Real time Wind System for Unreal Engine's Open World Game

Project Overview:

• The project focuses on implementing a real-time wind simulation in a 3D open-world game called Veloren.
• The main research question is about the performance cost of such a simulation in terms of frame rate.

Wind Simulation Algorithm:

• Based on Jos Stam's method for solving Navier-Stokes equations.
• Uses a grid-based approach with steps including adding sources, diffusion, advection, and projection.
• Designed to be stable and fast enough for real-time use, focusing on visual results over physical accuracy.

Key Design Considerations:

• Grid size: Affects spatial resolution and performance.
• Simulation frequency: How often the entire simulation is updated.
• World boundaries: Handling edges of the simulation grid and interactions with objects.

Performance Evaluation:

• Measured using the Unreal Insight profiling tool.
• Main metrics: Mean and median FPS, percentage of total server time.
• Tested various grid sizes and two simulation frequencies (once per tick and once per second).

Current Limitation:

• Server-side: Performance cost increases with grid size, especially when run every tick.
• Running simulation once per second significantly reduced performance impact.
• Client-side: No significant performance impact detected.
• Lower simulation frequency resulted in less smooth wind behavior from the player's perspective.
• Challenges and Limitations:
• Grid size significantly affects performance due to the nature of the algorithm.
• Trade-off between simulation accuracy/smoothness and performance cost.

Future Work and Potential:

• Optimizations like splitting the update process or using asynchronous updates.
• Interpolation for smoother transitions at lower update frequencies.
• Potential for new gameplay features like sailing ships, improved particle effects, etc.