Telos wrote: ↑Fri Dec 28, 2018 2:46 am
Intuitively though, there are lots of asymmetries between these different planet types. For example, it'd be relatively easy for a nuclear-capable species to turn any livable planet into a toxic or irradiated hellscape, whereas turning a toxic or irradiated hellscape into a livable terran-like world is far beyond our current technological capacities.
It could be interesting to set up a terraforming system that intuitively reflected some of these asymmetries.
Here you are wading across the water of realism. Realism is seldom considered in this game, unless it brings in a better gameplay experience or it does not create any burden and it is undisputable (which is probably impossible). I will put some examples of dispute about your expectations regarding planet terraforming:
A toxic planet (e.g. venus) could be covered by satellites that reflect out all sun's light until temperature goes down enough, water can be brought again with ice asteroids or even making it from oxygen and hydrogen; in a radiated planet (that usually is such because it has no magnetic field to fence off the sun's radiations), something could be done with the planet's nucleus or its atmosphere reduce radiation on the surface.
Roughly 4 of the planet types (Terran, Ocean, Swamp, Desert) seem to be involve familiar life, and maintaining balances in temperature, atmosphere, and water-cycle that are fairly friendly to familiar life. These all seem to be delicate complex systems that it would take a great deal of effort and planning to orchestrate.
Realism-wise, an ocean planet is nothing similar to a terran planet. In an ocean planet there is no dry surfaces, so there is no rain falling on the ground and taking stuff into the water, so several chemical processes that naturally occurs in Earth's surface would not happen in an ocean world. Earth's fishes and algae wouldn't survive in there.
Also, tundra planet (ice planet) should be included in this list (unless we are talking about temperatures too close to 0 K).
Roughly 3 of the planet types (Toxic, Radiated, Barren) seem primarily just to characterize the atmosphere of the planet, without specifying much about temperature, water content, ecosystems, etc... These all intuitively seem to be states that could be brought about quickly by crude weaponry, without much planning or careful orchestration.
More could be assumed about this environments characteristics: barren planets are supposed to have no atmosphere, low temperatures (or at least not high enough to be an inferno planet) and be covered by regolith (no organic resources). Composition could be any combination of ices, rocks and metal. Toxic can be assumed to be venus-like planets where the atmosphere is dense, hot and acid, with no liquid water (only remnants in high layers of atmosphere). Radiated should be something very similar to barren, unless we assume barren planets have an active magnetic field (why not).
The remaining 2 terrain types (Tundra and Inferno) seem primarily just to characterize the extreme temperature of a planet, without specifying anything about atmosphere, water, etc... Altering these generally would require immense changes in energy flow on a planet.Many frozen planets are so far from stars that there would be no feasible way of thawing the whole thing. Many infernos are so close to stars, and/or so strongly churned by gravitational tidal forces from nearby masses, that there would be no feasible way of cooling them. If you could cool an inferno, e.g., by adding enough reflective gases to its atmosphere to prevent intake of solar energy, there's no obvious reason to think the result would be one of the game's "neighboring" types (toxic or radiated) rather than any of the 5 other non-frigid types.
Appart from modifications of the atmosphere to boost greenhouse effect or albedo, in both cases, changing the orbit could help. Since we can move planets between solar systems in FreeOrion, we can change orbits within a system.
if you could add enough greenhouse gases to thaw a tundra, that seems just as likely to produce a terran or ocean world as a barren world.
The main and only reason if simplicity.
The thing is current system of environments is anything but realistic, and developing a realistic environment system that also takes into account planet composition (not the same a rocky-icy barren than a rocky-metal one than a icy-metal one...; not the same a gas giant than an ice giant, etc.) could be interesting but I doubt that many players would like it. I myself have been fiddling with all this stuff, because I'm a realism-aholic, but the level of complexity it could and should reach to be "really" realistic is too much for most people.
Regarding the actual suggestions you make at the end, I see they are still deeply unrealistic, brings in no better gameplay (no new strategies, just different ways to do the same strategies, with same or worse micromanagement requirements) and brings in some extra complexity.
However, I do love asymmetries and I'd love to see something that makes some environments better (in general, for most species) than others, so that there would be an asymmetric colonisation pressure. Would be nice to hear what developers thing about that single point.