fix: use globe terrain when framing an ALPR camera

CHANGELOG.md

@@ -3,7 +3,8 @@
 ## ALPR camera locations
 
 - Label the loaded camera count as nearby, show a purple-dot legend, and add
-  SHOW NEAREST to frame and select a loaded camera when none are on screen.
+  SHOW NEAREST to frame and select a loaded camera when none are on screen,
+  using the available 3D-tile or globe terrain height.
 
 - Keep nearby camera markers and selection stable during rotation, use bounded
   ground-centered coverage instead of the horizon rectangle, and reuse in-flight queries.

docs/CURRENT-STATE.md

@@ -13,7 +13,8 @@ The row count explicitly says **nearby**: loaded records can be outside the
 screen. A purple-dot legend identifies the fixed 8-pixel markers (12 pixels when
 selected). **SHOW NEAREST** frames and selects the nearest loaded camera; it is
 disabled with no loaded cameras or while following a tracked entity. This action
-chooses from the current source snapshot.
+chooses from the current source snapshot and uses rendered surface height from
+3D tiles or globe terrain when available.
 Coverage follows a bounded neighborhood around the screen-center ground point,
 with a radius of twice the camera-to-ground range (at least 1 km), rather than
 extending to the horizon. Sky, dateline-crossing and wider-than-city views do not

src/data/alprCameras.test.mjs

@@ -1093,6 +1093,8 @@ test('nearby count and discovery control frame a real loaded camera without fetc
   );
   h.viewer.camera.flyToBoundingSphere = (sphere, options) =>
     flights.push({ sphere, options });
+  h.viewer.scene.globe.show = true;
+  h.viewer.scene.globe.getHeight = () => 312;
   try {
     assert.equal(alprCamerasLayer.getRowControls().chips[0].disabled, true);
     await alprCamerasLayer.update();
@@ -1106,6 +1108,10 @@ test('nearby count and discovery control frame a real loaded camera without fetc
     assert.ok(
       Math.abs(Cesium.Math.toDegrees(center.latitude) - 30.2672) < 1e-9,
     );
+    assert.ok(
+      Math.abs(center.height - 312) < 1e-6,
+      'use the rendered globe floor on keyless basemaps',
+    );
     assert.equal(flights[0].options.offset.range, 800);
     assert.equal(h.requests.length, 1);
     h.viewer.trackedEntity = {};

src/layers/alpr/presentation.js

@@ -276,6 +276,8 @@ export function createAlprPresentation({ state, services, source }) {
         /* tiles may still be streaming */
       }
     }
+    if (!Number.isFinite(height) && state.viewer.scene.globe.show)
+      height = state.viewer.scene.globe.getHeight?.(location);
     if (!Number.isFinite(height) || height < -500 || height > 10000)
       height = cachedGroundFloor(record.latitude, record.longitude);
     const center = Cesium.Cartesian3.fromDegrees(