Currently, there is a known issue in Twinmotion where lights may appear to leak through walls. This can affect the realism of your scene, leading to unintended lighting artifacts.

Here are a few things you can try to mitigate this issue:

1. Adjust Shadow Quality in Preferences

The overall quality of shadows in Twinmotion can be adjusted by following these steps:

• Go to Preferences > Quality > Shadows
• Set this to Ultra

This may resolve some light leakage issues, but it may not eliminate them entirely.

2. Improve Shadows in Scene Settings

To further improve shadow rendering, follow these steps:

• Navigate to Scene > Ambience > Render > Shadows
• Change the shadow setting from Standard to Accurate

This adjustment is available starting from Twinmotion 2025.1 Preview 2 and can significantly reduce light leaks in your scene.

3. Modify Shadow Bias (For Standard Shadows)

If you are using Standard shadows, decreasing Shadow Bias can help reduce light leaks. However, please note that this may introduce other issues, such as shadow acne, which can affect the visual quality of your project.

The following images illustrate the differences between Standard and Accurate shadow settings while using High Quality rendering in Twinmotion.