Objective

Design and implement the matter crate to define material behavior in LP's physics simulation while balancing emergent properties with computational performance.

Current Challenge

The matter crate structure exists but remains empty due to a fundamental design decision between:

• Emergent approach: Materials emerge from fundamental properties (realistic but computationally expensive)
• Hardcoded approach: Define material behaviors explicitly (performant but artificial)
• Cellular Automata approach: Grid-based rules like Powder Toy/Noita (performant but grid-limited, doesn't leverage PBMPM's particle advantages)

Implementation Considerations

Why not Cellular Automata:

• Grid-based limitations don't suit LP's continuous physics goals
• PBMPM provides superior fluid dynamics and material interactions
• Cellular automata feels too constrained for realistic material behavior
• Would waste the investment in PBMPM particle physics

Dependencies:

• PBMPM physics integration (Position Based Material Point Method (PBMPM) Integration for Unified Physics System #76)
• Energy system integration for temperature effects
• Performance constraints for real-time simulation

Potential Approaches:

• Property-based emergence from fundamental forces
• Hybrid system with basic types that interact and transform
• Simplified chemistry abstraction without full molecular simulation

Technical Notes

Limitations:

• True molecular simulation not feasible for real-time gameplay
• Abstraction level must balance emergence with performance
• Implementation depends on PBMPM capabilities

Future Considerations:

• Start with basic material definitions and evolve toward emergence
• Integration with climate system for realistic phase transitions
• Performance testing required to determine feasible complexity level