User report from the MP/cavern session: the canopy frame rendered flat light
gray -- unlike the dark frames in the polar exports. Root cause: the frame
colour was routed through the LIT material path (Diffuse+Ambient), so it
multiplied with each map's lighting -- polar's dim purple light happened to
look right, cavern-night's ambient 0.8 washed it out to gray.
The canopy is unlit interior structure: the frame batches now go through the
renderer's pure-emissive UNLIT branch (black diffuse + emissive = the frame
colour), constant on every map. The exact original value is not recoverable
(texture-less ramp = no texel luminance to index); default (0.13,0.12,0.15)
[T3] matches the near-black frame in pod gameplay footage.
BT_COP_FRAME="r g b" overrides; BT_COP_RAMP_L retired.
Verified: cavern-night and polar-day now show the identical dark frame.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
