Convert EASM to 3DS

Legacy visualization, animation, and manufacturing applications may require Autodesk 3D Studio files with the .3ds extension. Because EASM is a published eDrawings file rather than an editable CAD source, conversion normally requires the original assembly or an exported mesh.

What the EASM format is

EASM is the eDrawings assembly format from Dassault Systèmes SolidWorks. It is commonly published from a SolidWorks .sldasm assembly for design reviews, supplier communication, documentation, and distribution to users without a full CAD license.

An EASM can contain tessellated model geometry, component and assembly information, configurations or display states, exploded views, measurements, markups, and other viewing data. It does not normally contain the editable parametric features, constraints, and complete source relationships needed for ordinary CAD editing.

What the 3DS format is

3DS is Autodesk 3D Studio's legacy binary scene format. It can store polygon meshes, object names, basic materials, texture references, cameras, and lights, and is still accepted by some older rendering, animation, visualization, and game-development software.

Its compatibility is offset by legacy limitations: materials are less expressive than modern physically based formats, unit handling is inconsistent, scene metadata is limited, and individual meshes are subject to 16-bit index limits commonly associated with approximately 65,536 vertices or faces. Use .3ds only when the destination requires it; OBJ, FBX, glTF, or a native CAD format generally preserves more information.

How to convert EASM to 3DS

Preferred route: obtain the source CAD file

1. Ask the author for the SolidWorks assembly, normally .sldasm plus its referenced .sldprt files, or request a neutral file such as .step or .stp.
2. Open the source assembly in SolidWorks or another CAD application that can read it. Check the active configuration, suppressed components, orientation, units, and whether hidden components should be included.
3. Export a mesh format supported by the destination workflow, such as .stl or .obj. SolidWorks does not generally provide a direct EASM-to-3DS path, so the mesh may need to be opened in Blender or another polygon editor.
4. In Blender, import the mesh with File → Import → STL or the corresponding OBJ command, verify a known dimension, separate or join objects as required, and export with File → Export → 3D Studio (.3ds). Enable the built-in 3DS exporter if that menu is absent in the installed Blender version.

The source-file route provides better control over component selection and tessellation than a published EASM file. It may also preserve assembly components separately if the CAD exporter supports that behavior.

Fallback route: export the EASM as a mesh

1. Open the file in eDrawings Professional. The free eDrawings viewer can display many EASM files, but mesh export is generally a Professional feature and availability can vary by file permissions and software version.
2. Use the available File → Save As or export command to select STL (*.stl). Choose the required units and a fine enough deviation or resolution for curved surfaces. Binary STL keeps the file smaller but does not retain assembly metadata.
3. Import the STL into Blender using File → Import → STL.
4. Measure a known feature and correct the scene scale before export. STL has no reliable unit metadata, so a model can be interpreted at the wrong size even when its geometry is otherwise correct.
5. Export through File → Export → 3D Studio (.3ds). Apply transforms, export only the required objects, and recreate materials or texture assignments when necessary.

MeshLab and similar polygon editors can convert STL to 3DS, but Blender offers more control over scale, normals, object separation, materials, and texture paths. A reputable online service such as CloudConvert may convert .stl or .obj to .3ds when those formats are currently listed in its converter; such services generally do not interpret EASM directly.

Quality and compatibility limitations

• STL export discards parametric features, assembly constraints, configurations, dimensions, markups, and most assembly metadata. The result is a polygon mesh, not an editable SolidWorks assembly.
• Coarse tessellation produces faceted curved surfaces. Fine tessellation improves appearance but increases file size, processing time, and the risk of exceeding 3DS mesh limits. Split large objects before export when the destination reports vertex or face-limit errors.
• STL normally contains geometry only. Component names, colors, transparency, materials, cameras, and textures may need to be reconstructed manually. 3DS texture references also depend on external image files and their paths.
• EASM files can be password-protected or published without export permissions. If eDrawings Professional cannot save an STL, the reliable solution is to request the source assembly or a STEP, OBJ, or STL export from the file owner.
• Do not upload confidential engineering data to an online converter. Use local eDrawings Professional, SolidWorks, Blender, or another desktop tool when the model contains proprietary design information.