Entry 61

Mac Anu fixed up: the near plane cut as VU1 cuts it, blades in Kite's hands, the town's lights, and the Chaos Gate

2026-09-23worldrendertest

Filescrates/piney-gs/src/convert.rscrates/piney-world/src/camera.rscrates/piney-world/src/chara.rscrates/piney-world/src/town.rscrates/piney-world/src/gate.rscrates/piney-data/src/libm.rstools/test_world_rs.py

After 59 the user walked around Mac Anu and reported three problems:

• the camera clipped through floors;
• the weapons were not in Kite's hands;
• props were missing, "like the save build room".

The world agent traced each one to the game's code. Its two helpers took the weapons and the props.

The camera: a drawing bug, not a camera bug

• The camera matched. In a town, camera.cpp's floor handling already matched the game. cameraPosCalc (0x00161870) pulls the camera to 10 units short of the first bit-2 polygon on the line from Kite's head, and every one of Mac Anu's 828 hit polygons has bit 2.
• The drawing did not. VU1's mc_DrawTriSFast cuts an unlit triangle that is not wholly in view, when its last strip vertex has w below divZ (1000), at the near plane w = 8 (mc_ScissorTriPolyXYZ). The port dropped such triangles whole, so the floors and walls the camera was pulled against lost their nearest triangles.
• The fix. piney-gs now cuts them the same way, interpolating UV and colour, for models that do not ask to be rejected whole. The town's unlit pieces take that path.
• Fields too. avoidObstacle (0x00162430), which keeps the camera 50 above a field's ground, is ported for later. It needed newlib's tanf and fmodf, added bit-exact to piney-data::libm.

The blades

• What the game does. ccPlayer::ccPlayer (gcmn 0x00597910) finds the hands with ccClump::GetObjAdrsF, which searches only the clump's own nodes. ccSpcChar::EquipWeapon (0x0059d650) then sets each blade model on its hand node with no offset.
• The bug. The body file also holds an unposed copy of each hand name per animation. The port's name lookup found that copy first, whose matrix falls back to the root: the blade at his feet.
• The fix. The port now looks among the clump's nodes, as the game does.

The props

• The town draw. ROOTTOWN01::Draw run in eemu, over 953 camera eyes in town01 and 713 in town01d, selects exactly what the port selects. The branch that looked wrong is the game's own dead code.
• Two real bugs fixed on the way:
  • the five omni lights were misread (intensity 600, a garbage fall-off); they are intensity 1, fading from 600 to 800, so Kite is now shaded as the game shades him;
  • the crisis town's sky overlays were not drawn.
• The missing prop: the Chaos Gate. It is drawn by the entry control, not by the town (ccSetChaosGate gcmn 0x00458df0, ccChgate):
  • its ring (CMP_xmgtwav0, ANM_xmgtcir1, a 91-frame loop) at the gate dummy, within 4,500 of Kite;
  • its magic-circle state machine with sounds 71 and 72;
  • its light added to the town's.
• "The save build room". This is the Recorder's booth, which is town geometry and was already drawn. The Recorder standing in it is one of the five merchants, which come with the NPCs.

Checked

• Against the game's code. tools/test_world_rs.py, 12 tests, 0 mismatches:

  • test_avoid_obstacle: 1,500 cases;
  • test_frames_floors: the camera pressed into six stairs and slopes, 480 frames each, frame by frame;
  • test_weapon: 200 frames. The game's EquipWeapon, ccObj::Draw and _SetLWMatrix agree to 1.5e-5 per rotation element and 0.0034 in position.
  • test_town_draw: the draw selection over the camera eyes above;
  • test_gate: 800 frames of ccChgate;
  • the earlier tests, and tanf and fmodf added to the math checks.

  I re-ran the weapon, gate, town-draw and obstacle tests in a clean worktree (253 s); they pass.

• The rest. The workspace's tests pass, and clippy and fmt are clean.

• Shots. Kite on the bridge stairs, both blades in his hands and the steps drawn to the bottom of the screen. A wall beside the camera that was a hole is now drawn.