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Rhino file at a glance

Software

Rhinoceros (Rhino, Rhino3D)

Developer

Robert McNeel & Associates

Extensions

.3dm · also .3dmbak, .rws

Geometry

NURBS curves, surfaces, solids and meshes

Used in

Architecture, industrial design, jewelry, marine

3D InterOp
Read Write

Import of .3dm files

  • Building software that needs to read Rhino files?

    3D InterOp is an SDK that lets your application import Rhino 3DM files alongside 30+ CAD and BIM formats.
File type Extension Purpose

Rhino 3D Model

.3dm

Main model file with geometry and associated model data

Rhino 3D Model Backup

.3dmbak

Backup used to preserve earlier versions or recovery data

Rhino Worksession

.rws

Manages linked models and collaborative project references

  • Curves

    Lines, arcs, splines and NURBS curves

  • Surfaces

    NURBS surfaces for smooth freeform shapes

  • Polysurfaces and solids

    Joined surfaces that can form closed volumes

  • Meshes

    Polygonal shapes for rendering and printing

  • Points and point clouds

    Measured or constructed points

  • Model properties

    Layers, materials, views and annotations

Target format What is preserved

STEP, IGES, SAT

Exact NURBS and B-rep geometry, without Rhino-specific data

STL, OBJ

A polygon mesh: exact surfaces are approximated

DWG, DXF

2D and 3D drawing geometry

FBX, 3DS

Meshes for rendering, animation and real-time visualization

  • Spatial doesn’t provide a Rhino viewer or converter for end users. 3D InterOp is for software developers who want their own application to read Rhino files.
  • Assuming all data transfers

    Rhino files can contain curves, surfaces, solids, meshes, layers, annotations and materials. Not every target format supports the same information, so some of it may be simplified or dropped.

  • Surfaces vs solids

    A model may look closed on screen while still containing gaps, naked edges, overlapping surfaces or non-manifold conditions that break machining, simulation or 3D printing.

  • Mesh resolution on export

    When NURBS are exported to STL or OBJ, too low a resolution makes curves faceted, while too high a resolution creates huge files.

  • Expecting feature history

    Once geometry leaves Rhino, design intent, constraints and manufacturing metadata are difficult to reconstruct in another system.

  • 3DM

    The Rhino model file
    3DM
  • STEP (STP)

    ISO 10303 product data exchange
    STEP (STP)
  • SAT

    ACIS kernel format
    SAT
  • STL

    Triangle mesh for 3D printing
    STL
  • B-rep

    Exact boundary representation
    B-rep
  • Product · 3D InterOp

    3D InterOp for CAD applications

    Read and write 30+ CAD, BIM and mesh formats inside your own application.
  • Add Rhino import to your software

    Evaluate 3D InterOp on your own models with support from Spatial’s engineers.

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