3D for e-commerce4 min read
3D model accuracy tolerance for size, colour and materials
How close a commercial 3D model has to be on size, how close colour can get on a screen, where materials approximate, and the QA that catches errors.
By CharpstAR · 4 Oct 2023 · Updated 9 Oct 2026
Part of 3D models for e-commerce: the complete guide
A 3D model on a product page gives the customer the product's size, colour and material. Each is checked differently and held to a different tolerance. This is what we work to.
Dimensions
Size is the one that can be checked with a tape measure, and AR is why it has to be exact. Both mobile platforms place models at real-world scale. Scene Viewer on Android states that one unit in a glTF file equals one metre, so the model appears in the room at true scale, and AR Quick Look does the same on iOS.
In practice, the overall bounding dimensions of furniture and hard goods should match the manufacturer's stated dimensions to within a few millimetres. Where the two sources differ, we follow the technical drawing, because published dimensions are sometimes rounded or wrong. Internal dimensions that the customer will act on, such as a shelf gap, a seat height, a drawer opening or the inside width of a cabinet, get the same treatment. Mouldings, carvings and other decorative detail can be simplified, which is where most of the modelling time goes down.
Colour on screen
A render can get very close to a physical sample under a defined light. It can't guarantee a colour match on the customer's screen, for reasons outside the model. Displays differ, and phone screens apply their own processing. Ambient light in the customer's room changes how a colour is perceived. The physical product also looks different in daylight and under a warm bulb.
The standard we work to is that the model's colour is built from the real material reference, checked side by side against a physical sample under controlled light, and signed off by someone at the brand who has the sample in their hand. The page then states that screens vary and that samples are available.
Materials
Materials in a real-time viewer are a physical approximation. Modern rendering describes a surface with a set of properties, namely base colour, roughness, metalness and normal detail, and then simulates how light bounces off it. This handles most surfaces convincingly, including painted wood, powder-coated metal, leather, matte plastic and flat woven fabric.
Deep pile and loose weave give the most trouble. Boucle, high-pile velvet and chunky knit have real depth, and light behaves in three dimensions inside them, so a flat surface approximation flattens them. For these fabrics put a close-up photograph next to the viewer; adding geometry to the model doesn't fix it.
Furniture
Dining chair in bouclé
Cream bouclé, black legs.
Bouclé is the hard case. This dining chair is covered in it: open the fabric detail and judge how close a model in a web page gets to the cloth.
Translucent materials are also hard. Frosted glass, thin marble and some plastics let light pass through and scatter inside, which is expensive to compute and is often simplified in a real-time viewer.
Iridescent paints and metallic flake depend on viewing angle and light source in ways a screen can't fully reproduce.
Very fine repeating detail, such as fine mesh, perforation and thin wire, needs more geometry and texture resolution to resolve properly, and that raises load time. Scene Viewer's recommended ceiling is 100,000 triangles and a 10 megabyte file, so fine detail has to fit inside that budget.
What we check before a model is delivered
Our review runs in stages so that different people catch different mistakes.
| Stage | Who | What is checked |
|---|---|---|
| Reference intake | Us, with the client | Technical drawings, dimensions, material references, photographs from enough angles, variant list |
| Modelling | Modeller | Geometry built to the drawing, real-world scale, clean topology, sensible simplification |
| Internal QA | A second person who did not build the model | Dimensions measured against the source, silhouette compared with photographs, materials checked, file weight, how it behaves in AR |
| Client review | The brand | Someone who has handled the product signs off on colour, finish and proportion, with comments tied to the model |
| Revision | Modeller | Changes made, re-checked by QA before going back |
| Delivery | Us | Web-optimised files, correct scale in both AR formats, variants complete |
Internal QA is done by someone other than the modeller because the person who built a model stops noticing its errors. Colour and finish are decided in the client review, since the client is the only party holding the physical object.
Contura's Build Your Stove configurator was built from the CAD files Contura already had, and the same assets are placed in AR, so the dimensions a customer sees in the configurator and in their own room come from the manufacturer's drawings.
What accuracy is worth
Accurate size and colour on the page affect one kind of return, the product that arrives and doesn't match what the customer expected.
Sources
- Google, Scene Viewer documentation.
- Apple, AR Quick Look.
