Tile3DLayer with i3s loader appears too dark after adding ambient light

[Muromi-Rikka]

Description​

When using Tile3DLayer with the i3s loader in deck.gl, the 3D buildings appear excessively dark even after adding ambient light settings. The scene lacks proper lighting balance, making it difficult to visualize details in shadowed areas.​

Environment​

• deck.gl version: 9.1.12
• i3s-loader version: 4.3.3
• Browser: Chrome

Expected Behavior​

After configuring ambient light, the 3D models should have balanced illumination, with shadows that enhance depth without overwhelming visibility. Ambient light should supplement direct lighting to improve overall scene visibility.​

Actual Behavior​

Buildings remain disproportionately dark, almost as if ambient light is not being applied correctly. The scene appears underexposed, and surface details are difficult to discern. This issue persists even when increasing the ambient intensity value beyond typical ranges.