[Mesh Sampling] Vertex Color change while Downsampling of a Mesh File to PCD

Describe the bug

While Downsampling of a Mesh file (.ply) with specific colors into a Point Cloud file using pcl_mesh_sampling.exe using -write_color flag, the color of the points changes in the output file.

Context

Trying to downsample the mesh to a specific number of points by retaining the RGB color values.

Expected behavior

While downsampling the mesh, the points should be colored depending on the nearest (one-ring) vertices in the mesh,

Current Behavior

The points are given color which are not present in the mesh file.

Your Environment (please complete the following information):

• OS: Windows 10
• PCL Version [e.g. 1.11.1]

Possible Solution

As mentioned, nearest neighbours should be used while deciding the color of the points in the downsampled file

Additional context

Let me know if any other info is required.

Start by reproducing the issue with pcl_mesh_sampling.exe, the -write_color flag, a colored PLY mesh, and the generated PCD file. Compare output colors with the mesh's vertex colors and investigate how colors are selected during downsampling. Done means output points use colors from the nearest one-ring mesh vertices rather than colors absent from the input.