CadGaragePro 3D scans of trucks and 4x4s · 1:1 · mm

How to Use a 3D Scan in CAD: Import, Reduce, Model Around It

Updated · CadGaragePro

Import the STL as a mesh or graphics body, check its size and orientation against the scan extent we publish, then cut away everything except the area you are designing for. Model the bracket or bumper as normal CAD geometry from planes, section curves and points taken off the scan, instead of converting millions of triangles into a solid, which both Fusion and SOLIDWORKS limit.

What is the difference between a mesh scan and a CAD solid?

An STL file is a list of triangles and nothing else. Each facet is one normal vector and three corner points, stored in 50 bytes in a binary STL (Library of Congress), so a million triangles take about 50 MB. There are no CAD faces, edges or dimensions to edit, and FreeCAD’s documentation calls the format dimensionless (FreeCAD).

A CAD solid is a boundary representation (B-rep): every point on its faces is defined by an equation. On a mesh, what looks like a circle is many small triangles approximating one (SOLIDWORKS: Graphics and mesh BREP bodies). You can measure, section and pick vertices on a mesh (SOLIDWORKS: Mesh BREP workflows), but its faces have no parametric definition, so you cannot change a dimension such as a hole diameter (SOLIDWORKS: Mesh import options).

If you need CAD geometry rather than a mesh, we offer STEP files for the Jeep Wrangler JK and the Ford Ranger Next Gen (front, rear and chassis). STEP declares its units, and Rhino, for example, warns you when they differ from your document (Rhino 8 Help). What a STEP made from a scan can and cannot do is covered in STL vs STEP vs OBJ. The rest of this guide is about STL scans.

How do I import a large STL into SOLIDWORKS, Fusion, Onshape, FreeCAD or Rhino?

SoftwareCommandUnitsWhat matters for big files
SOLIDWORKS 2025File > Open, Files of type: Mesh Files, Options, Import as: Graphics Body (SOLIDWORKS: Mesh import options)Unit list in the same dialog; values are not convertedSolid or Surface Body import without mesh options makes one face per facet and is capped at 500,000 facets; graphics and mesh B-rep bodies warn above 5,000,000 facets (SOLIDWORKS: Mesh files)
FusionDesign workspace > Mesh tab > Create > Insert Mesh (Fusion: Insert Mesh)Unit Type: mm, cm, m, in or ftFlip Up Direction, Center and Move To Ground fix the position as you insert
OnshapeInsert new tab icon > Import (Onshape: Importing Files)Chosen on import, changeable later from the units menu in the tab (Onshape: Working with Imported CAD)4 GB upload limit per file; meshes can be viewed and referenced but not edited (Onshape: Working with Imported CAD)
FreeCADMesh workbench: Meshes > Import mesh… (FreeCAD: Mesh Import)None asked; STL is assumed to be mm (FreeCAD: Import from STL or OBJ)Creates a non-parametric mesh object
Rhino 8File > Import (Rhino: STL import/export)Shows the STL’s units if the file stores them and scales to the documentImports as a polygon mesh, not NURBS; can split disjoint pieces on import

SOLIDWORKS recommends graphics bodies because they import faster and can be converted to mesh B-rep later (SOLIDWORKS: Mesh files), so Graphics Body is the right first choice for a vehicle scan.

How do I work with a file of millions of triangles?

Start from the numbers. Compare a scan’s triangle count and file size with your software’s limits before you download it. Five scans from our catalog:

ScanTrianglesFile sizeScan extent, mm (in)
Toyota Hilux N80 tailgate1,521,72176.1 MB1,697 × 805 × 558 (66.8 × 31.7 × 22.0)
Ford Ranger Raptor PX3 bed and rear2,387,211119 MB2,532 × 2,031 × 1,478 (99.7 × 80.0 × 58.2)
Toyota Hilux N80 front section16,060,104803 MB2,062 × 1,895 × 1,718 (81.2 × 74.6 × 67.7)
Ford F-150 14th gen complete29,076,7021,454 MB5,886 × 2,441 × 2,006 (231.7 × 96.1 × 79.0)
Toyota Hilux N80 complete39,157,5461,958 MB5,321 × 1,904 × 1,918 (209.5 × 74.9 × 75.5)

The bottom three are all above the SOLIDWORKS 5,000,000-facet warning. Work them down in this order.

1. Cut out your region first. For a bumper keep the frame ends and front panel; for a rack keep the bed rails. In Fusion use Mesh > Modify > Plane Cut with Type set to Trim or Split Body (Fusion: Plane Cut). In Rhino, MeshSplit accepts IP for an infinite cutting plane (Rhino: MeshSplit). In FreeCAD use Meshes > Cutting > Trim mesh with a plane (FreeCAD: Mesh TrimByPlane). Or start smaller: the Hilux N80 is also sold as front, rear and tailgate sections.

2. Then decimate what is left.

SoftwareToolHow you set the reduction
SOLIDWORKSInsert > Mesh > Decimate Mesh (SOLIDWORKS: Decimate Mesh Body)Percentage, target facet count, or maximum deviation; graphics bodies only, and Paint Select Facets lets you decimate just part of the body (SOLIDWORKS: Decimating graphics mesh bodies)
FusionMesh > Modify > Reduce (Fusion: Reduce)Tolerance, Proportion or Face Count; Adaptive remesh keeps small faces where there is detail
FreeCADMeshes > Decimation… (FreeCAD: Mesh Decimating)Percentage with a tolerance, or an absolute face count
Rhino 8ReduceMesh (Rhino: ReduceMesh)Target polygon count or percentage; locked mesh points are not moved

Keep the mounting faces dense. In SOLIDWORKS, paint and decimate only the areas away from the mounts; in Rhino, lock the points around bolt faces and edges so the reduction does not move them.

3. Section instead of loading everything. A few planar cuts often give a bracket everything it needs. In Fusion, Mesh > Create > Create Mesh Section Sketch, then Fit Curves To Mesh Section, turns a cut into sketch curves (Fusion: Create Mesh Section Sketch). FreeCAD’s Meshes > Cutting > Cross-sections… makes a set of parallel sections on the XY, XZ or YZ plane with a count and spacing (FreeCAD: Mesh CrossSections). Rhino’s Contour command accepts meshes (Rhino: Contour).

Keep the untouched original file and use it at the end to check fit.

Why model around the scan instead of converting it?

A direct conversion turns each triangle into its own face. Rhino’s MeshToNURB makes one NURBS surface per mesh polygon (Rhino: MeshToNURB), and a SOLIDWORKS Solid Body import makes each facet a face, which can slow large models (SOLIDWORKS: Importing mesh files). Autodesk says Fusion converts best below 10,000 facets and may fail above that (Autodesk: converting a mesh to a solid), and lists too many mesh elements as a cause of slow models (Autodesk: slow models after inserting a mesh). The Hilux front section is about 1,600 times that guideline. FreeCAD can turn a mesh into a solid with Part > Create shape from mesh…, Refine shape and Convert to solid (FreeCAD: Part ShapeFromMesh), but its own tutorial notes the result has no history and no editable features (FreeCAD: Import from STL or OBJ).

The workflow that works:

  1. Set up references. Put planes on the vehicle centerline and on a datum such as the frame top. SOLIDWORKS lets you add reference planes and axes to mesh bodies and pick mesh vertices in sketches (SOLIDWORKS: Mesh BREP workflows). Onshape uses mesh points for planes, mate connectors and sketch projection with the Use tool (Onshape: Working with Imported CAD).
  2. Section at each mounting point: frame ends, bumper bolt faces, bed rail tops.
  3. Model the part as ordinary parametric geometry on those sections: plates, tubes, gussets.
  4. Check clearance against the mesh. SOLIDWORKS can detect interference and measure between mesh elements (SOLIDWORKS: Mesh BREP workflows).
  5. Confirm critical dimensions on the vehicle. Treat the scan as a reference, not a gauge: measure hole centers and frame widths on the truck before cutting steel.

Read the coverage note too. The Hilux N80 engine compartment scan shows the vehicle with the front bumper and crash carrier removed, and the Ford Bronco 6th gen scan shows the body with the doors and hardtop roof panels removed.

How do I check units and orientation?

STL coordinates are plain numbers, so the importer decides the unit. FreeCAD assumes millimeters; SOLIDWORKS, Fusion and Onshape let you pick a unit on import; Rhino scales by the units stored in the file when it has them. SOLIDWORKS does not convert values: import a meter-based file as millimeters and a 1 m edge measures 1 mm (SOLIDWORKS: Mesh import options). Measure the bounding box (in FreeCAD: Meshes > Analyze > Boundings info… (FreeCAD: Mesh BoundingBox)) and compare it with the scan extent we list. The complete Hilux N80 should measure 5,321 mm (209.5 in) along its longest side. If your number is off by a factor of 10, 1,000 or 25.4, re-import with another unit; 25.4 means an inch and millimeter mix-up.

For orientation, Fusion’s default modeling orientation is Z up, changeable to Y up in Preferences with a restart (Fusion preferences reference). If the truck lands on its nose or side, use Flip Up Direction in Insert Mesh, which swaps Y and Z, then Move To Ground. In other programs rotate it 90 degrees. Then align the length with one axis and the centerline with a plane, so left and right parts can be mirrored.

What mistakes cause the most trouble?

  • Opening a full scan as Solid Body in SOLIDWORKS. Without mesh body options it is capped at 500,000 facets; use Graphics Body.
  • Running Convert Mesh on a whole truck in Fusion. Convert a small trimmed piece, or nothing.
  • Decimating the whole truck uniformly before trimming. A heavy, even reduction can lose the hole edges and flanges you need to locate the part.
  • Picking the wrong unit. The part comes out 10, 25.4 or 1,000 times off.
  • Ignoring what was not scanned. The Mitsubishi L200 5th gen complete scan has no cabin interior.
  • Forgetting the real vehicle. Bumpers, bull bars and winch mounts attach to crash structures and can sit near airbag sensors, so follow the vehicle maker’s guidance and local road rules, and have structural welds done by a qualified welder.

Sources

Scans mentioned in this guide