Parametric 3D configurators: one model, not a thousand variants

One evening, a cabinet maker sits at the kitchen table with a calculator. He sells cabinets in twenty widths, eight heights and six kinds of fronts. He wants a 3D configurator on his website. That's software where a customer builds their own cabinet and sees it in 3D. The agency he spoke to makes a separate model for every variant. That's twenty times eight times six. He looks at the number and puts the calculator down.

That's nine hundred and sixty models for one cabinet, and that's before handles, colours or interior layouts.

Counting variants

The cabinet maker's sum is completely normal. Every option multiplies the number of versions. A product with a few options and a handful of sizes quickly has hundreds of variants. A variant is one specific version of your product. Let the customer pick any size within a range, and in practice there are endless variants.

Building a separate model for each version isn't realistic. And if you do manage it, that's when the real problem starts. Every product change means updating all of those models. Whether 3D is even the right choice is covered in 2D vs 3D product configurators.

What parametric means

Parametric means a model is built from parameters and rules. Parameters are the sizes and choices, like width or colour. The rules decide what happens when a parameter changes. So instead of nine hundred and sixty cabinets, you build one cabinet that knows how it fits together. Think of a recipe: change the number of people, and the amount of every ingredient changes with it.

You may know the word from CAD. CAD is software engineers use to make technical drawings and 3D models. Engineers have modelled parametrically in CAD for a long time. There, it usually means a part updates when you change a size in the drawing. For a configurator in the browser, it means something similar, but with a different goal:

So a parametric web model isn't a copy of your CAD model. It's a light version that works the same way.

Rules instead of models

Take the cabinet. Instead of models, you write down rules:

• A bay is never wider than a set size. If the cabinet is wider, a divider is added.
• There's a shelf roughly every so many centimetres of height.
• Width and height are free to choose, within a range.
• Above a certain height, the side panel gets thicker.
• One particular front is only available up to a certain width.

With a few rules, one model covers all nine hundred and sixty versions. It also covers every in-between size the cabinet maker doesn't offer yet. If you add an option, you add a rule, not a hundred new models.

This is at the heart of what makes mass customization possible. Mass customization means matching products to each customer's needs, while staying almost as efficient as mass production. How to set up the product itself in modules is covered in Variant management and modular design.

One rule set for price and visuals

This is where it gets interesting if you write quotes. The rules that drive the model are often the same rules that set the price. An extra divider doesn't just show up in 3D. It's also a part with a price. And a thicker side panel uses more material.

When the picture and the price come from the same rules, they can't drift apart. The customer sees what they pay for, and pays for what they see. When a rule changes, it changes in one place, for the model and the price at the same time. That also makes a parametric configurator a good base for a CPQ system. CPQ stands for Configure, Price, Quote: building the product, working out the price and making the quote. It's also a good base for linking to the system you already use for quotes.

Limits

Parametric isn't right for every product. It works best when:

• sizes fall within a range and follow clear rules
• the product is made of recognisable parts that behave in a predictable way
• the rules are known, or can be written down

It works less well when:

• the shape is freely designed for each order, without fixed logic
• it's mostly about looks, and every size needs its own design decision
• the product sells so rarely that the rules don't pay for themselves

There are limits in the browser too. A parametric model has to stay light enough to run smoothly on a phone. The technology is there. WebGL 2 is what browsers use to draw 3D. According to MDN, it has worked in all major browsers since September 2021. But a model with too much detail feels slow, no matter how clever the rules are.

What it asks of your CAD data

Your CAD stays the source. A parametric web model is built from your existing models or drawings, using the sizes in them. Here's what helps:

• Clear parts. A CAD model built from logical parts is easier to convert than one big solid block.
• Known size rules. Does your engineer know which sizes depend on which other sizes? Write that down. Those become the rules of the web model.
• An open format. You can store the web model as glTF. That's an open, royalty-free file format, so nobody charges you to use it. Since 2022 it has been an ISO standard, an official international standard. That keeps you free from any single vendor.
• An agreement on changes. When the CAD model changes, who makes sure the web model changes too?

How a CAD model becomes ready for the web, step by step, is covered in CAD to web 3D configurator. If you work in Three.js, Babylon.js or Verge3D, the same idea applies. These are tools for showing 3D on the web. The rules live outside the 3D shape and drive it.

The cabinet maker doesn't need nine hundred and sixty models. He needs one model, a handful of rules and someone who knows how his cabinet fits together. And he is that someone. On 3D & Development you can try a cabinet that builds itself from rules.

Want to know how many rules your product needs? Tell us what you make and which sizes and options you offer. Get in touch, or take a look at 3D & Development first.