Convert SLDPRT to 3DS

A legacy renderer, visualization application, or asset library may require the 3DS mesh format instead of an editable SolidWorks part. Converting the model also provides a portable asset for software that cannot open proprietary CAD files.

What SLDPRT contains

.sldprt is the native SolidWorks file extension for a single part. It can contain parametric features, sketches, dimensions, configurations, multiple solid or surface bodies, appearance data, and a feature history. SolidWorks users and mechanical, product, and manufacturing teams use it for editable CAD design.

An SLDPRT file is not normally a polygon mesh. Its exact contents depend on the SolidWorks version, selected configuration, external references, and suppression state. An assembly uses .sldasm, not .sldprt.

What 3DS contains

.3ds is the legacy 3D Studio binary scene format. It stores polygon meshes and can also store basic object names, materials, textures, cameras, and lights. Its broad support in older renderers, viewers, and asset libraries is its main practical advantage.

3DS is a poor replacement for CAD data: it does not preserve sketches, feature history, constraints, parametric dimensions, mates, equations, or editable solid topology. It also has legacy limits, including approximately 65,535 vertices and faces per mesh chunk and restrictive name and material conventions. Large or highly detailed parts may need to be split or simplified.

Direct conversion with CAD Exchanger

CAD Exchanger Desktop and Web are suitable when the source must remain SLDPRT and the destination must be 3DS. Confirm that the installed version or web service lists both .sldprt as an input and .3ds as an output; format availability can vary by product edition.

1. Open the SLDPRT file in CAD Exchanger and select the required SolidWorks configuration or body.
2. Check the model tree, units, orientation, colors, and visible or hidden bodies.
3. Choose Export or Save as, select 3DS, and configure tessellation. Use a smaller chordal deviation and suitable angular tolerance for curved or precision-critical surfaces; use coarser settings for a smaller rendering asset.
4. Enable separate objects or bodies when the destination needs independent selection. Export textures separately if the converter does not embed or copy them.
5. Open the result in the target application and inspect scale, normals, missing faces, material assignments, and mesh limits.

CrossManager is another established desktop CAD translator that may support this source-target pair in the applicable edition. Use its format list and conversion preview to verify SLDPRT-to-3DS support before purchasing or processing a batch.

SolidWorks and 3ds Max workflow

The standard 3ds Max installation should not be assumed to import SLDPRT directly. The old instruction to choose SolidWorks from 3ds Max's file-type list is version- or plug-in-specific and is not a reliable current procedure.

1. In SolidWorks, open the intended configuration and choose File → Save As.
2. For a CAD-preserving intermediate, export STEP and convert it with a translator that can tessellate STEP to 3DS. For a mesh workflow, export OBJ or STL when the SolidWorks version provides that option. OBJ generally carries more appearance information; STL carries geometry with little or no material data.
3. In 3ds Max, import the intermediate with File → Import → Import. Check import units and weld or smoothing options. STEP support may require a separate importer, whereas OBJ and STL are commonly supported.
4. After checking the mesh, use File → Export → Export Selected, choose 3D Studio (*.3DS), and set object, texture, smoothing, and coordinate options available in that exporter.

SolidWorks' tessellation settings affect mesh quality when exporting OBJ or STL. Increase resolution for fillets and curved surfaces, then inspect the result before the final 3DS export. Exporting through a mesh intermediate cannot restore CAD precision.

Online conversion considerations

Browser-based CAD Exchanger Web and other established CAD conversion services can be useful for occasional files, but upload only models permitted by the organization's confidentiality policy. Online services may impose file-size, conversion-time, account, or output-format restrictions, and external references or custom appearances may not be available to the converter.

Quality and compatibility checks

• Set the correct source and destination units. 3DS has limited unit metadata, so verify scale by measuring a known dimension after import.
• Use a tessellation tolerance fine enough for the smallest visible feature, but split or decimate very large meshes to avoid 3DS chunk limits.
• Check face winding, normals, gaps, thin walls, transparent materials, UV coordinates, and texture paths; these may change during CAD-to-mesh conversion.
• Remove hidden, construction, or suppressed bodies before export if they must not appear in the asset.
• Keep the original SLDPRT and an intermediate STEP, OBJ, or STL file. The 3DS file is a visualization mesh, not an editable CAD master.