Few months have passed and the new engulfment mechanic is shaping up nicely. Here’s a summary of the overall progress and what ended up being implemented for future reference as of the current state of this revamp’s pull request at the time of writing.
The engulfment process for any valid engulfable objects starts upon immediate contact with the engulfer’s membrane, this completely removes the ability for preys to escape engulfment so they have to find another way to combat this. Few things already proposed:
(overall engulfment process)
The initial step in engulfment is planned to be visualized with pseudopods, this is where part of the membrane stretch out onto the engulfable objects, enveloping them and finally pulling them in. There has been some progress on this front thanks to @Nunz, so it will likely be added in the near future. For now it will just look like the clip above. Also if you haven’t noticed already, there are “bubbles” forming around the engulfed things. This visualizes phagosomes (or endosomes? can’t tell the difference). I wanted to add more intracellular action by animating the fusion of lysosomes and phagosomes to more accurately replicate the real-life process but I think I’ll reserve this for another time.
If the ingested food can’t be digested it will be thrown out. And if the cell is already full of compounds, its digestion process pauses until it needs food again, allowing you to stock up food.
(Iron chunk immediately getting ejected as the cell can’t digest it)
Next comes the digestion, not with a fixed duration anymore, instead the duration scales with the volume of the compounds contained within the food and is also affected by lysosomes which I’ll explain shortly. Toxin damage from toxic cells is now implemented and works the way how I described on the previous post. Damage scales with quantity so don’t try to eat lots of toxic things at once as your cell would explode (exaggerating). Note that currently lysosomes doesn’t neutralize toxic cells as I’m not sure if it’s really what they do (instead I think it’s peroxisomes?), would love to hear a scientific basis on this.
Lysosome which is now implemented is what you will use to make digestion 20% more efficient and faster for each placement, only available for eukaryotes, prokaryotes however only get 40% (values subject to change) of compounds yielded from engulfment. This incentivizes the players more to get a nucleus to evolve predator based microbes. For more details about lysosomes refer to the links and posts above.
The cell’s metabolism also plays a major role. Engulfment and digestion can be an unreliable method to acquire energy if the cell is highly active; higher energy output + slow inefficient digestion = energy deficit. This amplifies the need for lysosomes. A balanced metabolism and digestion can make for a fearsome apex organism.
(New Lysosome organelles)
I think that is all for now. There are still much more to do, so this revamp is in by no means complete yet. All in all I think this goes to show how in-depth a single gameplay mechanic for Thrive can be and just how much we can make it further engaging and interesting for players even for an existing one that has been around probably as old as the game itself by just giving it a bit of a touch up.