ElevationLayer: only apply the reverse vdatum transform for non-nodata

gwaldron · Dec 20, 2024 · 536e052 · 536e052
1 parent 1d2e910
commit 536e052
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/src/osgEarth/ElevationLayer.cpp b/src/osgEarth/ElevationLayer.cpp
@@ -345,10 +345,14 @@ ElevationLayer::assembleHeightField(const TileKey& key, ProgressCallback* progre
                         auto& source = sources[k].second;
                         if (source.getExtent().contains(points[i].x(), points[i].y())) // prevents clamping of out-of-bounds points
                         {
-                            h = sources[k].second.getElevation(points[i].x(), points[i].y(), INTERP_BILINEAR)
-                                - points[i].z(); // apply vdatum offset
+                            h = sources[k].second.getElevation(points[i].x(), points[i].y(), INTERP_BILINEAR);
                         }
                     }
+                    if (h != NO_DATA_VALUE)
+                    {
+                        // apply reverse vdatum offset if necessary
+                        h -= points[i].z();
+                    }
                 }
             }