PolyArcStereoND

UE 5.5.4 project for curved polarized LED stereoscopic display rendering, rebuilt on top of nDisplay (replaces the discontinued from-scratch PolyArcStereo plugin).

Why nDisplay

The custom multi-frustum rendering pipeline (4×2 SceneCaptureComponent2D + custom off-axis matrix + manual RHI compositing) we tried in the previous project hit too many UE5 internal coordinate-system conventions, view-space basis traps, and PostProcess re-enable footguns. nDisplay's Simple projection policy already implements exactly the same Kooima off-axis math, with all the basis sign conventions handled correctly and the multi-viewport rendering (Lumen/TAA history/shadow cascade) properly shared.

What we keep from the old project:

• Design doc §1.4 (project parameters: L=6720mm, R=12052.62mm, θ=31.948°, 3612×2236 px, etc.)
• Concept of M4 cross-talk compensation and M5 column-interleave output
• Stereo3D544 host project's ScreenGeometryAsset values (re-encoded as nDisplay config)

What we replace:

• M1 (geometry visualization) → UDisplayClusterScreenComponent placed in level
• M2 (multi-frustum stereo rig) → nDisplay viewports with Simple projection policy
• M3 (sub-RT → canvas compositing) → nDisplay built-in frame composition

What stays our IP (custom PolyArcStereoFX plugin under Plugins/):

• M4 Cross-Talk Compensation → IDisplayClusterPostProcess::PerformPostProcessViewAfterWarpBlend_RenderThread
• M5 Column-Interleave Output → IDisplayClusterPostProcess::PerformPostProcessFrameAfterWarpBlend_RenderThread

Repo structure

PolyArcStereoND/
├── PolyArcStereoND.uproject
├── Source/                           Project module
│   ├── PolyArcStereoND/             (Runtime module, currently empty - room for level scripts)
│   ├── PolyArcStereoND.Target.cs
│   └── PolyArcStereoNDEditor.Target.cs
├── Plugins/
│   └── PolyArcStereoFX/             Our custom nDisplay extension (M4 + M5)
│       ├── PolyArcStereoFX.uplugin
│       └── Source/PolyArcStereoFX/
│           ├── PolyArcStereoFX.Build.cs
│           ├── Public/PolyArcStereoFXModule.h
│           └── Private/PolyArcStereoFXModule.cpp    (factory registration scaffold)
├── Config/
└── Content/                          Future: nDisplayConfig asset, DisplayClusterRootActor blueprint

Build

UE 5.5.4 + Visual Studio 2022. Right-click PolyArcStereoND.uproject → "Generate Visual Studio project files" → build the editor target.

& 'D:\Program Files\Epic Games\UE_5.5\Engine\Build\BatchFiles\Build.bat' `
  PolyArcStereoNDEditor Win64 Development `
  'D:\Claude\UE5\PolyArcStereoND\PolyArcStereoND.uproject' `
  -WaitMutex -FromMsBuild -MaxParallelActions=2

-MaxParallelActions=2 needed on this machine due to pagefile constraints.

Plugins enabled

• nDisplay (Engine/Plugins/Runtime/nDisplay) — production-ready, IsBetaVersion: false in 5.5.4
  • Includes sub-modules: DisplayCluster, DisplayClusterConfiguration, DisplayClusterProjection, DisplayClusterShaders
• PolyArcStereoFX (this project's custom plugin)
• ModelingToolsEditorMode (template default, kept)

Next steps (in this project)

1. Build & launch editor (verify nDisplay enabled, no compile errors)
2. Add a DisplayClusterRootActor to a test level
3. Author nDisplay config asset: 4 viewports × 2 eyes, each viewport with Simple projection policy pointing at a DisplayClusterScreenComponent placed per arc geometry
4. Verify off-axis projection in editor preview (HasPreviewMesh=true so Simple policy supports it)
5. Implement M4 cross-talk PostProcess (2×2 matrix compute shader operating on each viewport's post-warp output)
6. Implement M5 column-interleave PostProcess (compute shader picking odd/even columns from L/R eye RT into final canvas)

Related repos

• (archived) old multi-frustum attempt: https://github.com/smallPotatoBoy/PolyArcStereo + https://github.com/smallPotatoBoy/Stereo3D544
• Design doc on Feishu: https://www.feishu.cn/docx/Kijydtwm8oGAPxxNfOicCnKengd
• Handoff notes on Feishu: https://eolm6fi2sn.feishu.cn/docx/HgKjdj3I4oCgOfxutfVcGwE4n2r