Proposal: what 21 app integrations need from the shared host library (comfort budget in display info, texture hand-off per API, and a map of every per-app post)

[joehillthunder]

This post brings together what the 21 integrations below need from the planned shared host library, and links every per-app proposal. All of them follow the same pattern:

• the XR rig is pinned to the app's own camera;

• a true-geometry rig is fitted to the display;

• depth is held inside the comfort budget;

• the app's own UI and input stay its own.

Each one is classed as own viewport (texture mode) or dedicated 3D window, per the target-class comment on #2331. Leia SR is the tested display throughout.

1. The one runtime ask every adapter shares: the comfort budget in display info (#2388)

Panel size and nominal viewing distance already come from display info. But every adapter still hard-codes the front and behind disparity limits (0.14 % / 0.42 % of panel width on the tested display), so none of them carries over to another DisplayXR display. Publishing layout.comfort { front_frac, behind_frac } from the vendor plug-in turns each adapter's constant into a one-line swap.

Evidence that the strength has to be fitted to content against that budget, not a fixed constant: #2385 (a closed app needs 0.1 for its own content and 0.3 for imports), CLO (#2434: 100 % = budget, seated Pass, 125–150 % shows crosstalk), and Kit's frame-selection overshooting the behind budget (#2435).

2. What the host library needs to provide (merged from the per-app lists)

| Need | Asked by |

|---|---|

| Texture hand-off per graphics API. D3D11 exists (v9 texture target). Also needed: GL (WGL_NV_DX_interop2), Vulkan (VK_KHR_external_memory_win32; Houdini 22's viewport is Vulkan-only) and D3D12 sub-rect phase (#2382) | Slicer, ParaView, Blender, MotionBuilder, Nuke, Houdini, Omniverse, Maya |

| Self-pacing for texture sessions: xrWaitFrame doesn't pace them (#2386) | MotionBuilder, Nuke |

| A frame hand-off decoupled from the host's render rate: an eye pair plus the eyes it was rendered from (serial/ack). The shared dxrh_* core already does this and is a candidate seed | MotionBuilder, Nuke, Houdini, offline renderers (#2392) |

| External OpenXR apps, not only in-process adapters (VRED, Twinmotion, Substance Modeler), with per-process rig seeding from display info before xrCreateSession, and window placement (whole client, dock/undock, second monitor, F11) | VRED, Twinmotion, Modeler |

| App-framed rigs without the eye drift (#2422), and the eye near plane following the pull-back, so fly-throughs stay inside the budget | MotionBuilder, Maya, Nuke |

| A view-centred frustum option for renderers that drop off-axis frusta (Kit) | Omniverse |

| Focus as a glass shift at constant K, with the app passing its scene depth to the comfort clamp (#2385) | ParaView, Slicer |

| The adapter owns navigation: no runtime fly camera or emulated controllers for camera-pinned apps; per-app pad mapping; mouse-as-tracked-hand from the final views for closed VR apps | ParaView, Slicer, Modeler, Twinmotion, VRED |

| Live depth and focus as an API, relative to the app's nominal, replacing the window-property scaffolding (#2350) | all |

| "Place this content" / "frame this prim": a glass and push-back solve from bounds + camera + view rect | Stability (#2391), KitBash3D (#2435), materials (#2419) |

| Capture for measurement that works in texture mode (#2421), per instance (#2351), and with no viewer seated (#2384) | all measurement work |

| A rect publisher per UI toolkit (Qt widget → device-pixel rect), including a fractional-DPI rule | Slicer, ParaView, MotionBuilder |

3. The web route (DisplayXR Browser)

For apps with scripting and export but no draw hook (e.g. CLO, #2434), a page plus a plug-in works today. To make it a supported path:

• an opaque clear colour for display-rig eye cameras (displayxr-web#198);

• a fit-to-budget helper that follows zoom (displayxr-web#200);

• splat orbit style (displayxr-web#199);

• local page + live-folder access (displayxr-browser#203).

4. Per-app proposals

| App | Class | Post |

|---|---|---|

| NVIDIA Omniverse (USD Composer) | Own viewport (design); windowed today | #2331 |

| 3D Slicer | Own viewport (VTK texture hand-off) | #2352 |

| ParaView (+ Glance in the browser) | Own viewport (VTK texture hand-off) | #2360 |

| Blender | Own viewport (add-on) | #2397 |

| Autodesk Maya | Own viewport (texture target, running on v2.55.0) | #2390 |

| Autodesk MotionBuilder | Own viewer (texture target) | #2423 |

| Foundry Nuke | Own Viewer (texture target) | #2433 |

| SideFX Houdini | Dedicated 3D window (Vulkan hand-off needed for in-viewport) | #2432 |

| Autodesk VRED | Dedicated 3D window (external OpenXR app) | #2383 |

| Twinmotion | Dedicated 3D window (whole client) | #2389 |

| Adobe Substance 3D Modeler | Dedicated 3D window (closed legacy OpenXR app) | #2394 |

| Adobe Substance 3D Painter | Dedicated 3D window (Painter-rendered eyes); complete (2026-10-29) | #2437 |

| Adobe Substance 3D Sampler | Dedicated 3D window (live material) | #2438 |

| Adobe Substance 3D Designer | Own dock panel (texture target, own material view) | #2439 |

| CLO Virtual Fashion | Dedicated 3D window (DisplayXR Browser page) | #2434 |

| Sketchfab | Browser (WebXR today; inline-3D wall next) | #2441 |

| Off-the-shelf OpenXR apps (survey) | Hosted legacy / per app | #2440 |

| Offline / path-traced renderers | Dedicated 3D window (stereo pair player) | #2392 |

| NVIDIA Isaac Sim | Kit app: 3D Display XR mode via the Omniverse extension | #2463 |
| NVIDIA Instant-NGP | Own window (texture target, NeRF) | #2464 |
| SpAItial Echo-3 worlds | Content: streamed splats in the DisplayXR Browser | #2465 |
| Generated 3D content (image→3D) | Content in host views | #2391 |

| Measured materials (scanners) | Content in host views | #2419 |

| KitBash3D kits | Content in host views | #2435 |

5. Runtime issues filed from this work

#2384 · #2385 · #2386 · #2387 · #2388 · #2393 (fixed in v2.55.0) · #2395 · #2396 · #2421 · #2422 · #2430 · #2436 · draft PR #2429 (GL depth formats; unblocks Godot 4)

🤖 Generated with Claude Code

[dfattal]

Thanks @joehillthunder, this is the consolidated requirements list we needed. We'll use it as the input for the shared host library rather than answering each per-app post on its own.

Where things stand:

• The API draft is being reconciled against section 2. Your dxrh_* core, already shared by MotionBuilder, Nuke and Houdini, is a natural seed for the frame hand-off and the session lifecycle.
• The comfort budget in display info (Display info: publish the comfort budget (front/behind disparity limits), e.g. layout.comfort {front_frac, behind_frac} #2388) is on the list, as the one runtime ask every adapter shares.
• Runtime items:
  • Atlas capture: the post-compose trigger never fires on the D3D12 → D3D11 hub reroute (projection trigger works) #2387 is closed (fixed by P2c: the hub becomes THE implementation — one late-weave gate, one repaint thread, one presenter, one placement, one mask rasteriser; colour honesty at the import boundary; per-segment zone publish in the hub (#2317) #2342).
  • Atlas capture: the per-exe trigger writes nothing for texture-target (client-presents) sessions; window mode works #2421 has a fix in draft fix(compositor): texture-class sessions answer the post-compose atlas trigger (#2421) #2426.
  • xrWaitFrame doesn't pace a session that submits no layers (about 8,700 frames/s before the first image) #2386, XrCameraRigDXR: with an app-framed verticalFov wider than canvas-true, the eyes land far above the app camera and the frustum is entirely below the horizon #2422, D3D12: Khronos hello_xr loses its device on the first frame (DXGI_ERROR_INVALID_CALL) #2430 and In-process runtime: leia-sr plug-in fails to load in some host processes (dependency not on the search path) and silently falls back to sim-display #2436 are in triage.
  • fix(gl): advertise depth swapchain formats on the native GL compositor #2429 is in review.

We'll post the host-library design here when it's ready, with each row of section 2 marked as covered, deferred or out of scope.

The most useful next step on your side is the panel: launch each repo you fixed for hygiene on the installed runtime, and run the pending seated checks (Maya, MotionBuilder residual, CLO comfort at the fitted strength). That turns the candidates into hosting-ready integrations.

[joehillthunder]

Status for the Desktop apps table on displayxr.org (2026-10-29)

Every row on https://displayxr.org/platform-support#desktop-apps now has a seated check on a released runtime posted on its proposal. Results are reported as Pass / Fail with conditions.

App	Table today	Seated check on a released runtime	Post
Blender	Seated-verified	Pass	#2397
NVIDIA Omniverse USD Composer	Seated-verified	Pass, v2.57.1 + Leia SR 2.19.1, readiness 6/6	#2331
Autodesk Maya	Seated-verified	Pass	#2390
Autodesk MotionBuilder	Seated-verified	Pass; readiness Pass v2.55.0	#2423
Foundry Nuke	Seated-verified	Pass; readiness Pass v2.55.0	#2433
3D Slicer	Seated-verified ✓	Pass, v2.55.0 + Leia SR 2.18.3, in its own 3D view	#2352
ParaView	Seated-verified ✓	Pass, v2.57.1 + Leia SR 2.19.1, in its own render view	#2360
Adobe Substance 3D Designer	Seated-verified ✓	Pass, v2.57.1 + Leia SR 2.19.1, in its own dock	#2439
SideFX Houdini	Proposed	Pass, v2.57.1 + Leia SR 2.19.1 (resolution/latency below target)	#2432
Autodesk VRED	Proposed	Pass, v2.57.1 + Leia SR 2.19.1 (dedicated window)	#2383
Twinmotion	Proposed	Pass, v2.53.1	#2389
Adobe Substance 3D Modeler	Proposed	Pass at 1.1× front budget; readiness Pass on the installed runtime, framing needs #2334 (dev runtime until it ships)	#2394
Adobe Substance 3D Painter	Seated-verified ✓	Pass; complete (Kit 110 USD/RTX Pass, #2436 closed)	#2437
Adobe Substance 3D Sampler	Seated-verified ✓	Pass, v2.57.1 + Leia SR 2.19.1	#2438
CLO	Seated-verified ✓	Pass at 100 %; readiness Pass v2.55.0	#2434

Thanks for #53 (Isaac Sim and Instant-NGP added; nine rows moved). Still to move: Houdini, VRED, Twinmotion and Modeler, each with a seated Pass on a released runtime above. SpAItial Echo-3 worlds (#2465) is content in the DisplayXR Browser with a seated Pass, if it belongs on the page.

@dfattal, two asks:

1. Could Houdini, VRED, Twinmotion and Modeler move to Seated-verified when you next update the table?
2. What does a row need to become Supported / shipped? For example: the host library release, signed packaging, a minimum runtime version, or a hosted install path. We'll work to that list.