A shopper uses her phone to see your ceramic table lamp in AR before buying. If the model is the wrong size, what she sees and what arrives won’t match, and there’s no warning on the screen.
When scanning products for e-commerce, size is the easiest thing to get wrong because a photo-based scan can’t tell how big anything is by itself. That’s why Shopify’s 3D guidelines require models at real-world scale. If you add a printed AprilTag to your product-shoot setup, Polycam Business and Enterprise will scale the model automatically, usually with better than 99% accuracy.
Key Takeaways
- Scanning a product uses the same setup as a product shoot: even light, a plain background, and photos from every angle.
- For AR, the model has to be the product's real size. On Polycam Business and Enterprise, one printed AprilTag in at least eight photos automatically scales the model.
- Shopify asks for GLB files of about 4 MB, with textures no larger than 2048 × 2048 px for mobile web.
- Glossy, clear, and very thin products are hard to scan with photos. Plan to source those models another way.
- What You'll Need
- A phone with the Polycam app
- A printed Polycam AprilTag sized to the product, mounted flat on cardstock or foam board
- A Polycam Business or Enterprise plan for automatic scaling
- Soft, even light and a plain, matte surface
- A Shopify store with a theme that supports 3D models
Why Size Matters More Than Looks in AR
A product photo can appear at any size on a screen without confusing anyone. In AR, the phone displays the model at the size set in the file, so shoppers imagine the real product that way. If a side table shows up a few inches short, it sets the wrong expectation before anyone checks the dimensions.
Shopify's 3D model checklist for partners puts it plainly: build the model at real-world scale, in the correct units, so it matches the real product's exact size. In AR, the model should be the same size as the product when you place it beside the real thing.
Photos capture shape and color but not size, so a photo-based model needs another way to get its scale. Before, you had to measure the product and set the scale by hand with the Rescale tool. Now, if you place a printed AprilTag next to the product, Polycam reads the tag’s size from the photos and automatically sizes the model to match.
How to Scan Products for E-Commerce, Step by Step
- Choose the tag size. For most tabletop products, use the 4 × 6 inch tag (A6 in metric). The smaller 2 × 3 inch tag is good for very small items. For furniture-sized products, pick a tag with a printed scale of 6 inches or more, like 8.5 × 11 inches (A4) or larger. If you’re unsure, use the bigger tag.
- Print the tag at 100% size. Turn off “Fit to page” and any other scaling options before printing. Measure the scale line under the tag with a ruler, and reprint if it doesn’t match the label. Printer settings can reset between jobs, so check each new batch.
- Set up your shot by placing the product on a plain, matte surface with soft, even light, just like you would for a white-background photo. Mount the tag flat on cardstock and place it next to the product where it’s visible from most angles. Only use one tag in the scene, or the scan won’t scale.
- Capture in Object Mode and choose photogrammetry (not Gaussian splats), since splat captures aren’t scaled. Walk slowly around the product at its height, then do a second circle from higher up to capture the top. Place the tag in front of the product so it appears in most photos. Make sure the tag is sharp and its corners are visible in at least eight photos taken from different angles.
- Check the size after processing. Measure one dimension on the model with the Ruler and compare it to the product’s spec sheet. If the tag was printed at 100%, kept flat, and included in at least eight photos, the model is usually more than 99% accurate.
Getting Product Scans Onto Shopify for AR
Shopify’s 3D model checklist asks for a GLB file that includes the model and its textures, and it has specific size limits. Try to aim for a total file size of about 4 MB, and keep textures at or below 2048 × 2048 px for mobile web, saving as optimized JPGs when possible. If your scan is larger, use Polycam’s Remesh tool to shrink it before exporting.
Your model must pass two checks in AR. Holes and open edges are visible when shoppers walk around the product, so seal them before exporting. Then test the file on a phone by placing it next to the real product and checking that their sizes match.
USDZ, the format used by Apple’s AR Quick Look, is only needed if your setup requires it and follows the same guidelines. To add the model, open the product in your Shopify admin and upload the GLB in the Media section. Your theme must support 3D models, and the number of 3D models you can upload depends on your Shopify plan.
Hard Cases When You Scan Products for E-Commerce
Photo-based scanning works best with matte surfaces and some texture. Glassware, chrome, and clear plastic often look warped or patchy. Very thin parts, like chair spindles or wire baskets, might not appear in the model at all. For these products, it’s usually faster to use a 3D artist or the manufacturer’s CAD file.
Wood, fabric, and matte ceramics scan well, so begin your catalog with those. If your first scans look good, only the difficult products will need an artist, so you’ll only pay per SKU when necessary.
Want to try it yourself?
FAQ
Can I 3D scan products for Shopify with my phone?
Yes. Capture the product in Object Mode with photogrammetry (not Gaussian splats), export a GLB, and add it to the product’s media. Shopify’s checklist asks for a GLB of about 4 MB at real-world scale, so use the Remesh tool in Polycam before exporting to reduce the file size. On Business and Enterprise, an AprilTag in the scan sets the scale automatically.
Why does my product look the wrong size in AR?
The model’s scale is off. A photo-based scan can’t know its size unless something in the scene provides a reference. On Polycam Business and Enterprise, include one printed AprilTag in at least eight photos, and the model will scale automatically. Without a tag, set the scale by hand with the Rescale tool using a known dimension.
What file format does Shopify need for 3D models?
You can use a GLB, a single file that holds the model and its textures. Keep it to about 4 MB, with textures at or under 2048 × 2048 px for mobile web. You only need USDZ if your setup asks for it. Check Shopify's current requirements before you publish.
Do I need a 3D artist for every product?
Not for most products. Matte, textured items like furniture, ceramics, and soft goods scan well with a phone. Glossy, clear, or very thin products are still easier to have modeled. If you scan the rest yourself, you’ll only need an artist for the hard cases, so you pay for modeling only when scanning isn’t enough.
