on approach to the planet). Removing the crazy examples of ravines/ridges was necessary to:
- allow the creation of physics patches
- not be entirely scientifically inaccurate
- avoid terrain which was sharp enough to look really unpleasantly jagged on VR setting.
There also used to be a few cases of a bug in the noise graph allowing the occasional mountain taller than a planet sustain, taking into account material properties and gravitation. These were just reduced to the maximally supported mountain height for the planet. We want to keep working on the planets and deliver improvements. Official people will say official things when the official time is upon us. For now, the short term work involves revisiting the planet colouration, as per the keynote from FX2017
21) How close was the old Elite 2/3 system generation compared to Stellar Forge? Are there any notable changes compared to David Braben’s original take on it or was he pretty close?
Mr. Braben worked very closely with the team to help ensure the approach was consistent but building upon his systems and that StellarForge covered any additions that were wished for at the time of Frontier and First Encounters. The maths behind the coarse level details of the models of stellar and planetary formation have not changed drastically since the 1990s, and so many calculations would be similar. What has changed is the understanding of things like how common binary pairs are and other statistical particulars.
22) Where does the initial mass component to a galactic sector come from? Real life observation, procedural generation or guess work?
Real life observations give us the approximate mass of the entire galaxy. There are various papers out there, some looking at the orbital velocities of globular clusters in the galactic halo, some trying to count types of stars in a region and extrapolate that across whole arms, some measuring the speed of stars at different orbital radii away from the core. The value we used was taken as an average from available research papers at the time. Observations of our and other spiral galaxies gives us a good idea of the distributions of that mass in 3d space.
23) How does star system naming work?
The unique identifier is transformed into a name. The sector address is encoded into a proc-gen “stellar catalog” name. The sector layer can be encoded in a single letter. Some of the numbers refer to the system within the sector at that layer.