**Note** from Bead: Incident Viewer Epic 5 · [canonical source](https://redfish.acequia.io/guerin/.agents/84395793-e621-4739-81e4-fe247b9e6003/2026-06-25/notes/06-yellow-block-and-fmv-frustum.md) · session 2026-06-25 · discussion: Talk: Incident Viewer Epic 5
**2026-06-25 / 26.** Two follow-ups from Stephen testing live. Both live on BOTH hosts → `index-CNbbsoIc.js`.
## The "yellow block in the way on H" — root cause + fix The earlier declutter (note 05) hid the camera MARKER glyphs during look-through, but the yellow block persisted. The real culprit: the **amber platform marker** (`markerMat` `[1.0,0.72,0.25]`, the live aircraft glyph) and the AIR7 marker/track. The `AircraftTracks` and `Air7` features gated their declutter on `sensorLock || flyingTo` but **omitted `camLock`** — so during a CAMERA look-through the amber aircraft marker sat right at the eye and read as a yellow block. Fix: add `camLock` to both gates (`index.ts` ~2050 and ~2134). `feat/elevation-assertion` (yellow-block + FMV-frustum commits).
## FMV sensor frustum (Stephen: "i do want the frustum from the fmv camera, separate from the air track") The FMV's position prior rides the AIR7 ADS-B track, but the **sensor's own frustum** is separate — and the FMV drew none. Added an `FmvFrustum` feature: **4 corner rays from the sensor eye to the video-footprint corners**, computed as the 4 FOV corner rays (`s.hfov/s.vfov` from telemetry) intersected with the horizontal plane at the frame-center elevation (flat-ground approx; terrain raycast is a later refinement). - Toggled by the **same `F`** as the camera whiskers; hidden during the FMV's own sensor-lock (you'd be inside it) and when the image (`i`) is off. Rebuilt per frame (the sensor moves) with the prior mesh `destroy()`ed to avoid the per-tick GPU-buffer leak. - **CDP-verified** (FMV loads headless): with the FMV clip visible + its time-span set + frustum on, the cyan corner rays converge from the aircraft (alt ~3.2 km, hfov 38.8°/vfov 21.8°, slant ~5.6 km) onto the draped video footprint. [`tools/_e5-fmvfrust-final.png`].
## To confirm live (Stephen) - Camera look-through ('H') no longer shows the amber aircraft marker / AIR7 (the yellow block is gone). - Press **`F`** with the FMV clip visible → the FMV sensor frustum (cyan rays to the footprint corners). Judge whether the corner-landing needs the terrain-raycast refinement vs the flat-ground approx.
## Notes - The camera whiskers are on AlertWildfire/posed-still CamCards (Point cameras); the FMV frustum is the aircraft-sensor analog. Both share the `F` toggle and the cyan `whiskerMat`. - Default item visibility is OFF, and a clip must be in the visible time-window for its drape/frustum to show — both the FMV drape and the FMV frustum honor that gate.