Understanding MeshTransmissionMaterial Reflections

Based on the information available, I can provide some insights about the reflection issue you're experiencing with MeshTransmissionMaterial.

Why the Green Plane is Reflecting

The MeshTransmissionMaterial is based on the MeshPhysicalMaterial in Three.js, which naturally has reflective properties. When you place a transparent material with transmission properties in your scene, it will reflect objects in the environment (like your green plane) based on its material properties.

Possible Solutions

1. Adjust transmission properties: You can try modifying the transmission-related properties to reduce reflections:

   • Lower the roughness value to make the material less reflective
   • Increase the transmission value for more transparency
   • Adjust the ior (Index of Refraction) value

2. Modify the transmissionResolutionScale: As noted in the documentation, you can adjust the transmissionResolutionScale property of your renderer:

JAVASCRIPTCopied
renderer.transmissionResolutionScale = 0.5; // Lower value for better performance

3. Layer management: Consider organizing your scene layers so that certain objects don't contribute to reflections in the transmission material.

4. Environment map control: If you're using environment maps, you might need to adjust or disable them for this specific material.

Without being able to directly examine your sandbox code, these are general recommendations based on how MeshPhysicalMaterial (which MeshTransmissionMaterial is based on) works in Three.js.

I recommend experimenting with these properties to find the right balance for your specific scene setup.