[brianmk]

Picks up brianmk/coin e1ef24baf (in brianmk/coin#84): Vulkan: restamp annotation overlay commands on a camera-only replay.

The bug

Gui::So3DAnnotation — the node behind every PartDesign preview, datum label, placement indicator and transform draggger — records its subtree inline and then marks those commands SO_RENDERPASS_OVERLAY, while they stay in the retained main list. On a camera-only frame that list is replayed and the frame view is restamped into each command, but the restamp loop skipped every OVERLAY-pass command, on the assumption that overlay commands are the ones re-recorded each frame. The promoted annotation commands are not re-recorded, so they kept the previous camera's view matrix.

That matters because the backend does consume the per-command view matrix for overlay commands: SoVulkanRenderBackendWideLine.cpp expands an overlay command's wide lines on the CPU with command.viewMatrix (deliberately, so the NaviCube keeps its own camera — see the "edges/axes drift" comment there). A PartDesign preview's outline is a wide line set, so after a camera move its segments were expanded against the old camera and the preview was drawn where that camera had put it — the reported "draft preview isn't shown correctly, and doesn't update when moving the camera". Frames captured with the new presented-frame hook show exactly that (magenta preview geometry left behind at the previous pose).

Fix

Restamp by position instead of by pass: commands before mainCommandCount belong to the last main traversal (promoted annotations included) and get the current view whenever they still carry the previous one; the overlay/decoration commands appended after that region were recorded this frame and already have it. Sub-camera commands keep their own view. Measured with COIN_VULKAN_BACKEND_DEBUG=1 while a preview is open and the camera moves:

before: retained=17 retainedOverlay=8 staleOverlayBefore=8 staleOverlayAfter=8 restamped=9
after:  retained=17 retainedOverlay=8 staleOverlayBefore=8 staleOverlayAfter=0 restamped=17

retainedOverlay=8 are exactly the annotation-promoted preview commands; before the fix all 8 kept the old camera, after it none does.

Same failure mode in other tools (all go through So3DAnnotation)

• PartDesign previews via PartGui::SoPreviewShape: Pad/Pocket (ViewProvider), Draft / Fillet / Chamfer / Thickness (ViewProviderDressUp), Pattern / Mirrored / MultiTransform (ViewProviderTransformed), Boolean, sketch-based features;
• transform draggers / gizmos: Gizmo, SoTransformDragger, TaskTransform, ViewProviderDragger;
• annotations/labels: ViewProviderDatum, SoDatumLabel, SoFCPlacementIndicatorKit, the viewer's own annotation.

Regression test

FreeCAD-DevTools fcprobe/vk_annotation_restamp_probe.py + .check.py (run with COIN_VULKAN_BACKEND_DEBUG=1): opens a Draft and a Fillet preview, moves the camera, and requires both that annotations were present (retainedOverlay > 0, so the check cannot pass vacuously) and that none was left stale (staleOverlayAfter == 0). It FAILS against the unfixed coin output (staleOverlayAfter=8) and passes with this bump.

Notes

• Presented-frame capture for the harness itself is in Gui/Vulkan: capture presented frames for the fcprobe harness #154 (debug-only), which is how the preview frames above were obtained.
• The stacked sketcher/viewport PRs that are still open predate this bump, so their submodule line should be taken from here when they land.

[brianmk]

Superseded by #155: this PR's substance (coin -> 738926470, the annotation-overlay restamp) is already the coin pointer in chore/vulkan-audit-fixes; the child's coin commit 9dd901061 is an ancestor of 738926470 in brianmk/coin. Closing to keep one PR per concern - the branch can be deleted.