Filter LAS

Category: Mega-Polis → Generation → Generation Design Tools
Node ID: SvMegapolisFilterLas
Tooltip: Filter Las
Dependencies: laspy, numpy

Functionality

Filters a LAS point cloud by classification and outputs:

  • the filtered LAS point record (subset of points)
  • the corresponding XYZ coordinates as Sverchok vertices

The node reads the LAS file header (scales + offsets) from the Path input, then uses the incoming Points Data (LAS point record / point cloud data) to select only points whose classification matches the chosen class. Coordinates are computed as:

  • X = points_filtered.X * scale_x + offset_x
  • Y = points_filtered.Y * scale_y + offset_y
  • Z = points_filtered.Z * scale_z + offset_z

Inputs

Socket Type Description
Path SvFilePathSocket Path to the .las file (used to read header scales/offsets). Must be linked.
Points Data SvStringsSocket LAS point data object (expects attributes like .points and .classification). Must be linked.

Parameters

Name Type Default Description
classification Enum ground Select which LAS classification to filter.

Available classifications

  • never
  • uncla
  • ground
  • low_vegetation
  • med_vegetation
  • high_vegetation
  • building
  • noise
  • reserved
  • water
  • rail
  • road
  • overlap
  • wire_guard
  • wire_conductor
  • transmission
  • wire_connector
  • bridge
  • high_noise

Outputs

Socket Type Description
Points Data Filtered SvStringsSocket Filtered point record subset (points_filtered).
Points SvVerticesSocket Filtered point coordinates as [[x, y, z], ...] wrapped as [coordinates].

Example

Filter only “ground” points

  1. Use Read LAS to load a LAS file and output Points Data (point record data).
  2. Connect:
    • Read LAS → Points Data → Points Data
    • The same LAS file path → Path
  3. Set classification to ground.
  4. Use:
    • Points to visualise or mesh only ground points
    • Points Data Filtered for downstream attribute workflows