Shadow Culling

Introduction

Any entity (item, structure, character) in your field of view that is completely occluded by shadow will be culled, so these things will not be rendered where you cannot see them. This reduces CPU and low-end GPU load, and the performance improvement is even more significant in item-heavy enclosed spaces and at long distances.

Usage

Follow the installation steps to enable LuaCsForBarotrauma and allow it to run C# scripts. The mod is client-side only and plug-and-play.

Configuration

You can adjust optimization options in the Mod Gameplay Settings in the main menu to improve performance and effect.

Test Example

Display refresh rate: 60 FPS, V-Sync on. Using this submarine [noparse][LK]Vs.Swk-Solifugae 20260520[/noparse] as the baseline for performance comparison, the scene contains as many as 3000 structures. Checking with the console command showperf reveals that BackCharactersItems consumes a large amount of performance, and almost all of this overhead comes from structure DrawCalls.

When LOS mode is enabled , even though many structures are not visible, they still issue DrawCalls, causing unnecessary performance overhead. In the Draw stage, the measured time is 9.64ms/tick. When the total Draw + Update time exceeds 16.67 ms/tick, the game starts to laggy.

When Shadow Culling is enabled, only visible structures issue DrawCalls. In the Draw stage, the measured time drops to 3.32ms/tick, but this is an exceptionally good result achieved only under extreme conditions.

Technical Notes and Known Issues

1. This mod was developed with AI assistance. The code has been strictly reviewed by me, and no serious issues have been found so far.

2. Most of the performance overhead of "Shadow Culling" is not caused by the culling algorithm itself, but by optimizing the drawing process through patches.

3. When you see plant seeds (or items inside any container) being culled, or objects at the edge of the screen being unexpectedly culled, this may be a pre-existing issue in vanilla. For details, refer to issues #17490 and #17419 in the Barotrauma GitHub repository.

A friendly tip unrelated to this mod

I strongly recommend that you keep V-Sync enabled (the game's default setting) and set your display refresh rate to the lowest acceptable value (60 FPS recommended, matching the Update rate). This is because the game is essentially single-core: the Draw and Update stages run on the same thread. When the Draw frame rate exceeds the Update rate, in the worst case Update has to wait for an another full Draw to complete before stepping to the next frame, causing 1% low of the Update stage to drop sharply and the game to unstable lagginess. Inflated frame rates will not give you a truly smooth experience. *

Extra Keywords: Performance | 性能 | Optimization | 优化 Github Repository