Elevation profile DTM interpolation method may not be consistent with the projection of 2D point on terrain

[Simon-Lopez]

What is the bug or the crash?

Projection of 2D points on a terrain (Clamped to Terrain option) seems to use a nearest neighbor approach. As it is not the same as that used to draw the terrain profile in the Elevation Profile view (interpolation) we observe inconsistencies when zooming in the elevation profile view (cf. picture below).

Steps to reproduce the issue

1. Create a layer with points
2. Clamped them to terrain (Settings -> Elevation tab)
3. Observe the point on a elevation profile

Versions

3.40.0

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

No response