C-System Bodies

Basics

Colony Cost

The colony cost algorithm has been updated for C# Aurora to include hydrosphere extent, low gravity and tide-locked worlds and to change the rules for dangerous gases and max pressure. The new calculation is as follows:

Gas Giants, Super Jovians and worlds with a gravity higher than species tolerance cannot be colonised and therefore have no colony cost. Every other body has a colony cost that is equal to the highest colony cost factor from the following list:

Temperature: If the temperature is outside of the species tolerance, the colony cost factor for temperature is equal to the number of degrees above or below the species tolerance divided by half the total species range. For example, if the species range is from 0C to 30C and the temperature is 75C, the colony cost factor would be 45 / 15 = 3.00. The colony cost factor for tide-locked planets is 20% of normal, so in the example given the colony cost factor would be reduced to 0.60.

Atmospheric Pressure: If the atmospheric pressure is above species tolerance, the colony cost factor for pressure is equal to pressure / species max pressure; with a minimum of 2.00. For example, if a species has a pressure tolerance of 4 atm and the pressure is 10 atm, the colony cost factor would be 2.50. If the pressure was 6 atm, the colony cost factor would be 2.00, as that is the minimum.

Breathable Gas: If the atmosphere does not have a sufficient amount of breathable gas, the colony cost factor for breathable gas is 2.00. If the gas is available in sufficient quantities but exceeds 30% of atmospheric pressure, the colony cost factor is also 2.00.

Dangerous Gas: If a dangerous gas is present in the atmosphere and the concentration is above the danger level, the colony cost factor for dangerous gases will either be 2.00 or 3.00, depending on the gas. Different gases require different concentrations before becoming 'dangerous'. Halogens such as Chlorine, Bromine or Flourine are the most dangerous at 1 ppm, followed by Nitrogen Dioxide and Sulphur Dioxide at 5 ppm. Hydrogen Sulphide is 20 ppm, Carbon Monoxide and Ammonia are 50 ppm, Hydrogen, Methane (if an oxygen breather) and Oxygen (if a Methane breather) are at 500 ppm and Carbon Dioxide is at 5000 ppm (0.5% of atmosphere). Note that Carbon Dioxide was not classed as a dangerous gas in VB6 Aurora. These gases are not lethal at those concentrations but are dangerous enough that infrastructure would be required to avoid sustained exposure.

Hydrosphere Extent: If less than twenty percent of a body is covered with water (less than 20% Hydro Extent), the colony cost factor for hydro extent is (20 - Hydro Extent) / 10, which is a range from zero to 2.00.

Low Gravity: If the gravity of the body is lower than the species tolerance, the colony cost factor for gravity is 1.00. In addition, the overall colony cost for the body will be suffixed by 'LG', for example 2.00 LG, which indicates that low gravity infrastructure is required for any population on that body. Normal infrastructure will not count toward the supported population. Date 03.03.2018

Population Capacity

A new concept, Population Capacity, has been added to C# Aurora. This represents the maximum population that can be maintained on a single body and is primarily determined by surface area. This is the total of all populations on the same body, not per population.

The Earth's population is currently seven billion. However, the rate of population growth peaked at 2.1% at four billion, has been dropping since then (now 1.2%) and is projected to reach close to zero around eleven billion

https://ourworldindata.org/world-population-growth/

Therefore, I am going to use twelve billion as the baseline max capacity for an Earth-sized planet and four billion as the point at which growth rates are affected. Growth will follow the normal rules for up to 1/3rd of max capacity and then will fall off at a linear rate, hitting zero growth at max capacity (replicating the situation on Earth). The max capacity of a body will be equal to: (Surface Area / Earth Surface Area) * twelve billion. I will add some tech options to improve that capacity, particularly for smaller bodies. A planet can physically hold more people than the max capacity but this will result in unrest due to overcrowding.

While 70% of the Earth's surface is water, that plentiful water also improves living conditions (the majority of the world's population is less than 100 km from the nearest coastline). However, there does come a point when too much water will reduce the available living space. Therefore, once water covers more than 75% of the planet, capacity will drop at a linear rate, falling to 1% of normal capacity at 100% water. The 1% assumes a few, small, scattered islands or some form of colony floating on the surface.

Tide-locked worlds (one side always facing the star) have only 20% of normal capacity (after taking into account surface area and water). This is to simulate that the population will be living in a narrow band between the light and dark hemispheres of the planet. To compensate, these worlds also have an 80% reduction in the colony cost factor for temperature (as they are living in the temperate band).

Regardless of the result of the above calculations, a body with gravity at or below the species maximum that is not a gas giant or super-Jovian will always have a capacity of at least 50,000.

The above rules result in the following population capacities

http://www.pentarch.org/steve/Screenshots/PopCapacity.PNG

EDIT Jan 21st 2017: Each Species has a population density modifier. This is normally set to 1 but there a small chance it can be higher or lower for random species. Player-created species can specify this density. Date 21.01.2017

Terraforming

In terms of the general mechanics, terraforming works as it does in VB6 Aurora. Atmosphere measured in atm (atmospheric pressure) is added by terraforming ships or installations. However, there are several significant changes for C# Aurora.

1) The base terraforming technologies have their atm rates reduced by 75% at the lower tech levels. The rate of tech increase has improved so the higher tech levels are reduced by around 60%. The starting racial tech rate per module/installation is 0.00025 atm per year.

2) Smaller planets are much faster to terraform. The terraforming rate in atm is modified by Earth Surface Area / Planet Surface Area. For example, the rate at which atm is added to Mars is 3.5x faster than on Earth (1.4x faster than in VB6 Aurora), Ganymede is 6x faster and Luna is almost 14x faster (5.4x than VB6)

3) System Bodies with gravity of less than 0.1G cannot retain atmosphere and therefore cannot be terraformed

4) Carbon Dioxide is now a dangerous gas.

5) Water is now a significant factor in terraforming planets. Any planet with less than 20% water has a colony cost factor for water equal to (20 - Hydro Extent) / 10 (see colony cost rules at C-System Bodys).

6) Water vapour can be added to the atmosphere just like any other gas.

7) Water vapour will condense out of the atmosphere at a rate of 0.1 atm per year and increase the planet's Hydro Extent

8) Each 1% of Hydro Extent requires 0.025 atm of water vapour. This means that creating 20% Hydro Extent would require 0.5 atm of water vapour (this will be much faster on smaller worlds because the speed at which water vapour atm is added is linked to surface area). With this in mind, existing water becomes an important factor in the speed at which terraforming can be accomplished, especially on larger worlds.

9) Water will also evaporate into the atmosphere. The evaporation cycle follows condensation and will stabilise water vapour in the atmosphere of a planet with liquid water at a level of: Atmospheric Pressure * (Hydro Extent / 100) * 0.01 atm. The resulting atm * 20 is the % of the planet's surface that loses water. As the water vapour is removed from the atmosphere, it will replenish from the surface water. This is to allow the removal of water from ocean worlds to create more living space.

These new rules should add more variety to terraforming and, in conjunction with the max population rules, should add more interesting decision-making when choosing which worlds to terraform. Date 02.03.2019

Terraforming will change the terrain (Planetary Terrain) under two circumstances:

1) A planet with a base type (Barren, Mountain and Rift Valley) becomes eligible for another terrain of a similar type. Mountain can move to any other Mountain type, Rift Valley to any other Rift Valley Type and Barren to any non-Mountain, non-Rift Valley type.
2) The terrain type is no longer possible with the current environmental conditions. A new terrain type is generated with the same base type.

Date 16.09.2018

Mineral Generation and Geological Survey

Mineral Generation at system body creation

Normal mineral generation (at system body creation) has three phases:

1) An overall roll for the potential for minerals to be present, based on radius, density and system abundance. If this roll fails, the body has no minerals.
2) A roll for each type of mineral to be present, based on density and abundance. Duranium has twice the chance of any other mineral.
3) A roll for the accessibility of each mineral generated in step 2). This is based on radius.

Date 07.04.2018

Geological Survey

Once the orbital survey of a system body is completed, the potential for a further ground survey will be revealed (None, Minimal, Low, Good, High, Excellent). The ground survey requires the same survey points as the orbital survey, except they are generated by ground forces. Only system bodies with a diameter of at least 4000 km will be eligible for a ground-based survey (in Sol that is Mercury, Venus, Earth, Mars, Ganymede, Callisto and Titan).

Once the ground survey is completed (assuming potential is Minimal or higher), a new mineral generation roll will take place. For this roll:

Step 1 is the same regardless of the potential.
Step 2 is modified by the potential. Minimal is 25% normal, Low is 33% normal (same as teams in VB6), Good is 50% normal, High is 100% normal and Excellent is 200% normal.
Step 3 is modified by High (+ 0.1) and Excellent (+ 0.2). All others are same as normal.

If a deposit of a mineral that didn't previously exist is generated by the ground survey, that deposit is added to the system body.

If a mineral deposit is generated by the ground survey and a deposit of that mineral already exists on the system body, the existing deposit is changed to match the amount or accessibility (or both) of the ground survey deposit if the latter is greater.

The chances that an eligible body (4000 km diameter) will have ground survey potential is equal to: None 60%, Minimal 20%, Low 10%, Good 6%, High 3%, Excellent 1%.

Date 27.01.2019

System Bodys

Comets

Colony Cost of Comets

In VB6 Aurora, the colony cost of comets was not a major concern as there was no low gravity infrastructure. For C#, comets could potentially contain populations, albeit small ones.

Therefore temperature and colony cost now update as comets move towards and away from the sun. This means the population supported by infrastructure will change as well over time. The distance displayed on the system view is the current, rather than maximum, distance.

You can flip between current and max colony cost on the System View and it is displayed on Colony Summary of the Economics window and on the Body Info tab of the Tactical Map.

The Unload Colonists Standing Order will ignore comets, so civilian traffic will not attempt to place colonists on comets about to disappear into the void.

I may add some larger comets to make this more interesting. Longer-term, I may also add eccentric planetary orbits with a similar approach to the above. This is an experiment on a small scale to see what issues I encounter

http://www.pentarch.org/steve/Screenshots/Comets002.PNG

Date 09.11.2018

Gas Giants

Gas Giants, Super Jovians and worlds with a gravity higher than species tolerance cannot be colonised and therefore have no colony cost. Date 03.03.2018

High Gravity Bodys

Gas Giants, Super Jovians and worlds with a gravity higher than species tolerance cannot be colonised and therefore have no colony cost. Date 03.03.2018

Low Gravity Bodys

Any low gravity bodies (below the minimum gravity of the colonising species) will now have a normal colony cost calculation (based on atmosphere, temperature, pressure, etc.) and an 'LG' suffix will be added. For any bodies with an LG suffix, the maximum supported population will be based on the available LG-Infrastructure.

For example, for a colony cost 2.00 world you need 200 infrastructure per 1m pop. For a colony cost 2.00(LG) world, you will need 200 LG-Infrastructure per 1m pop and normal infrastructure will have no effect.

Both normal infrastructure and LG-Infrastructure can be used on a world with gravity in the tolerable range. Worlds with gravity above max species gravity will not be colonizable.

Civilian infrastructure production on a low gravity world will be LG Infrastructure, produced at one third of the normal rate (same overall cost). Trade in infrastructure will be low gravity to low gravity or acceptable gravity to acceptable gravity. Date 06.12.2018

If the gravity of the body is lower than the species tolerance, the colony cost factor for gravity is 1.00. In addition, the overall colony cost for the body will be suffixed by 'LG', for example 2.00 LG, which indicates that low gravity infrastructure is required for any population on that body. Normal infrastructure will not count toward the supported population. Date 03.03.2018

System Bodies with gravity of less than 0.1G cannot retain atmosphere and therefore cannot be terraformed Date 07.12.2018

Tide-locked Worlds

Tide-locked worlds (one side always facing the star) have only 20% of normal capacity (after taking into account surface area and water). This is to simulate that the population will be living in a narrow band between the light and dark hemispheres of the planet. To compensate, these worlds also have an 80% reduction in the colony cost factor for temperature (as they are living in the temperate band). Date 21.01.2017

Planetary Terrain

As part of the ground combat changes, each planet will have a dominant terrain type. In many cases, for most asteroids, comets or small moons, that type will simply be Barren. Within certain environmental tolerances, other terrain types are possible.

Any system body with temperature lower than -100C or higher than 200C or with no atmosphere or atmosphere greater than 10 atm will be Barren, unless it has platelet or extreme tectonics, in which case it will be Mountain.

All other system bodies will check the following table to determine which terrain types are eligible based on the environmental conditions. One of the eligible terrain types will be selected randomly. Barren, Mountain and Rift Valley (which are base types available without any atmospheric, temperature or water requirements) will only be selected if no other terrain types are eligible. The tectonic numbers are internal to Aurora and have the following values: Dead = 1, Hot Spot = 2, Plastic = 3, Plate Tectonics = 4, Platelet Tectonic = 5, Extreme = 6.

Terraforming will change the terrain under two circumstances:

1) A planet with a base type (Barren, Mountain and Rift Valley) becomes eligible for another terrain of a similar type. Mountain can move to any other Mountain type, Rift Valley to any other Rift Valley Type and Barren to any non-Mountain, non-Rift Valley type.
2) The terrain type is no longer possible with the current environmental conditions. A new terrain type is generated with the same base type.

I am happy to add additional types or modify the environmental parameters if there is general consensus on any changes.

The fortification modifier is a modifier for the max fortification level, rather than an automatic defence increase. It means you can dig in much deeper (given sufficient time) in Mountains than you can in Steppe or Swamp. The to hit modifier is a reduction in the chance to hit in that terrain (for other ground units and any supporting ships in orbit). In effect, fortification is a benefit to the defender, while to hit is a penalty to both sides. Within the new ground combat rules, you can assign ground units 'capabilities', such as Jungle Warfare, Mountain Warfare, etc. which will double their chance to hit in those types of terrain. Ground units of species with certain types of home world may gain capabilities for free (if you are from a desert planet, you would gain Desert Warfare for free, for example). There are additional capability options to avoid penalties for ground units fighting on worlds that are outside their species tolerance for gravity, temperature and pressure.

An important factor to bear in mind is that when ships are engaging ground units with surface-to-orbit capability, the main defence of the ground unit will be its fortification level. The ship-based weapons are assumed to hit 100% of the time divided by the fortification level. On a planet with Steppe as the dominant terrain type, the maximum fortification of a static ground unit will be 6 with no penalty for the ship to hit. On a Jungle Mountain world, the maximum fortification level will be 18 for that same ground unit and any shots against it by the ships will be modified by 0.125, giving the ground unit an effective fortification level of 144. In other words, the ship in orbit is going to hit once every 144 shots. So trying to use orbital bombardment against surface to orbit units buried in jungle-covered mountains is going to be a Bad Idea. It would be far more effective to send in ground forces (which can't be hit by STO units) to dig them out. That is an extreme example, but there should be many more situations where there are some serious decisions for the attacker.

http://www.pentarch.org/steve/Screenshots/DominantTerrain.PNG