Macroscopic Editor, Progression, and Principles

Deus · November 8, 2022, 6:12pm

I think that’s more a question specifically related to progression more so than the underlying mechanics of the macroscopic editor. After trying to make an editor concept while trying to keep progression (specifically, early eumetazoan evolution) in mind, I can say it’s pretty difficult to create a universally applicable editor by limiting focus to a specific era of evolutionary history while trying to extrapolate these findings to other eras of evolutionary history at the same time. Like Buckly has done, I think it’s better if we create general principles and envision general mechanics first, then think of specific case studies and refine the details as we go along, which is something I’ll be focusing on.

Also something of interest: Williston’s Law. A user on the community forums in this thread (Questions about the realistic implementation of repeating parts/segments (and Williston's law) - Multicellular Stage - Thrive Community Forum) put it this way:

“most organisms have ended up with their characteristic arrangement of parts by first evolving many similar parts and then specializing or losing those parts over time.”

Hence, for example, many types of bony fish having more fins than tetrapods have limbs, or the ancestor of arthropods tending to have many more limbs than current arthropods such as was seen in trilobites. Note that Williston’s Law isn’t necessarily canon - currently scientists prefer explanations of variances in evolutionary rates more than general principles of morphological complexity - but it could be a line of thinking which is implemented well in Thrive given the more artificial nature of our evolution. It also reveals that early on in metazoan evolution, experimentation with limbs was rather frequent; it was complexity which transitioned the focus more to tweaking existing structures rather than creating entirely new ones.

I think ultimately that we’d want to have a split between how we treat the creation of limbs (initial investment) and the modification of limbs. We’ll probably want the initial investment to create a limb be more expensive than the modification of limbs in terms of MP. We’ll also probably want to vary the cost of both of these depending on the player’s morphology; so for example, a vertebrate analogue will have to spend a lot more MP than an arthropod analogue to create or modify their limbs. We’ll also probably want to balance/calibrate states related to things such as movement speed or something so that as a player’s limbs get more complex (perhaps in joint count?), they’ll be encouraged to have different limb structures. So for example, vertebrate limbs would be most efficient in terms of speed with either two or four limbs on the ground, with 3 joints in each limb. Arthropod limbs will have slightly more leeway (ants have 6 limbs with 3 joints in each limb, whereas tarantulas can have 7 joints in 8 legs), with more joints and limbs reducing speed but increasing agility for example. These two factors combined should allow us to encourage players to prefer spending MP on the editing of limbs after a while.

But in regards to more specific features that showed up later in evolutionary history, such as the evolution of fur and the such, you have a valid point. We should probably think of a sort of unlocking method in that regard.

PS: I would also like to note that’s vertebrates fundamentally have inherited a development pattern from their ancestors that makes it genetically harder to coordinate the development of additional limbs too. So we do have some grounds of, after a certain point, abstractly bumping the costs of creating limbs for organisms with an endoskeleton.

Buckly · November 19, 2022, 3:24pm

A bit late to the party, I know, but if it really comes down to it we could potentially end up hiding parts the player cannot utilize in later stages of the… stage.

Obviously we will need a way for the player, and autoevo, to create new limbs at some point, not to mention freebuild which should remain pretty unfettered. So I believe the overall features of the editor are fine, we just need to consider how it changes while the player progresses.

One idea of my own I’ve been toying with, is the idea of committing players to a sort of progression path tied to their choices. These would lock them out of certain parts, but unlock others. The first of which would arise in the transition between microbe and multicellular. Whichever membrane-type their cell possessed would become the defining type. They would no longer be able to alter their membrane type, but may gain access to new associated features. For instance, cellulose organisms would have access to bark and trichome coverings later on, but would not have fur or scales.

The development of advanced bodily support too could be a part of this. endo/exoskeletons would prevent the player from creating brand new limbs, forcing them to creatively alter the limbs they already have. It would basically be the crossroads between …whatever and a proper animal. Not sure what we could give in return though…

I’m sure we can all agree that it would suck if after progressing you just suddenly lose access to parts, it would be pretty jarring. But as organisms become more complex they can no longer throw new limbs and bones on themselves willy nilly, so we would need to make sure the player always has some form of tradeoff in return.

Whatever the case may be, it’s certainly a matter of progression that we need to consider. I think the editor concept I have outlined is fine for a general overview for the future.

MirrorMonkey2 · December 20, 2022, 9:45pm

I thought about Bucklys suggested macroscopic editor interface and overall I really like it. But I have one important gripe with the internals tab: In my opinion the left panel feels a bit empty and devoid of information when it only shows the tissue types. In my opinion it could be better utilized by integrating some information about the metaballs into it instead of displaying these metaballs data in a pop-up menu.
As I understand it, this proposed metaball context menu would pop up in front of the organism. imo this is suboptimal as I think it would be better if you see the metaball you’re editing while doing so.

I therefore propose that the left panel includes a category called “segments” (I think this may be a more intuitive term for metaballs to use in-game). This category contains all the metaballs which the player can name to keep track of their function/position. As you can see, in my example the player has named them Head, Upper Abdomen, Lower Abdomen and so on.

Each segment section, when opened in the left panel, would include a list of that panels organs, as well as the tissue types which are contained within that segment but aren’t part of an organ.
The left panel functions much like a set of spoilers within spoilers which can be opened and closed as needed, much like many of our menus function. But there is an alternative way to quickly jump from segment menu to segment menu: Clicking on a segment of the organism will bring you straight to that segments menu and close all other segment menus.

Clicking on “Add Tissue Type” would send you to the top of the left panel where you can select a type to place in this segment from a library of all tissue types in the organism.
Clicking on one of the organs would open an organ pop-up window. This organ pop-up would open to the right, in front of the organism. This is consistent with the idea I layed out before: When you click on the metaball on the right side of the screen, the corresponding menu opens next to it, on the left side of the screen. When clicking on an organ on the left side of the screen, its corresponding menu opens next to it, on the right side of the screen.

I hope that I explained my suggestion as clearly as possible. I will sketch up a organ menu pop-up if needed. If I have time I may also do a simple animation of how clicking on a segment would open that segments menu and so on. Some of these things may be more easy to explain as a series of moving images rather than some rambling paragraphs.
(Btw @Heath I borrowed your critter for this concept muck-up, I hope that’s ok)

Buckly · December 21, 2022, 3:17am

You raise a good point! Being able to avoid a popup menu would be nice as it clears up the player’s vision.

Using the left panel to display the statistics of the currently selected metaball is a pretty great idea, though I fear that listing all of the individual organ sets and such may end up feeling overly cluttered and messy.

I am personally in support of replacing the left menu with the selected part’s details whenever the user selects a part, but otherwise it would just display available tissues.

That being said, I am by no means an experienced graphics designer, so I’ll let the graphics team have the final say in the matter.

MirrorMonkey2 · December 21, 2022, 10:06am

Thanks for your reply! I think I get what you’re saying and I’m going to make an alternative mock-up which takes these changes into account. I may not fully understand what you mean by “organ sets”, but I’ll just go with my interpretation of what that means:)

Deus · March 3, 2023, 10:23pm

I had this thought train about how we can deal with developing playstyles in the late-multicellular/Aware Stage. I think this stage will be Thrive’s cool “gig” in a way, considering there are no similar games representing player-controlled evolution in as scientific of a way as possible. It is also the stage of life where evolution will happen the most quickly and lead to the most diversity of playstyles, so it is important to get it down right.

There isn’t much of a concrete mechanic suggestion here; rather, it’s a suggestion on how we can think about things going forward.

PHYLOGENY AND DEVELOPMENT

We would be interested in representing the evolution of metazoans (animals) and plants in this part of the game. Given just how much diversity there is in the body-plans of macroscopic organisms, this is a vast undertaking. So we need to be deliberate and methodical in how we approach the implementation of various unique adaptations. If we’re too shallow with what we implement, then there will be very little replayability in Thrive and many shallow mechanics - if we’re too detailed in everything we implement, nothing will ever happen.

In my mind, the best way to address things is by looking at phylogenetic trees and focusing on a specific clade as we work through upgrades.

(skip this paragraph if you understand the diagram above) Just to review phylogenetic trees quickly in case anyone in the larger community reading this is rusty on them, they basically map out the evolutionary relationship between different groups of animals. The number of “splits” there are between different groups indicates how closely related they are. So in this diagram, you can see the line leading to Cnidaria (jellyfish & coral) and Ctenophora (comb jellies) indicates that Cnidaria and Ctenophora developed pretty early in the evolution of metazoans, splitting off from other metazoans very quickly. Here is a basic introduction to the topic: Phylogenetic Tree Basics - YouTube

As far as I’m aware, this particular image isn’t necessarily the “definitive” phylogenetic tree of metazoans - there are various phylogenetic trees online, with various levels of detail. The important thing though is that these diagrams present us with a clear understanding of how different animals relate to each other.

There are also phylogenetic trees for each group of metazoans. Here is a phylogenetic tree for Cnidarians…

So essentially, by looking at the larger eumetazoan phylogeny tree, we have the complete tree of life in our hands. So, what I think will work best is to focus on a specific part of the tree for a specific series of patches. We can determine what to focus on first based on how early in the evolutionary history of eumetazoans a specific group appears.

We obviously cannot represent every single species within a family, so our job will be determining what collection of cool adaptations will best represent the phylogeny of a specific clade, and then choosing a collection of cool traits from the various subphylum within said phylum to adequately represent a given species.

So for example, this can be how we breakdown the Cnidaria…

Cnidaria

Cnidarians include Medusozoa, the group which includes all the” traditional” jellyfish and Anthozoa, which includes coral and other sessile organisms. We will likely want to focus most on Cubozoa and Scyphozoa (Medusozoans) to represent the two forms of major forms of jellyfish. We will also want to focus on coral, though they are more adequately represented by sessile gameplay and should be considered there.

Hydrozoans are the most numerous group of Cnidarians, though many are characterized by their tiny size (might not need many dedicated parts) and colonial nature (something we probably won’t simulate). There are also other forms of Medusozoans, though they are largely sessile, so there might be overlap with coral.

Medusozoa (Primarily Cubozoa and Scyphozoa)

Medusozoa tend to be motile, are radially symmetrical, and have nematocysts which allow them to sting. Some use their appendages to poison prey, though others have minimal predatory capacity and instead prefer filter-feeding using those appendages.

How to Represent Medusozoa

Their “floating” nature can be represented by allowing players to alter their mesoglea/buoyancy, and their stingers and tentacles can be represented by allowing players to develop appendages. Many of these appendages are like the familiar tentacles, though some are larger, expanding surface area.

How to Represent Scyphozoa

Scyphozoans are known as the “true jellyfish”. There are roughly 3 orders of scyphozoans, and perhaps up to 400 species. They tend to be larger than hydrozoans and contain a slightly more complex movement pattern which allows them to move at their size. Variance within Schyphozoa can focus on the presence or ratio of tentacles and oral arms. Some groups have many tentacles and no arms, some have arms and tentacles, others have no tentacles and only arms. Behavior variances also exist.

Thus, we can probably adequately represent Scyphozoans within Thrive by allowing variation in the number of tentacles and oral arms. Size will also naturally play a factor.

How to Represent Cubozoa

Cubozoans are box jellies. They are characterized by their potent toxicity and their more box-like shape. Cubozoans are known for having a rather complex nervous system and more capable sensory than other jellyfish. They can also swim pretty fast for jellyfish.

Thus, box jellies can be adequately represented in Thrive by allowing customization of the effects of jellyfish stingers (nematocysts). They will likely naturally emerge as players with Cnidarian-esque body plans enhance their nervous system and sensory capabilities.

Other

Hydrozoans exhibit a good amount of diversity in the capability of their appendages. For example, some projectiles are merely grabbing/restraining rather than poisonous. That could be a relatively simple inclusion to diversify combat, akin to the toxin system in the Microbe Stage. They are also known to be rather small at times, though this can vary.

There are various types of sessile Medusozoans. These can be used to diversify sessile gameplay, though they aren’t necessary in my opinion.

Here we have a pretty simple way of representing an entire group of animals in Thrive with just these steps…

Allow mesoglea and customization of buoyancy/density.
Include appendages akin to oral arms and stinging nematocysts.
Allow customization over the number of these appendages, the effects of these appendages, etc.
Implement other global mechanics, like the evolution of sense and such.
(Bonus) Implement some sessile gameplay capacities with Cnidarians.

That’s much more manageable than going through every single living jellyfish and throwing out some ideas, no? We can implement these and go on our merry way to represent other organisms.

I understand that doing this for every clade can look daunting, but we definitely can simplify things. For example, did you know that “worms” are represented across a huge variety of clades? There are mollusc worms, annelid worms, nematode worms, platyhelminthes worms, etc. Many shared traits exist between many groups of organisms, so we can oftentimes knock out various clades at the same time. Or atleast, be able to repackage various adaptations/mechanics for future traits. Jellyfish appendages can translate to octopi appendages eventually. It also helps to realize that players will have a lot of fun in combining various traits from various clades; we don’t have to necessarily think of things as being so specialized.

Of course, there are certain clades that will require a lot of focus. Vertebrates, Crustaceans, Molluscs, and Hexapoda as examples. But if nothing else, I think this approach to developing the macroscopic stages will be the best way to approach this daunting task from a design perspective:

Research a clade. Familiarize yourself somewhat with the orders of said clade.
Find out the defining traits of the clade and its various orders. There are many of course, but simplify your list to the least amount of traits for the most amount of diversity. Identify some traits which might be bonus objectives as well.
Then, we start developing this group of animals, focusing on them for a series of updates.
Once all “bottom-line” traits are implemented, repeat the cycle with a new clade.

Buckly · March 8, 2023, 5:20pm

I think this is a great run-down of the process of accounting for potential variety in Thrive. Maybe I’ll post a link on our wiki page to this, or condense it into a paragraph to help prime new designers on finding inspiration for features.

That being said, we must be ever mindful of casting too wide a net when it comes to creature editing, lest players become rather overwhelmed.

Deus · December 15, 2023, 8:02pm

Hello all,

As I’ve been getting more motivation to get involved with Thrive again, I’ve been dumping some thought into this topic just to get the creative juices flowing. I wanted a rough idea of the macroscopic stages - more specifically, I wanted to create an outline of how we could go about representing the most number of organisms with the least number of features necessary. So to go about this endeavor, I read a bit into phylogeny and taxonomy, and tried to characterize various groups of organisms I noticed.

I have a clade-by-clade breakdown below, but first, I wanted to note some general thoughts I’ve had as I went about this exercise…

Mechanics Over Parts - Thrive’s early macroscopic stages will likely be carried more by underlying mechanics shared by most organisms and less by unique “parts/traits” giving abilities relative to the later portion of the macroscopic stage. Before the arrival of the more complex vertebrates, arthropods, molluscs, and annelids, organisms were very weird structurally, but had relatively simple ecological niches. They were mostly filter-feeders, bottom-feeders, and very occasionally were limited predators. The first two niches will largely be influenced by fundamental mechanics, such as surface area-volume and organ systems. Furthermore, we want to make sure the player has a grasp of their basic macroscopic mechanics before throwing them to super-predators.
Progression Pipelines - I think there will generally be two “game progression styles” in the early macroscopic/late multicellular stages, which I informally/affectionately nickname the “Thrivian Jelly Pipeline” and the “Thrivian Worm Pipeline”. The Thrivian Jelly Pipeline covers clades like that of the ctenophora and the cnidarians, while the “Worm Pipeline” covers everything else. The Jelly Pipeline is more limited in progression, as most advanced organisms evolved from worm-like organisms; as such, it’ll act as a unique playstyle. The worm pipeline is likely more standard to most Thrive playthroughs, and more directly proceeds to more advanced morphologies. The two aren’t necessarily mutually exclusive by the way, but the more Jelly-Like you are, the harder it is to evolve advanced structures in your body plan.
Scope Limits - I think there are two things that we should declare not to incorporate within Thrive now unless implementation is very simple, and a third thing we should really think about. First, colonial macroscopic organisms, as these are a very niche and complex cases. Second, complex endoparasitic organisms, as it would be a nightmare to represent a microscopic representation of the inside of another organism. Third, we should really put some thought into the various scales we will represent. There will undoubtedly be times were we will have to cut between various “scales”, such as in microscopic multicellular organisms to the macroscopic world, and omit certain niches or organisms. Where will these cuts occur?

This post focuses on the “Thrivian Worm Pipeline”. I try to give a broad description of various clades, and infer some basic parts or mechanics we can implement into Thrive. As such, most of this will be focused on the early parts of the late-multicellular, probably before the playthrough’s “Cambrian Explosion” where more advanced morphologies appear.

By the end of this post, hopefully you guys understand what I mean, and hopefully we will have a slightly clear understanding of how we can define our scope for the early macroscopic stage.

Going through this has made me believe it is actually very feasible to represent a good amount of diversity with a large, but realistic amount of effort. I hope you guys emerge with the same feeling, and I promise that I will begin focusing on more immediate concepts soon again!

SIMPLE BILATERANS AND THE “WORM PIPELINE”

Xenacoelomorpha

Xenacoelomorpha are triploblastic and bilateral, meaning they are able to develop muscle-derived and more specialized organ systems, and are bilaterally symmetrical. They do not have a complete digestive system (their mouth filters both food and waste because they don’t have an anus).

There are two major clades within Xenacoelomorpha…

Acoelomorpha
Xenoturbellida

Xenacoelomorpha probably serves as the representation of what most macroscopic animals in Thrive will look like only a bit before they start specializing into more unique organisms. They don’t really have any unique characteristics to implement.

Xenoturbellida

Containing roughly 6 species within the same genus, Xenoturbellida represents a very small group of animals. I don’t think there is much we can derive from this clade. They notably have a mouth opening on the bottom of their body rather than on their anterior side. Above is a Xenoturbellida that looks like a churro; most Xenacoelomorpha look a lot like this, except less churro-esque.

Implications for Thrive

Churros. Having the ability to customize where a mouth part is placed would be an interesting characteristic for more simple organisms. However, if that interferes with the future parts of the multicellular stage with a more defined head and mouth at front of body, then that takes precedent.

Acoelomorpha

There are roughly 350 Acoelomorpha, representing a decently-sized clade. Being rather small animals, most of them registering on the centimeter range, they generally live either planktonic lifestyles or slither around on the benthic floor. A few of them have very simple sensory organs called ocelli, among the simplest of metazoan eyes. Above are mint-sauce worms, an example of Acoelomorpha.

Notably, some Acoelomorpha are able to integrate photosynthetic plankton within their epidermis via consumption. This allows them to benefit from photosynthesis; some of these organisms depend completely on their symbionts.

Implications for Thrive

As said above, there likely isn’t much to extract from Acoelomorpha; they just serve as a representation of what most players will somewhat look like at some point in their playthrough.

A unique ability we can implement is to get some photosynthetic capability from the food you eat. This would have to be balanced in some way to make it so that only very simple organisms with very thin membranes can possibly benefit from this adaptation. For example, reducing temperature tolerance ranges and health could work.

So, I guess the breakdown for this group after simple mechanics are implemented involves…

Implement a capacity for the player to absorb the photosynthetic ability of what they eat if they have sufficient adaptations. I would think this would be more of a bonus trait rather than a core requirement in terms of mechanics.

SPIRALIA - MORE ADVANCED WORMS AND MOLLUSCS (Not Covered Here)

From here, we can discuss Spiralia, a large group of metazoans including some more complex organisms worthy of attention.

Platyhelminthes - The Flat Worms

The flatworms. Triploblastic and bilateral, flatworms have no true body cavity, resulting in a rather simple body plan. They display cephalization (they have a true head) and have a more developed nervous system, though they don’t have a complete digestive system. Their high surface area allows them to circumvent the need for a elaborate respiratory or circulatory system, relying mostly on their digestive system for circulation. Most are rather small (the millimeter range), though some are rather visible benthic animals. Their mouth notably is found near the bottom of their body, which looks somewhat like a proboscis. This mouth can extend in some species, though not to a significant amount.

There are two major groups of platyhelminthes: the Catenulida and the Rhabditophora. The Catenulida have been rather difficult for scientists to distinguish due to their relatively small number of species and their similar morphology; meanwhile, the Rhabditophora are the more “iconic” species of flatworms. Rhabditophora include the notorious tapeworm, and many other parasitic species.

Implications for Thrive

To me, the flatworms represent another point in the “basal worm pipeline” that most players will likely end up a part of as they become more advanced organisms. They represent a “step-up” in terms of Thrive progression, with the advent of a more advanced digestive and nervous system. I think organisms such as these will emerge naturally in Thrive without the need to implement unique mechanics, and thus, gameplay for these sorts of organisms will depend on the fundamental game mechanics shared by all macroscopic organisms. I notice that this is a trend with many of the most basal, early-multicellular organisms - so we might want to pay attention to creating simple, but fun mechanics for the early stages of the late-multicellular stage.

I will say though that flatworms can be very colorful, so having nice customization options could be seen as a bonus for this clade. And of course, being able to “flatten” the metaball body plan of soft-bodied organisms would help visually represent these organisms as well.

Nemerteans - the Ribbon/Proboscis Worms

Nemerteans uniquely have a proboscis. This projectile proboscis can rapidly extend, capturing prey items and increasing surface area. They are rather similar to flat worms - however, they have a complete digestive system (the presence of an anus) and a closed circulatory system, representing one of the most basal organisms to develop such features.

The two major groups of ribbon worms include the Enopla and the Anopla. The most distinguishing feature between these two groups revolve around the presence/absence of a “stylet” in their proboscis, which essentially is a sharp needle-like structure. Enopla have stylets; they sometimes utilize it to grasp prey.

Implications for Thrive: Another point in the Thrivian “worm-pipeline”, nemerteans can be adequately represented with what has been discussed above upon implementation of a proboscis…

Implement proboscis.
Allow customization of proboscis. An “unarmed” proboscis can completely consume small-enough prey, but is rather useless against larger organisms. An armed proboscis can grab and inflict damage on larger prey items, but does less damage.
Armed proboscis can be imbued with toxins.

Gnathifera - Jawed Worms

A larger clade rather than a phylum, this group contains many smaller clades. I think it’s worthwhile to discuss these organisms as a whole before individual diving in. Gnathifera all display various forms of chitin-derived mandibles. These mandibles come in various forms and perform various functions. As such, the most basal feature which can represent the jawed worms in Thrive is…

Implement simple, chitinous mandibles as a very basal jaw structure.

Diving into each individual phylum of the Gnathifera will help us see some customization options for these jaws. We can’t really go into much depth here without a larger discussion of how mandible customization will work however, so this will likely be a rather brief section.

Chaetognatha - Arrow Worms (Gnathifera)

Placement of these organisms is a bit dubious within Spiralia, but these organisms represent a large percentage of planktonic biomass despite a relatively small number of species. These are very active predators, using their mandibles to prey on smaller organisms. They appear to be a very ancient bilateral phylum.

Arrow worms notably have bristle-like fins on the side of their body which lets them rapidly accelerate, though they do not have endurance. Many of them utilize the same toxins utilized by pufferfish in their bites. Arrow worm mandibles can likely be implemented with dedicated mandible customization. Implementing toxin capabilities to these basic mandibles should cover the rest.

Implementing mandible customization. This would likely represent the advent of the arthropod-esque playstyle in Thrive, so it is a needed feature anyways.
Implement basic fin customization for basal body plans. A lot of the uniqueness of the fins of arrow worms is their “cosmetic uniqueness”, so if it’s too hard to graphically represent such a feature without labor, it’ll worthwhile to skip.

Gnathostomulida - Lesser Jaw Worms (Gnathifera)

Gnathostomulida were recognized as an individual clade in the late 1960’s. They are a rather small group of organisms, and are also small in physical size. I don’t these organisms require a unique mechanism to be represented in Thrive as long as other fundamental systems are implemented. If anything can be jotted down…

Jaw customization feature which allows organisms to “scrape” organic material off the ocean floor. There have been prior discussions about this, as this will serve as one of the first methods of gathering food available, so this should be implicit to the late-multicellular stage itself.

Rotifera - Wheel Jaws (Gnathifera)

Among the most numerous organisms on today’s Earth, Rotifera are most known for their jaws, which allow suction akin to cilia in Thrive.

Most rotifers are tiny, meaning their suction ability might not be adequately represented in Thrive at the macroscopic level if we must concede some scales of detail. As such, it might not be worth discussing this clade currently.

Brachiopoda - Asymmetrical Clams

Will not cover now; sessile gameplay and unique feature (clams)

Phoronida - Sessile Filter-Feeding Worms

Will not cover now; sessile gameplay

Bryozoa (Ento & Ectoprocta) - Colonial Filter Feeders

Will not cover; colonial gameplay probably outside scope of Thrive

Annelids - Segmented Worms on Crack

The annelids are an incredibly large and diverse group of animals known for their segmentation and relatively complex organ structures. They include leeches, earthworms, beard worms, and many other organisms. All are soft-bodied and have a complete digestive system, as well as a pair of nerves running throughout their body. They all have closed circulatory systems and features analogous to hearts.

Most annelids have setae, which are essentially tiny extensions throughout the skin of the organism. In some marine annelids, setae can look a lot like limbs, allowing benthic dwelling. For other annelids, such as the earthworms, setae are miniscule and assist with digging. Most annelids are detrivores, though some display predation and more active dietary habits.

I think annelids can largely be represented in Thrive as being the final, most complex form in the Thrivian “worm-pipeline”. Annelids have many diverse functions and forms, so allowing players creativity in customization their soft-bodied, wormlike organisms is the best way to approach this clade of organisms without killing ourselves.

It’ll be worthwhile to address annelids phylum by phylum, but here are some traits ubiquitous to most that can help distinguish annelid-like organisms from other Thrivian organisms. A lot of what distinguishes annelid phylums from other phylums are variations in the below features anyways:

Segmentation. This will likely be a fundamental editor mechanic for soft-bodied and arthropodic organisms which distinguishes them from vertebrates.
Setae, which can assist with burrowing or act like legs. Perhaps setae can be the simplest and first available limbs.

Polychaeta - A somewhat dubious grouping of largely marine segmented worms that are known for their distinguishable setae protrusions. Include the sandworms, bobbit worms, sea mice, and many other notable annelids.

Because these organisms are very diverse, allowing decent setae customization is probably the best way to represent them. Some setae can be longer and have greater surface area, allowing swimming. Other setae can be shorter and can allow for crawling or burrowing. Other setae can have poison on them, and can serve as a defense mechanism.
Several unique organisms here have features which overlap with other groups of organisms, such as jaws and burrowing.

Oligochaeta - A somewhat old-school grouping of Naididae, Aeolosomatidae, and Lumbricidae. Aeolosomatidae and Naididae are microscopic, and are outside of the scope of this document for now. Lumbricidae include 6000 species of earth-worms. This group of organisms will likely be represented in the switch to land. They depend on a mucous layer, as well as damper conditions, to remain moist.

This group would likely be represented only when movement to land is implemented, which is in the distant future.

Hirudinea - The leeches. Implications for this group are pretty obvious, and will likely be the most defined and feasible “parasitic” niche in Thrive.

Implementing an ability for simple jaws and proboscis to have a parasitic ability, allowing hostile resource transfer but minimizing opportunity to consume organic matter whole.

Annelids are honestly an entire beast of a clade to tackle, and will likely deserve their own post later similar to the other more complex organisms in the multicellular/aware stages. However, this provides a general overview that gives us rough ideas. I still stand by my statement that annelids represent the “pinnacle” of the Thrivian worm pipeline.

Priapulida

No.

Nematoda

Will not cover now due to microscopic scale. If nothing else, nematodes will likely serve to be microscopic food for filter-feeders and bottom-feeders.

Dicyemida

Will not cover now due to microscopic scale.

Orthonectida

Will not cover. Endo-parasitic nature likely outside of the scope of Thrive.

Kinorhyncha

Also known as mud dragons, this group of animals will likely be represented by the fundamental mechanics of the late-multicellular and aware stages. They are known to be able to burrow.

Look at that; in what we covered, we have addressed a great deal of metazoan diversity already! Here is a list of all features covered.

List:

Surface-Area to Volume Ratio - This will be a very definitive feature of the early macroscopic stages, defining filter-feeding and buoyancy for organisms which do not have much morphological complexity. It will also directly feed into the metabolism of organisms, having direct influence on circulation, digestion, and respiration. Will become less important as organisms develop more advanced and thick skins, though will always have an effect. Individual discussion.
Organ System - The fundamental feature shared by all organisms. Will most correlate to progression, and will serve as the basis of metabolism for organisms. The late-multicellular stage will represent the advent and acquisition of initial organ parts, allowing players to get familiar with the system as a whole.
Mesoglea - Representing Cnidarians and Ctenophora, this will represent an immediate way for organisms to increase buoyancy and float, but will make it difficult to evolve advanced organ or membrane structures.
Nematocyst/Celloblast Appendages and Customization - Representing Cnidarian and Ctenophoran appendages. Have limited control and advancement, but allow for basic grappling, filter-feeding, and stinging.
Surface-Area/Volume Increasing Appendages - This appendages will be simple ways to increase surface area or volume, thereby increasing specific characteristics. Will be especially important in the early macroscopic stages, but less important as SA:V becomes less important. Will provide customization and flair options.
Easy Access to Bilateral Body-Plan - This will represent the “worm” body plan, and will be the basal body plan for more complex organisms. Probably a discussion of how the editor will look in general.
Burrowing - An important feature for more advanced playstyles. Should probably be discussed later.
Proboscis and Customization - Probably the simplest mouth part to be offered to the player. Allows for bottom-feeding, as well as some hostile resource transfer, filter-feeding, and limited predation
Basal Mandible/Mouth Customization - Requires its own discussion later in all likelihood.
Basic Fin Appendages - Requires its own discussion later in all likelihood.
Segmentation - As discussed in earlier posts, segmentation would likely be represented as an inherent part of the body plan/metaball editor. For certain organisms, players can group metaballs together to form a “segment”, which will be important for arthropods especially. Likely requires its own discussion, though mechanisms wouldn’t be that influential in soft-bodied organisms and basically non-existent in vertebrates.
Setae And Customization - Represent more advanced limbs with diverse functions, allowing swimming, crawling, and digging.
Bioluminescence - A notable feature of various worm-like organisms.

Doesn’t sound too bad when put like this, right? A lot of organisms can probably be represented with a combination of various organisms if we offer a decent amount of customization.

Images are important, but I didn’t want to spam them throughout the entire post as that could hurt readability. Here are images of various organisms.

Ctenophora

Scyphozoa (Cnidaria)

Cubozoa (Cnidaria)

Hydrozoa (Cnidaria)

Xenoturbellida (Xenacoelomorpha)

Acoelomorpha (Xenacoelomorpha)

Platyhelminthes - The Flat Worms

Nemerteans - the Ribbon/Proboscis Worms

Chaetognatha - Arrow Worms (Gnathifera)

Gnathostomulida - Lesser Jaw Worms (Gnathifera)

Polychaeta (Annelids)

Oligochaeta

Hirudinea

These organisms didn’t have a description for various reasons, but I’ll list them here still.

Brachiopoda - Asymmetrical Clams

Phoronida - Sessile Filter-Feeding Worms

Bryozoa (Ento & Ectoprocta) - Colonial Filter Feeders

Rotifera - Wheel Jaws (Gnathifera)

Priapulida

Nematods

MirrorMonkey2 · December 21, 2023, 3:34pm

Very evocative and sensible post. It does a good job of not making the early multicellular stage seem like an impossible thing to implement, but rather like a huge but doable task.
Since gameplay at various scales is one of the principle topics regarding the 3D stages from a graphical perspective, I wanted to ask you some more about these statements:

Which scales would you have in mind when thinking about scales which can possibly be omitted? Are you mainly thinking about a jump in scale that happens immediately after the 2D-3D transition or do you think there are other gaps afterwards which you would consider?
Personally, I’m in favor of making the transitions from scale to scale as smooth as possible. But I’m aware that this will be an issue which will be determined to a large extent by the technical possibilities.
I’m inviting you all to branch out the discussion about the technical and graphical aspects of this consideration of scale into this thread: https://forum.revolutionarygamesstudio.com/t/depicting-the-3d-environment/888https://forum.revolutionarygamesstudio.com/t/depicting-the-3d-environment/888
This way we can keep the discussion in this thread more focused on the editor and organ progression.