Convert OBJ to LAS

Understanding OBJ and LAS file formats

OBJ is a widely used 3D geometry definition file format developed by Wavefront Technologies. It stores 3D models as a collection of vertices, faces, normals, and texture coordinates, making it popular for 3D modeling and printing applications.

LAS is a public file format for the interchange of 3D point cloud data, commonly used in LiDAR (Light Detection and Ranging) applications. It efficiently stores large sets of points with attributes like position, intensity, and classification.

Why convert OBJ to LAS?

Converting OBJ to LAS is essential when you need to use 3D mesh data in point cloud processing workflows, such as GIS, surveying, or LiDAR analysis. LAS files are optimized for handling large point clouds and are compatible with many geospatial tools.

How to convert OBJ to LAS

Since OBJ files store mesh data and LAS files store point clouds, the conversion process involves sampling points from the OBJ mesh. Here’s how you can do it:

Using CloudCompare (recommended software)

1. Download and install CloudCompare from the official website.
2. Open CloudCompare and go to File → Open to import your OBJ file.
3. Select the imported mesh in the DB Tree.
4. Convert the mesh to a point cloud by selecting Tools → Mesh → Sample points.
5. Adjust the sampling parameters as needed and click OK.
6. With the new point cloud selected, go to File → Save and choose LAS as the output format.

Alternative tools

• MeshLab: Import the OBJ, sample points on the mesh, and export as XYZ, then use a tool like LASTools to convert XYZ to LAS.
• LASTools: Use txt2las to convert ASCII point data to LAS after extracting points from the OBJ mesh.

Best practices and tips

• Ensure your OBJ mesh is clean and free of errors before conversion.
• Choose an appropriate point sampling density to balance detail and file size.
• Check the coordinate system and units to ensure compatibility with your LAS workflow.

Summary

Converting OBJ to LAS enables the use of 3D mesh data in point cloud applications. CloudCompare is the best free tool for this conversion, offering direct mesh-to-point cloud sampling and LAS export.