Add Parameters & Rules
Make a model respond to inputs with formulas and clear constraints
Overview
Parameters are the control surface of a configurator. This tutorial shows how to add inputs, calculate derived values, and use simple rules so the 3D model updates predictably.
Time
About 18 minutes
Level
Beginner
Goal
Inputs that drive dimensions and a few guardrails for valid configurations
Step 1: Add user inputs
Start with the values users should control directly. Typical first inputs are width, height, depth, material, and finish.
Step 2: Calculate derived values
Use formulas for values that should follow from the inputs. This keeps the public controls simple while the model still has the data it needs.
Example formulas
volume = length * width * height surfaceArea = 2 * (length * width + length * height + width * height) isLarge = IF(length > 1800 mm, TRUE, FALSE)
Step 3: Add rules
Rules turn formulas into product behavior. Use them to hide options, clamp values, change materials, or show warnings for invalid combinations.
Good first rules
Limit dimensions to manufacturable ranges, choose a default material, and expose only the options that apply to the selected product type.