How to Buy an Accurate 3D Scan of a Truck or 4x4

Buy a truck or 4x4 3D scan only when the listing names the vehicle that was scanned, says which areas are in the file and which are not, gives the triangle count and file size, states the units, and prints the measured length, width and height. Check that the coverage reaches the parts you design around, import at 1:1, and compare the size with your own truck before you cut metal.

The checklist

1. A real scan, not a model drawn by eye. The listing names one physical vehicle (year, cab, trim) and says what was not captured.
2. Coverage for your part. Mounting faces, frame, bed or roof: whatever your bumper, tray or rack bolts to or has to clear is in the file.
3. Units and scale. The listing says the file is in millimetres (or inches) at 1:1, because an STL file cannot say it.
4. Triangle count and file size that agree. A binary STL takes 50 bytes per triangle, so the two numbers check each other.
5. A measured extent. Length, width and height of the file, with what they include (mirrors, antenna, roof rails, spare wheel).
6. The right format. STL for a measured surface to design around, STEP when your CAD program needs solids or surfaces.
7. Same generation and front. A facelift changes the grille, lights and bumper mounts, so match the generation and the front, not only the model year.

Each point is explained below, then our own full-vehicle scans are listed with these numbers.

Is it a real scan or a modelled file?

A real scan is measured from one physical vehicle, so it shows that truck as it stood: panel gaps, a removed bumper, small gaps where the scanner could not reach. A model drawn by eye from photos or blueprints is made to look right, and its hidden parts (frame rails, body mounts, the underside of the bed) are usually simplified or missing. A printable scale model is thickened and simplified for a 3D printer. The signs on a listing and in its preview pictures are in real 3D scan vs artist model vs printable STL.

A CAD model can be accurate too, when it was built from measurements of the vehicle, for example surfaces fitted to a scan. Ask what it was made from: from 3D scan to CAD model explains what that work involves and when a scan is enough on its own.

What coverage do you need for a bumper, tray or rack?

A “complete” scan can still miss the one area you need. The factory bumper can hide the frame mounts, a closed hood hides the engine bay, and many exterior scans have no cabin interior. Read the listing’s coverage note, including what it says is not in the file.

For a bumper, the DIY bumper guide shows which files expose the mounting faces and what you still measure on the truck.

Is it 1:1, and in which units?

STL stores numbers without a unit, so the program that opens it picks one: FreeCAD, for example, reads STL as millimetres (FreeCAD). A listing has to say which unit the file uses. After import, measure one overall dimension: a result 25.4 times too large or too small means the file was read in the wrong unit, and a pickup about 220 mm long is a miniature, not a scan: the 5,321 mm (209.5 in) Hilux N80 below is 221.7 mm at 1:24. Every file in the table below is in millimetres at 1:1.

What do the triangle count and file size tell you?

A binary STL is an 80-byte header, a 4-byte triangle count and 50 bytes per triangle (Library of Congress), so a listing that gives both numbers can be checked. Our Hilux N80 full-vehicle scan has 39,157,546 triangles: 39,157,546 × 50 + 84 bytes is 1,957,877,384 bytes, exactly the size of its file (1,958 MB).

More triangles show finer detail and make a heavier file; they do not make the scan more accurate, and a model can be subdivided to any count. A full truck in our catalog runs from 4.4 million triangles (221 MB) to 41.2 million (2,060 MB). An online 3D viewer may show a lighter copy than the download: Sketchfab suggests reducing a scan to under a million faces for the web.

How do you check the measured extent against your truck?

The extent is the length, width and height of the file’s bounding box. A good listing prints it and says what sets each number: mirrors out or folded, a roof antenna, roof rails, a rear-door spare wheel. Compare it with your truck and with the maker’s figures before you design.

Our Jeep Gladiator JT scan is an example of why. Its length, 5,529 mm (217.7 in), is within 10 mm of Jeep’s 5,539 mm (218.0 in), but its height, 2,039 mm (80.3 in), is above Jeep’s 1,882 mm (74.1 in) for a hardtop Rubicon (Jeep), so ride height comes from your own truck, not from the file. Then check two or three points you can reach with a tape (frame rail ends, bumper bolt holes, bed rail length) against the file before cutting metal.

STL or STEP?

Scans come as STL (sometimes OBJ): a measured surface of triangles that you design around. STEP holds CAD solids and surfaces with units declared in the file, which some CAD programs need. A STEP made from a scan can be fitted surfaces or the same triangles wrapped as millions of flat faces, so ask which. The comparison is in STL vs STEP vs OBJ, and the which file do I need tool answers it for your vehicle and CAD program in three questions.

Where are truck 3D scans sold?

Vehicle files are sold on general 3D marketplaces such as CGTrader, the Sketchfab Store and Cults, on Etsy, and by scanning shops directly; GrabCAD shares free CAD files. Scans, artist models and printable models often sit side by side there, so judge each listing by the checklist above rather than by the store.

We sell our files on our Etsy shop and post free sample files on GrabCAD. Each product page on this site carries the numbers from this checklist. Files are delivered usually the same day; a file over 20 MB comes as a download link in Etsy messages.

Which full-vehicle scans do we sell?

Every scan below is one physical vehicle, in millimetres at 1:1. Each single-file scan is a binary STL of exactly 84 + 50 bytes per triangle; the two bundles’ totals also hold files the triangle column does not count (the Hilux N70’s grille and bumper scans, the Tacoma’s OBJ frame).

Every file we sell, including front, rear and part scans, STEP models and bumper plans, is listed under vehicles. If a listing does not answer a question from this checklist, message the shop on Etsy before you buy.

Sources

• STL (STereoLithography) File Format, Binary, Library of Congress
• Import from STL or OBJ, FreeCAD documentation
• How to Make Your Scans Look Great on Sketchfab, Sketchfab
• 2020 Jeep Gladiator Specifications, Stellantis Media
• CGTrader, Sketchfab Store, Cults and GrabCAD Library, the marketplaces named above