Convert LAS to 3DM (Rhino)
This converter writes your LAS lidar points into a Rhino 7 .3dm file as a single PointCloud object, keeping RGB colour when the LAS point format has it. It does not build NURBS surfaces or a mesh, and clouds over a million points are thinned.
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What you get, and what 3DM does not get
LAS is the ASPRS exchange format for lidar: one record per return, with coordinates, intensity, classification, return numbers, GPS time and often RGB, plus a header describing scale factors and the coordinate reference system. Rhino works natively in .3dm, so handing a survey deliverable to a Rhino or Grasshopper user usually means a format change somewhere. On our servers, laspy reads the .las (LAZ is handled the same way), takes the point coordinates, and takes RGB where the point format carries it: formats 2, 3, 5, 7, 8 and 10. If the cloud holds more than 1,000,000 points, a uniform random sample of 1,000,000 points is kept and the rest are discarded; the page does not show a notice when that happens. The points are then handed to rhino3dm, which writes a Rhino 7 file containing one PointCloud object with those colours.
Be clear about the output before you plan work around it. 3DM is famous for NURBS, but nothing in this conversion creates a surface, a mesh or a solid: you get points. Intensity, classification, return number, GPS time, scan angle, per-point extra bytes, layer structure and materials are not carried into the .3dm, and neither is the LAS header's coordinate reference system - no projection or georeferencing information is written. If you need classification or intensity for analysis, keep working on the LAS and treat the .3dm as reference geometry.
Units are the other thing to check. No step in the chain converts units. rhino3dm writes the file with millimetres as the document unit, while LAS coordinates are usually metres (sometimes US survey feet), so a 60-metre facade arrives as 60 units and reads as 60 mm in a millimetre Rhino document. Set the document units you actually want, or scale the cloud by 1000, right after import. Orientation comes through as recorded on this path: Z stays up, with no 90-degree flip to correct.
How to convert a LAS scan for Rhino
- Export or keep the scan as .las or .laz from your processing software. Both are read here, and LAZ is usually a quarter of the size, which helps with the upload limits.
- Check the file against the per-file limit: 50 MB as a guest, 100 MB with a free account, 200 MB on Plus, 1 GB on Pro. Signed-in users with a file over 1 GB can use the pay-once large-file option for 3D conversions, which emails a link when it is done.
- If the cloud is far bigger than you need in Rhino, decimate it first in CloudCompare, LAStools or your scanner software, so you choose which points to keep instead of getting the automatic random 1,000,000-point sample.
- Upload the file and start the conversion. It runs on our servers, so no Rhino and no plugin are needed to produce the file.
- Download the .3dm and open it in Rhino 7 or later. Select the PointCloud, check its size against a known dimension, and scale or change the document units if the numbers came in as metres.
- If you need a surface, do that step in Rhino (Patch, MeshPatch, or a point-cloud plugin). This converter never meshes the cloud for you.
Conversion details
- Reads LAS and LAZ through laspy, including the compressed LAZ variant, with no need to decompress first.
- Keeps per-point RGB colour for LAS point formats 2, 3, 5, 7, 8 and 10; other point formats arrive without colour because the file never stored any.
- Writes a Rhino 7 .3dm containing one PointCloud object, which Rhino selects, moves and scales as a single entity.
- Automatically keeps a uniform random sample of 1,000,000 points when the cloud is larger, without showing a notice on the page.
- Orientation is preserved on this path - the cloud comes in upright, unlike mesh exports that pass through a Y-up stage.
- Download name matches your upload: yourscan.las becomes yourscan.3dm, with the link valid for about four hours.
Video Tutorial
An A-Z video guide on how to use MiConvert to change LAS format to 3DM. This is the safest method to convert data without needing to download any applications to your device. 🔗 Format conversion too
LAS to 3DM questions
Do I get NURBS surfaces or a mesh in the .3dm?
Neither. The .3dm holds one Rhino PointCloud object, with no surface fitting, no triangulation and no solid. Build the surface in Rhino from the imported points, or use a dedicated point-cloud-to-surface tool before converting.
Which Rhino versions can open the result?
The file is written as a Rhino 7 document, so Rhino 7 and later open it directly. Older releases may refuse a version 7 file, in which case open it in a newer Rhino and save back to the version you need.
Why does the cloud look tiny in Rhino?
Because no units are converted anywhere in the pipeline and the .3dm is written with millimetres as the document unit. LAS coordinates are typically metres, so they land as the same numbers read as millimetres. Change the document units to metres, or scale the PointCloud by 1000 after import.
Are classification, intensity and GPS time kept?
No. Only coordinates and RGB colour reach the .3dm. Classification, intensity, return numbers, scan angle, GPS time and extra bytes are left behind, and no coordinate reference system is written into the file. Keep the original LAS if you still need those attributes.
My scan is 800 MB. What are my options?
Convert it to LAZ, which usually fits a plan limit, or thin and tile it in LAStools or CloudCompare first. Per-file limits are 50 MB as a guest, 100 MB free, 200 MB Plus and 1 GB Pro.
Can I merge several LAS tiles into one 3DM?
Not here: a batch converts each uploaded file separately and produces one .3dm per input. Merge the tiles in CloudCompare, LAStools or your survey software first if you want a single Rhino point cloud.
Can you turn the lidar into a terrain surface instead?
Only through a different target. For terrain-like, height-field clouds we can grid the points and write a closed STL or 3MF, or an open surface as OFF or DAE. Object scans, building interiors and overlapping passes are refused for those targets, with an explanation, because there is no general reconstruction step here.
What happens to my file and the result?
The uploaded LAS is deleted as soon as the job finishes its last attempt. The .3dm stays available for about four hours behind a random download link, then it is deleted automatically. File names, sizes, formats and outcomes are logged, and signed-in accounts keep a conversion history entry.