Surface area has a substantial impact on osmoregulation. The more surface area exists in your body, the more of your body is exposed to outside elements for better and for worse. Volume is large but not the only contributing factor to surface area.
Surface area can be mitigated by less volume, or using coverings (cell walls, or other entire cells) that help reduce overall exposure. It can be increased by having thinner coverings, or folds that increase overall surface area without greater volume.
In the end, volume kind of introduces it’s own penalties to an organism (More nutrients required to reach such size, energy upkeep, resource transference, mass, pushing against gravity, etc) but it also contributes to surface area. Volume is just a single (albeit major) variable in the equation of surface area.
Optional ravings of a mad man
If you live in an environment with very high salinity, it is likely beneficial to have low surface area because it allows you to expend far less energy in pushing salt out of your body. Why? Because there’s far less area for salt to enter in. Think of it as kind of a war front. When you are in active conflict you don’t want your forces spread out across all borders, it will strain your military until it breaks. The less area of concern, the better.
On the other hand, having more surface area can be beneficial for the same reason. Your nose has sensory cilia designed to increase the total surface area of your chemoreceptors which helps pick up smells all the easier. Many plants have large surface area because it let’s them catch the sunlight better.
Oh yeah speaking of plants, that’s a significant reason behind why evergreen trees have nettles compared to deciduous trees. The significantly lowered surface areas of the leaves allows pine trees to handle the cold much better as there is far less surface area exposed to the elements. Elephants also have folded skin for similar reasons, allowing them to more effectively dissipate heat through the mud that collects on their skin. Having more surface area in your stomach allows you to more effectively digest harder meals, such as raw foods. But of course it also takes more energy upkeep. Humans have far less folds in their stomachs than many natural predators which is why raw food doesn’t do us much good. (Note that enzymes play a pretty large role in this too) Don’t get me started on herbivore stomachs, whew! And of course there’s the brain, with more surface area increasing the overall effectiveness of the brain’s functions without outright increasing size. I don’t really know the specifics of that but it’s important there or so I am told.
I’m getting a bit sidetracked here, but the point I’m making is surface area is HUGE like, really REALLY HUGE. The decision to go with more or less surface area is a very important decision to make almost everywhere in an organism. It all comes down to how much or little you want your assets to be exposed, and either choice has it’s ups and downs.
Now onto the subject of volume; It’s often rather synonymous with surface area as being bigger just adds more surface area as a consequence no matter what. That’s just the nature of being big. It’s volume that we mostly use to factor surface area in Thrive at this time just because it’s easy.
Anyway yeah sorry the spontaneous rant
Currently in Thrive we’ve implemented this as osmoregulation. Osmoregulation increases as you get bigger because you have more surface area. It’s reduced by cell walls because these walls help reduce (but don’t entirely prevent) exposure. In the future, this will become more impactful once environmental conditions are implemented. Being smaller will mean you are less affected by salinity, temperature, etc because there is less of you to be exposed to it. Of course, you can then have enzymes/proteins/contractile vacuoles to fight the good fight and give you more room to expand your surface area despite the conditions.
- sounds fine to me, it kind of already exists in a way with larger cells being able to just hoover up more compounds by virtue of having a bigger hitbox. Not really sure if we should expand it more than that, as it might not really be noticeable.
I agree with 2., though I would prefer we implement environmental conditions and their effects on the cell before we try adding the additional layer of transportation tax. Though maybe it would be better to implement the simpler method first…
Environmental conditions can help prevent a player from getting too big as larger size increases your exposure to the elements. More extreme conditions will have a sharper incline in osmoregulation. I see it as something like HexCount * (1+0.X) where X is the value of environmental condition outside of your range. EX: A 10 hex cell tolerant up to 45C existing in a 55C environment would have 10 * (1+0.10), or 11 osmoregulation cost. Probably not as sharp of an incline as we would want but it’s roughly what I’m looking for.