1. Optimize the Rendering Pipeline (The Biggest Win)
Use Forward+ or Mobile Renderers: Use Forward+ if targeting high end PCs. For lower end hardware, Steam Deck, or Nintendo Switch, the Mobile (Vulkan) renderer provides a massive performance boost by sacrificing high end features like automatic screen space reflections.
Consolidate Viewports for Split Screen: If using split screen, remember that every player viewport multiplies the draw calls and geometry processing by 4. Use Viewport Scaling (Viewport.scaling 3d scale) to drop the internal rendering resolution to 0.7x or 0.8x while keeping the UI crisp.
Share a Single Camera (Shared Screen): If your game style permits a shared screen format (like Overcooked or Diablo), use one camera that dynamically adjusts its zoom and position based on a bounding box containing all 4 player positions. This avoids multiplying your draw calls entirely.
2. Radical Mesh and Texture Management
Aggressive Mesh LOD (Level of Detail): Godot 4 generates automatic mesh LODs on import. Ensure this is enabled. For a 4 player game, distant assets must drop to low poly versions immediately to keep the vertex count manageable across multiple screen perspectives.
Vram Texture Compression: Ensure all textures use VRAM Compressed format on import (ETC2/ASTC for mobile/handhelds, BPTC/S3TC for PC). Never leave textures uncompressed, as texture memory bandwidth will choke 4 simultaneous views.
Occlusion Culling: Bake an OcclusionModel3D for static level geometry. This prevents the engine from rendering objects that are completely hidden behind walls, which is crucial when 4 different players are looking in different directions.