Lamia & Segmented Entity System

[VMSolidus]

About the PR

This is a draft PR for an upcoming new playable species, the Lamia. Lamia are an older species from the 2022 era of Nyanotrasen, and were previously abandoned code that was dropped from the game on October 13th, 2022. I was able to locate what I believe to be the last remaining branch containing Lamia, from a defunct server repository that ran an October 12th, 2022 build of Nyanotrasen. Thus I began a project to refurbish this code for use on modern SS14.

The Lamia I wish to PR are only recognizable from the original Lamia in that they share the Tail Segment System. That is, they prominently feature a completely unique mechanic whereby their body is composed of multiple entities linked together in a chain. The original version of this code had a great many bugs related to the game's physics system, and it was severely limited by the Robust Toolbox engine at the time. In the year since Lamia's abandonment, Robust Toolbox has gone through many iterations and improvements, and has deprecated large parts of the physics system that old Lamia utilized.

Redesigns from the original 2022 Lamia, AKA Nyanotrasen Lamia. Vs. DeltaV Lamia

The original Nyanotrasen Lamia were made with several limitations in mind. Their size was heavily restricted by the physics engine at the time, we aren't beholden to that same limitation anymore. Thus DeltaV Lamia are vastly larger than the Nyanotrasen Lamia, featuring a tail that is 5 tiles in length, with fully functional physics collisions. They were also not able to wear Hardsuits due to limitations of the SpriteComponent, and thus were instead designed around having a "Barotrauma resistance". On DeltaV code, we can arbitrarily state that species use different optional sprites for items, therefore its possible to have for example a Nukie Hardsuit, with its equipped-outerwear state, equipped-outerwear-lamia, equipped-outerwear-lamiainitialsegment, equipped-outerwear-lamiasegment, and so on. The Lamia Segments can simply state that if they equip a hardsuit, they utilize the -lamiasegment sprite option. Therefore its no longer necessary to create an entire new item solely so that snakes can wear a hardsuit.

Positive Traits

• Extreme Size. Lamia are 5 tiles long, and weigh as much as a car. They make a mockery of mass contests, and they can push physics objects around simply by slithering into them.
• Significantly larger health bar. A Lamia is put into critical condition at 200 damage, and dies at 300 damage. This is offset by the Lamia having a certain percentage of damage taken by the tail transferred to the main body.
• High resistance to forced movement. Space Wind at standard pressure cannot move them.
• Unusual hybrid damage melee via their Hypo-Fangs. Lamia bite attacks deal 1 point of armor piercing, 2 points of poison, 2 points of asphyxiation, and inject 3u of Space Drugs. Planned traitor items exist that add a fillable chemical reservoir that they can inject into people with their attacks.

Negative Traits

• Extreme Size. Lamia are literally the size of a, "Broad side of a barn". A blind person could throw a rock, and still hit the Lamia. By extension its essentially impossible for a Lamia to evade attacks. Yea you can take hits, but you're also going to take hits. All of them.
• Paramedics WORST ENEMY. Since they weigh as much as a car, even Oni struggle to drag them. Even a rollerbed only slightly helps drag a Lamia around.
• Vulnerability to AOE damage. An explosion that simultaneously strikes a Lamia's entire tail, plus their body, will deal double damage.
• Cannot wear shoes. Although not being able to wear magboots is also offset to their natural high resistance to space wind.
• Extreme size also means Lamia are functionally uncloneable. They require 770 units of Biomass, the equivalent of 5.5 Onis, in order to be cloned.

Why / Balance

This PR is part of an ongoing project to add exciting new content to the DeltaV repository, with a focus on keeping the theme of "Monster People" species, per request by admins.

Technical details

The code regarding Tail Segments is actually unfinished, and still needs significant overhauling before this PR can be undrafted. Here's a few concerns:

• Implement "Marking Parity"
• Make/Commission/Request new markings for the Lamia and her tail segments
• Implement "Hardsuit Appearance Parity"
• ServerLamiaSystem now utilizes new physics engine options.
• "We need to be able to spawn 80 Lamias without slowing down the server -Debug", this is a hard requirement. Having 32 tail segments is not required. I would prefer that we have 32 tail segments, but if we optimize their code for performance and still find out we aren't meeting the 80 Lamia hard requirement, I am willing to reduce them to as low as 16 to 20 segments.
• Implement Wizden's upcoming "Shoot Over Corpses unless they're targetted" for Lamia Tails.
• Reimplement the mechanic for Segments sharing their healthbar with the Lamia.
• Possibly make it so that Lamia can only wear Jumpskirts? I'd want to outright get rid of the layer mask if possible.

Non-Technical TODO list

These are all the TODO's that don't necessarily involve C#, and primarily live in the YAML side of things.

• Implement marking customization for Lamia. They should have marking variations for More/Less humanlike versions. Such as a Snake Head(We can re-use the Lizard snake head), Medusa Head, changing how far up the scales go, and if the Lamia has human skin or full scales. I'd like to have tail pattern variations that can be set in the character customization, but that is also pending the VisualizerSystem for tail segments.
• Make their hardsuit variants. Not actually difficult, just takes some time.
• Finely tune their numerical values. Basically nothing on the YAML side of things is final, and is subject to change pending beta feedback and/or testing.

Media

One of the downsides of having extreme mass.

Working Collision physics:

Finalized version of the damage system, also featuring significant improvements to the tail systems.

Changelog

🆑 VMSolidus, @Elijahrane, and @noctyrnal

• add: Lamia have been added to the game as a new playable species! They are currently extremely buggy, and so are by default disabled as a roundstart species. To enable them for (Buggy) playtesting, go to /Species/lamia.yml, and set roundstart to true.

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[Remuchi]

I did c# review. It's... fine? Can't go through yaml yet.

[Remuchi]

eh

[Remuchi]

Suggested change

[Remuchi]

eh

[Remuchi]

Suggested change

	namespace Content.Shared.SegmentedEntity;
	public sealed class SegmentSpawnedEvent : EntityEventArgs
	namespace Content.Shared.SegmentedEntity;
	public sealed class SegmentSpawnedEvent : EntityEventArgs

[Remuchi]

Suggested change

	/*
	* Delta-V - This file is licensed under AGPLv3
	* Copyright (c) 2024 Delta-V Contributors
	* See AGPLv3.txt for details.
	*/

[Remuchi]

Suggested change

	}
	private void HandleDamageTransfer(EntityUid uid, SegmentedEntitySegmentComponent component, DamageChangedEvent args)
	}
	private void HandleDamageTransfer(EntityUid uid, SegmentedEntitySegmentComponent component, DamageChangedEvent args)

[Remuchi]

Suggested change

	if (args.DamageDelta == null) return;
	if (args.DamageDelta == null)
	return;

[Remuchi]

merge into one return

[Remuchi]

Suggested change

	if (args.RayCastResults == null) return;
	if (args.RayCastResults == null)
	return;

[Remuchi]

Suggested change

	}
	args.RayCastResults = entityList;
	}
	args.RayCastResults = entityList;