Muffin

Muffin is a top-down, 3D pixel art, action RPG using 2D sprites, developed in C#/Unity. I worked on it in 2022/23 with the goal of learning about game/physics engines, and improving my skills in C#, 3D, shaders, render pipelines, traditional AI design, and many other topics.

The game is in a pre-alpha stage. It is fully playable but is not feature complete and only has about 5 minutes worth of content. However, it is considered complete as this was a learning project and I have no intention of turning it into a releasable game.

This repo only contains the C# scripts and no other files or assets related to the game. Plastic SCM was used for full version control for this project as it natively integrates with Unity.

Some technical features

• Unified, hierarchical state machine AI model that powers friends and foes alike and allows them to interact with one another
• Faction management that allows changing NPC behaviours real-time (towards player and other NPCs)
• (I also experimented with a behavioural tree model for AI which is in this repo but not used as it was not required)
• Equipment is swappable in real-time using scriptable objects (any range type weapon is is supported, extendable to melee)
• 4 directional player sprite movement while maintaining full 360 degrees, free mouse-controlled aim
• Object pools to pre-spawn a number of frequently spawned objects
• Universal Render Pipeline post-processing features, incl. bloom, depth of field, color grading and more
• Pixelise render feature/pass for a consistent pixelated look of all in-game elements, except UI elements
• 2D dynamic lightning (e.g. zone based), cloud shadows, etc.
• Extensive use of shaders to simulate water, fog, sprite lightning, and more
• Basic 3D modelling of rocks, crates and other objects
• Cinemachine with camera zones and target groups to enable look-ahead
• Scalable quest and dialogue system (allowing for 4 quest types) incl. UI (using Inky for dialogue scripts and variables)
• Unity Terrain and GPU instancing for grass/flower sprites
• Timeline-powered intro and on-scene-change cutscenes which are skippable
• A small but rich game worked with grass/trees swaying in the wind, dynamic lighting/shadow effects, fireflies, birds, and marine life such as schools of fish and nautili

Game system examples

NPC state machine

• NPC state machine is at the core
• NpcBehaviour sets default behavior: anxious, neutral, indifferent, observant, defensive, or aggressive
• NpcMovement sets default movement type: wander, patrol or idle
• Combination of AnimationController and AudioController allow customising the visual appear and audio (humanoid and two-legged dinsaur implemented)
• Separate, optional Game Objects with sphere colliders determine:
  1. Awareness: trigger intermediate action such as observing
  2. Action: switch from default movement to default behaviour
  3. Collaboration: support others of same faction or flee together
  4. Interaction: allow player to interact e.g. trigger dialogue
• FactionIdentity component determines which other factions the NPC is hostile, friendly or neutral towards
• Factions can change at runtime
• HealthManager determines health and triggers disabling of NPC class
• AttackController determines damage, range, etc.

Quest system

• A Quest is a collection of tasks which can be linked to a story
• Stories are text assets which are arranged into a flow using the third party tool Ink
• C# classes share data with Ink through DialogueVariables, allowing dialogue to influence game behaviours and vice versa
• The system supports any task types such as "reach location x", "defeat x number of type y enemies", or "do x"
• The active quest, its task and their states are shown on the in-game UI to the player
• Quest states and dialogue variables (which include story progression) are, by default, saved on scene change