Programming in 3D: How Block Code Becomes Objects
Parametric Modeling and Boolean Operations
Parametric Modeling and Boolean Operations
In parametric modeling, you don't sculpt shapes by hand. You define them with numbers. A cube is a width, height, and depth. A sphere is a radius. A cylinder is a radius and a height. Change the numbers, change the shape.
This is parametric modeling. Every dimension is a parameter you control. Unlike sculpting where you push and pull, here you type numbers and the shape obeys. Tools like BlocksCAD let you set these parameters with visual blocks instead of typing code.
Primitives alone are boring. The magic happens when you combine them. Boolean operations are the three fundamental ways to merge two shapes into something new.
A coffee mug? Start with a cylinder. Cut out a smaller cylinder (difference) to hollow it. Add a torus for the handle (union). Every complex shape is just primitives combined with boolean operations.
Before you combine shapes, you need to position them. Three transforms control where every object sits in 3D space.
In code, transforms wrap around shapes. translate([10,0,0]) cube(5) means
"make a cube, then move it." If you rotate then translate, you get a different
result than translate then rotate. Experiment to see why!
The real magic of parametric modeling: define a variable once, use it everywhere. Change that one number and the whole model updates. Here's a simple bracket defined by just three parameters.
Need a bracket for a different bolt size? Change the hole radius. Need it stronger? Increase thickness. One model, infinite variations. Engineers use this approach to design parts that can be customized for any situation without starting over.
In BlocksCAD, you drag and drop visual blocks. Under the hood, each block maps directly to an OpenSCAD command. The blocks are the code, just in a visual form.
BlocksCAD lets beginners create 3D models without memorizing syntax. As students get comfortable, they can switch to text mode and see the OpenSCAD code their blocks generated. The transition from visual to text programming happens naturally.
You now understand how parametric modeling works: define shapes with numbers, combine them with boolean operations, and position them with transforms. This is exactly how BlocksCAD turns visual blocks into real 3D-printable objects.
Every 3D object starts as a primitive defined by numbers: width, height, depth, radius.
Union joins shapes. Difference cuts one from another. Intersection keeps only the overlap.
Translate moves, rotate spins, and scale stretches objects in 3D space.
Change one number and the entire model updates. That is the power of parametric design.
Visual blocks map directly to OpenSCAD text commands. The blocks are the code.
Put your new knowledge into practice!