PointCloudSurfaceBuilder Fails to Generate Usable Surface

I'm attempting to use PointCloudSurfaceBuilder in FME 2024 to build surfaces from a classified LAS point cloud (3D, ~3.6 million points, CSRS.UTM-11N), as part of a workflow to generate pit-free canopy height model (CHM) slices.

My goal is to use the Search Radius parameter to control triangle edge length and prevent long connections across canopy gaps. However, I’m consistently running into the following issues:

• Surface output is sparse or almost empty, even when using the full unfiltered point cloud (no slicing or thinning).

• Changing Search Radius from 0.45 to 1.5 to 10 meters does not resolve the issue — only a few tiny triangles are ever generated.

  

• Processing time exceeds 30 minutes per tile.

• SurfaceModeller OR RasterDEMGenerator works quickly and gives a full raster, but lacks control over triangle size (i.e., cannot limit interpolation distance).

• Repeated warnings appear in the log:

  

My questions are:

• Why does the surface fail to build even with a large Search Radius and full input?

• Is there a more reliable alternative for controlling triangulation size while producing raster output?

Any insight or guidance would be appreciated!

Thanks!