The first-person cockpit now shows by default and matches gameplay footage
(verified on the Madcat). Two decomp-verified reconstructions:
EYEPOINT (FUN_004579a8 + caller part_014.c:5525, FUN_004c22c4):
- eye offset = siteeyepoint GetBaseOffset (not GetSegmentToEntity, not the
upright hack), parented on the PARENT segment DCS (btl4vid.cpp)
- live view = affine INVERSE of the eye world matrix (L4VIDRND Execute) --
replaces the hand-rolled LookAtRH whose +Z-forward/+Y-up row guess aimed
some mechs into the canopy; combine order fixed to baseOffset * R
- chase camera basis + aim boresight re-expressed for the inverse convention
(row2 = back); boresight now derives from the view matrix (the stale rows
aimed the pick ray at the sky = no target, no discharge)
CANOPY (*_COP.BGF, dpl_Punchize geogroups):
- every shell is an open strut lattice (38-59% boundary edges, all 12 mechs);
rendered single-sided with per-face INWARD winding (l/r torso patches are
mirrored, so no global winding works) the struts are the dark frame and the
openings show the world
- frame colour = the 'softer' ramp near its dark end (texture-less unlit ramp;
BLXSKIN.BMF has no texture -- the old "punch texels" theory was wrong)
- scoped by filename (meshIsCop); wrong drop-punch + view-cut paths removed
- BT_FORCE_MODEL=<name> forces the player mech for per-mech bring-up
KB: new context/cockpit-view.md topic; punch split corrected in bgf-format;
gotchas 14 (LookAt axis guess) + 15 (per-patch edge namespaces); env gates +
eye/punch addresses in decomp-reference.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The death/respawn "blue whirlwind" (tsphere) now matches the original cabinet
photo (capture.png): a smooth spinning lavender vortex with a bright core.
Root cause of the long-standing "radial spokes" artifact was NOT the warp code
but a general engine bug: L4D3D::SetTextureScrolling computed its texture-matrix
offset as scrollDelta * absolute_time, which grows unbounded and collapses UV
float precision -> a smooth scrolled cloud shatters into grainy radial steps.
Wrapped with fmodf(..., 1.0f) (identical under REPEAT tiling, full precision).
This also cleans the scrolling bexp beam grit and any other SCROLL material.
Visual reconstruction (verified against the real 45-vtx TSPHERE.BGF bicone,
offline-rasterized then ported):
- view ON-AXIS (eye centred on the throat) + spin in place -> concentric rings
(decomp FUN_00453dc4 does spin-about-local-Z + submit; the port had stubbed it)
- bintA cloud through a WIDE lavender ramp at full contrast (drawn as SKY);
no geometry "bands", no log-polar twist, no off-axis tornado (all discarded)
- tessellate the 12-facet bicone smooth; isotropic + trilinear; ramp baked into
the texture and drawn SELECTARG1(TEXTURE) to avoid double-tinting
Env knobs (BT_WARP_*) default to the verified values; BT_WARP_SELFTEST/SELFSHOT
are an off-by-default visual-verification harness (backbuffer frame dump).
Docs: new context/translocation-warp.md (geometry/material/visual/lifecycle/env);
reconstruction-gotchas.md gains the accumulated-time precision-collapse bug class;
rendering.md / multiplayer.md / decomp-reference.md / CLAUDE.md cross-linked.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Deep-dived the authentic engine effect (L4VIDRND.cpp POVTranslocateRenderable, T0)
and reworked our one-shot to match it, fixing the user's "blob from my own POV /
not aligned to my orientation" + "gray, not blue" reports:
1. PLACEMENT was the misalignment. The engine parents the sphere to the VTV/eye
("rotated and scaled around the VTV", L4VIDRND.cpp:1812) -- it is centered on and
oriented to the viewpoint. We world-fixed it at the mech's feet, so from your own
camera it sat off-axis and, once expanded, engulfed the eye as a shapeless blob.
Now: the own-respawn warp (BTStartWarpEffectPOV, from btplayer) uses
world = Scale(s) * inverse(view) -> centered on + carried by your eye (the tunnel
wraps you). Observing a PEER (BTStartWarpEffect from mechdmg) stays world-anchored
at the peer's point.
2. GEOMETRY SPIN was inauthentic. myRotateY/myRotateYSpeed are set in the engine
ctor but NEVER applied -- the swirl's rotation is entirely the material's texture
SCROLL (bintA, SCROLL 0.0 0.0 0.1 0.5). Dropped our world-Y geometry spin.
3. COLOR (gray) fixed at the source. The blue/white is the "sky" RAMP remapping the
grayscale bintA cloud per-texel (argb=lerp(0,0,0.6 -> .99,.99,.99, luminance),
L4D3D.cpp:480). The port bakes exactly this but GATED it off for normal-bearing
meshes; tsphere has normals so it arrived raw gray, and a MODULATE tint can't add
the blue floor (it only multiplies) -> the wash-out. Un-gate the ramp for
tsphere_mtl (bgfload.cpp) so the bound texture is already the blue-white swirl;
draw it MODULATE by white (no tint), alpha from TFACTOR.
4. SCALE to authentic 100 (collapse) / 150 (expand end) -- correct now that it's
eye-centered (you're meant to be inside it as it collapses through you and blasts
back open, the "blast off into the distance").
Still deferred (higher risk / SimulationState-coupling trap): the WaitForReincarnate
Lissajous wobble + the SetIsDead world-mask (black-out during the dead hold). Noted
for follow-up; the placement/color/motion are the parts the user flagged.
Smoke-verified 2-node: own respawn logs POV(eye), observer logs world-anchored, no
crash. BT_WARP_ADDITIVE / BT_WARP_COLOR / BT_WARP_SCALE remain as live tuning knobs.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Clean, self-contained extraction of the BattleTech-specific work from the
reverse-engineering workspace -- engine + game + content + build, with nothing
from Red Planet or the raw archive dumps. Builds green (Win32) and runs the
single-player drive->animate->target->fire->damage->destroy loop out of the box.
Layout:
engine/ MUNGA + MUNGA_L4 shared 2007 engine, carrying our BT render/loader
work (bgfload/L4D3D/L4VIDEO: BSL bit-slice decode, LOD/ground/shadow
models) + image codec; the minimal rp/ headers the audio HAL needs
game/ reconstructed BT logic + surviving-original BT source + fwd shims
+ WinMain launcher
content/ full runtime tree (BTL4.RES, VIDEO/, GAUGE/, AUDIO/, eggs, BTDPL.INI)
docs/ format specs + reconstruction ledgers
reference/ raw Ghidra pseudocode (recon source-of-truth) + decomp exporter
tools/ MP console emulator + map/resource scanners
One top-level CMake builds munga_engine lib + bt410_l4 game lib + btl4.exe.
All paths relativized (186 fwd shims + ~437 CMake abs paths -> repo-relative);
DXSDK is the one external, overridable via -DDXSDK. Verified: builds to a
byte-identical 2.27MB exe and runs combat (TARGET DESTROYED, 0 crashes) against
the bundled content.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
