I'm trying to get my head around the functionality that allows lights to only illuminate certain meshes - namely using includedOnlyMeshes and excludedMeshes . And I seem to have run into a problem which hopefully you can see with this playground example Lights The example has two spheres, sphere(centre screen) and sphere2 (right side). Down the script four lights are set up and there are some marked lines of code for "turning off" the red and green lights for the centre sphere. The red light is "turned off" by using this line of code: light0.includedOnlyMeshes = [sphere2];which tells the red light to only illuminate the sphere2. Seems to work fine I then try to turn off the green light on the centre sphere with this line of code: light1.excludedMeshes = [sphere];which tells the green light not to illuminate the centre sphere. It does not work So is it my code or has something changed in BJS with the addition of "includedOnlyMeshes"? Any help appreciated before I pull out all my hair cheers, gryff