Modern open-source C# .NET 10 Asheron's Call client. Faithful port of retail client behaviour to Silk.NET with a plugin API.
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Erik 0940d7961a fix(render): Phase A8 — cell-mesh Landblock CullMode → None + cull state restore
The cull A/B diagnostic (prior commit's ACDREAM_A8_DISABLE_CULL=1) in
visual-gate-#3 confirmed: cell-mesh polys are being culled by back-face
culling, which is why floors disappear when looking down from inside a
room. Per-cell audit data showed every cell-mesh batch has
CullMode.Landblock — assigned because AC's CellStruct polys carry
SidesType=Landblock in the dat. Our SetCullMode maps Landblock to
glCullFace(Back), matching WB.

Root cause:
WB sets `glFrontFace(GLEnum.CW)` globally at GameScene.cs:843. Our
WbDrawDispatcher.cs:1056 sets `glFrontFace(CCW)` — the GL default,
opposite of WB. With our flipped-from-natural fan triangulation in
BuildCellStructPolygonIndices (which emits (i, i-1, 0) for each fan
triangle, reversing the input vertex order), the resulting effective
winding from the camera's perspective is OPPOSITE WB's. Cull-back then
removes the OPPOSITE face from what WB does — hiding the floor side
that should be visible from inside the room.

Within a single cell-mesh batch, the polys face every direction (walls
outward, floor up, ceiling down) but all share CullMode.Landblock. No
single cull setting can be correct for all three orientations
simultaneously — the retail-faithful approach is to render cell polys
double-sided (cull off).

Two changes scoped to EnvCellRenderer.RenderModernMDIInternal so other
renderers aren't affected:
  1. Remap CullMode.Landblock → None when iterating per-cull-mode
     batch groups. Cell polys render with cull disabled, all faces
     visible. CullMode.Landblock is only assigned by
     PrepareCellStructMeshData (cell polys) in this codebase — terrain
     uses a different render path. Scope is exactly right.
  2. Explicitly Enable(CullFace) + CullFace(Back) at Render exit so the
     dispatcher's subsequent IndoorPass + LiveDynamic Draws don't
     inherit the cull-disabled state. The see-through-head symptom in
     visual-gate-#3 was caused by exactly this state leak from the
     ACDREAM_A8_DISABLE_CULL=1 diagnostic; the proper fix needs the
     explicit restore. Also updates the static `_currentCullMode` cache
     so the next Render call's first SetCullMode comparison is correct.

Removed the ACDREAM_A8_DISABLE_CULL diagnostic env var — its role as
A/B test is complete. 14/14 EnvCellRenderer tests pass. Build green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-27 20:12:20 +02:00
docs fix(render): Phase A8 — pool aliasing in EnvCellRenderer (visual chaos root cause) 2026-05-27 19:08:49 +02:00
memory fix(physics): L.4 — steep airborne hits slide-tangent (interim, deviates from retail) 2026-04-30 13:22:07 +02:00
references chore(submodule): advance WB to acdream-fix-floor-rendering 2026-05-19 13:23:19 +02:00
src fix(render): Phase A8 — cell-mesh Landblock CullMode → None + cull state restore 2026-05-27 20:12:20 +02:00
tests fix(render): Phase A8 — pool aliasing in EnvCellRenderer (visual chaos root cause) 2026-05-27 19:08:49 +02:00
tools test(phys): A6.P5 fixture — 3 ticks from live door-stuck capture 2026-05-25 12:43:51 +02:00
.gitignore test(phys): A6.P5 fixture — 3 ticks from live door-stuck capture 2026-05-25 12:43:51 +02:00
.gitmodules phase(N.0): wire up WorldBuilder fork as submodule + project refs 2026-05-08 08:51:49 +02:00
AcDream.slnx refactor(app): extract typed RuntimeOptions for startup env vars (Step 1) 2026-05-17 09:16:55 +02:00
CLAUDE.md docs: #100 ship + indoor-cell culling investigation handoff 2026-05-25 22:17:51 +02:00
launch-a6-issue98-capture.ps1 docs(research): A6.P3 #98 — comparison harness findings + neighborhood fixtures 2026-05-23 20:12:43 +02:00
launch-a6-issue98-cottage-gfxobj-dump.ps1 test(phys): A6.P3 #98 — comparison harness reproduces cottage-floor cap 2026-05-23 20:44:50 +02:00
launch-a6-issue98-polydump.ps1 docs(research): A6.P3 #98 — comparison harness findings + neighborhood fixtures 2026-05-23 20:12:43 +02:00
NOTICE.md chore(O-T1): create Core/Rendering/Wb directory + NOTICE.md attribution 2026-05-21 14:59:56 +02:00
README.md docs: add docs/ISSUES.md tactical issue tracker + CLAUDE.md rules 2026-04-25 00:08:15 +02:00

acdream

A modern open-source C# / .NET 10 Asheron's Call client.

Faithful port of the retail client's behaviour to Silk.NET with a modern, plugin-friendly architecture. The code is modern; the behaviour is retail.

Status: playable pre-alpha. You can log in to an ACE server, walk and run through Dereth, see other players animate correctly, watch the day-night cycle, hear ambient audio, and take weapons out. Many systems are still stubbed or in-progress — see roadmap.

Stack

  • Language: C# .NET 10
  • Graphics: Silk.NET (OpenGL 4.3)
  • Audio: OpenAL via Silk.NET
  • Dat parsing: Chorizite.DatReaderWriter
  • Networking: Custom UDP + ISAAC cipher + game-message layer, wire-compatible with ACEmulator server

What works

  • Connecting to a local ACEmulator (ACE) server on 127.0.0.1:9000
  • Character selection and login
  • Rendering Dereth terrain with retail-correct texture blending, per-vertex lighting, and road overlays
  • Static scenery (buildings, trees, scenery objects) via EnvCell walker
  • Animated characters (own + remote) with walk / run / strafe / jump / turn / attack motions sourced from the retail motion tables
  • Network sync with remote players — you can watch other characters animate correctly, including speeds and directional motion
  • Day-night cycle driven from the retail Region dat (0x13000000) — correct DayGroup picking via the retail LCG, correct keyframe interpolation, correct per-keyframe sky-object replace
  • Weather (rain/snow particles synced from the server via the retail DayGroup name)
  • Sky dome, stars, moon, clouds, sun — each rendered from the retail Region's SkyObjects with texture scrolling and alpha fade
  • Plugin host with live event replay-on-subscribe

What's stubbed or in-progress

  • Indoor transitions (building interiors) — disabled, Phase B.3 pending
  • Combat — animation works, damage math not wired
  • Lightning visual — the retail PhysicsScript-driven flash is researched but not wired (see docs/research/2026-04-23-lightning-real.md)
  • TimeSync drift — we only sync calendar on login, not periodically, so acdream's in-game clock gradually drifts from retail's
  • Landscape draw distance — currently ACDREAM_STREAM_RADIUS=2 (~400m) vs retail's several kilometres

See docs/plans/2026-04-11-roadmap.md for the ordered phase list. See docs/ISSUES.md for the rolling list of known bugs + small deferred features (tactical, bug-level; the roadmap is strategic, phase-level).

Building + running

Requires:

  • .NET 10 SDK
  • A retail Asheron's Call dat directory (Turbine/Microsoft property — supply your own). Contains client_portal.dat, client_cell_1.dat, client_highres.dat, client_local_English.dat.
  • A running ACE (ACEmulator) server on 127.0.0.1:9000 (or override via env var)

Launch (PowerShell on Windows — bash has trouble with the apostrophe in "Asheron's Call"):

$env:ACDREAM_DAT_DIR   = "$env:USERPROFILE\Documents\Asheron's Call"
$env:ACDREAM_LIVE      = "1"
$env:ACDREAM_TEST_HOST = "127.0.0.1"
$env:ACDREAM_TEST_PORT = "9000"
$env:ACDREAM_TEST_USER = "testaccount"
$env:ACDREAM_TEST_PASS = "testpassword"
dotnet run --project src\AcDream.App\AcDream.App.csproj -c Debug

Offline CLI dat inspector (no server needed):

dotnet run --project src/AcDream.Cli -- "C:\path\to\Asheron's Call"

Diagnostic env vars

Variable Effect
ACDREAM_DUMP_SKY=1 Per-second dump of the interpolated SkyKeyframe values + per-SkyObject draw info + texture alpha histograms
ACDREAM_DUMP_MOTION=1 Dump every inbound UpdateMotion + resulting SetCycle
ACDREAM_STREAM_RADIUS=N Tune landblock visible-window radius (default 2 = 5×5)
ACDREAM_NO_AUDIO=1 Suppress OpenAL init
ACDREAM_DAY_GROUP=N Force a specific DayGroup index for A/B-testing weather presets
ACDREAM_RUN_SKILL=N / ACDREAM_JUMP_SKILL=N Client-side run/jump skill (default 200)

Layout

src/
  AcDream.App/                   rendering + audio + main loop (Silk.NET)
  AcDream.Core/                  game state, meshing, physics, sky, weather, lighting
  AcDream.Core.Net/              UDP + ISAAC + game-message layer
  AcDream.Cli/                   offline dat-inspector console app
  AcDream.Plugin.Abstractions/   plugin host interfaces
  AcDream.Plugins.Smoke/         example plugin

tests/
  AcDream.Core.Tests/            xUnit tests (742 passing)
  AcDream.Core.Net.Tests/        network-layer tests

tools/
  RetailTimeProbe/               Win32 P/Invoke ReadProcessMemory probe of
                                 the live retail acclient.exe — dumps
                                 TimeOfDay + sky-lighting globals so we
                                 can compare against acdream's state
  SkyObjectInspect/              dat-inspector for Region sky objects

references/                      vendored read-only reference code — ACE,
                                 ACViewer, WorldBuilder, holtburger,
                                 AC2D, Chorizite, DatReaderWriter.
                                 Gitignored.

docs/
  architecture/                  single-source-of-truth architecture doc
  plans/                         phase roadmaps + per-phase specs
  research/                      decompile-derived research, per-phase
                                 findings, deep-dive agent reports
  audit/                         phase-completion audits

Development workflow

All AC-specific behaviour is ported from the decompiled retail client (docs/research/decompiled/). The workflow is:

  1. Decompile first. Find the matching function in the decompiled client.
  2. Cross-reference. Check against ACE's C# port and ACViewer / WorldBuilder.
  3. Write pseudocode. Translate C to readable pseudocode first.
  4. Port faithfully. Translate line-by-line, preserving variable names and control flow.
  5. Conformance test. Add tests using golden values from retail.
  6. Integrate surgically. Minimise churn in the surrounding pipeline.

Guessing at AC-specific algorithms is explicitly forbidden — see CLAUDE.md for the full workflow rationale and the list of failure modes we've paid for in the past.

Reference repos

We cross-reference five external projects for every retail behaviour:

  • ACE (ACEmulator) — authoritative server-side protocol
  • ACViewer — MonoGame dat viewer; good for character appearance
  • WorldBuilder — Silk.NET dat editor; matches our stack
  • Chorizite.ACProtocol — clean-room C# protocol library
  • holtburger — most complete non-retail client; Rust TUI, full client-side behaviour
  • AC2D — C++ AC-client emulator; has the real terrain split formula and 0xF61C movement packet format

See CLAUDE.md for which reference is authoritative for which domain.

Licence

Not yet chosen. All external reference code is vendored under its own licence; see references/*/LICENSE. The acdream source code itself is unreleased — not yet distributed to the public. Once the licence choice is made it will go in a top-level LICENSE file.

The AC dat files and the game's intellectual property remain the property of Microsoft / Turbine. This project does not distribute any of those files or assets — you must supply your own retail install.