Things that are not in-scope:
- Fully-simulated Elite: Dangerous-style space flight (though this would be extremely cool)
- Super realistic star system generation (i would do this, but it is too hard!)
Things that are in-scope:
- Procedurally generated universe
- Fancy skybox that uses actually nearby star systems and planets
- Landable planets (Starbound-style: no seamless transition)
- Space stations/starships
-
Major constituents of spiral galaxy shape:
- galactic core/bulge
- disc
- thin disc, ~400 ly tall
- thick disc, ~1000 ly tall
- discs have exponential falloff
- halo
- spherical i think
-
lots of dust in central plane
-
high-level inputs
- mass of galaxy
- luminosity map
- defines shape (we can use a prcedural density function)
- luminosity:mass density map/region map
- defines which galactic region a given pixel is in (core/halo/arms)
- non-luminous dust contribution
-
octree
- 8 layers deep, 1280ly^3 -> 10ly^3
- each layer manages a mass range
- ie, higher-up layers generate more massive stars, deeper layers generate less massive ones.
- generation range around the cursor is smaller near the core because there just so many stars there
- nodes inherit leftover data from parent
- mass, age, metallicity, type
- metallicity -> ratio of dust to gas, "typically done with iron"
- generates sytems until it has run out of mass or IDs
-
sector generation
- create a single primary star
- star creation driven by system age and mass
- different star lifecycle stages have different mass/whatever relationships
- derived properties
- radius
- temperature
- classification
- color
- luminosity
- add planetary nebula if needed
-
system generation
- create main stars
- create protoplanetary disc from leftover mass from star formation
- generate clumping in stable zones
- progress simulation through time!
- find stable orbits and populate them
- roche limit (inner stable orbit), hill sphere (outer stable orbit)
- max stable orbit is about ~1/2 the radius of the hill sphere