The WebGL refraction pass that draws refract_data glass over the emissive data
(spec MESH_PHYSICAL_MATERIALS §3.4 Phase 3). Construction-time, not a persisted
user setting: the panel has no control for it.
Resolution of three's transmission target relative to the frame, in (0, 1],
applied ONLY during that pass. Phase 2 glass keeps three's default 1.0; WebGPU
has no equivalent knob.
Rendering controls configuration