The user caught the inversion (blocked viewports, see-through frames); the
answer came from the rasterizer board itself: an i860 disassembly of the
VREND.MNG firmware decoded the damageize handler (@0xf040f6f8) -- cmd 0x20
(vr_damage_action) writes the dpl_Punchize token triple onto the punch
geogroup's first three geometry chunks IN FILE ORDER:
chunk1 = the detailed window-aperture shapes -> an invisible per-pixel MASK
chunk2 = the coarse hull -> the ONLY colour-drawn geometry (where not masked)
chunk3 = byte-identical hull twin -> the damage-reset record, never visible
Visible canopy = hull-minus-apertures. Both earlier readings were wrong ways
around the same three chunks: dropping all punch left floating fragments (no
hull); hiding the duplicate pair hid the HULL and drew the MASK -- the exact
inversion observed.
Port: bgfload tags per punch patch {non-paired pmesh = mask (role 1),
first twin = hull (role 2), second twin = skip}; L4D3D DrawMesh runs
mask->stencil-1 (no colour/z-write, z-tested), hull->stencil-NOTEQUAL,
mask->stencil-0; device D24X8 -> D24S8 + stencil clear. The cut never
touches z, so later-drawn entities show through the apertures.
BT_COP_PLATES=1 disables (diag).
In-game, all 8 mechs on pure defaults: connected dark frames with clear
viewports -- thor (the footage mech) shows the central viewport + surrounding
frame exactly as filmed. Combat regression clean (kill + no NaN).
Arena textured punch uses the same firmware kit; the black-texel alpha path
there is a working approximation, flagged in the KB.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>