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Your First Model

In this tutorial you'll build a rounded box with a circular pocket cut from the top. Along the way you'll learn the core workflow: sketch → extrude → modify.

Create a new file called box.fluid.js in your project folder.

Step 1: Import what you need​

import { sketch, extrude, cut, fillet } from 'fluidcad/core';
import { rect, circle, move } from 'fluidcad/core';

Everything you need comes from fluidcad/core. Later guides will introduce fluidcad/filters for advanced selections.

Step 2: Sketch a rectangle​

sketch("xy", () => {
    rect(100, 60)
})

sketch("xy", ...) opens a 2D drawing on the XY plane (the ground plane, looking down from above). Inside the callback, rect(100, 60) draws a rectangle that is 100 wide and 60 tall.

You should see a flat rectangle in your viewport.

Step 3: Extrude it into a box​

sketch("xy", () => {
    rect(100, 60)
})

const box = extrude(30)

extrude(30) pulls the sketch 30 units upward into a solid box.

Notice that we didn't pass the sketch to extrude() — FluidCAD automatically picks up the last sketch. Most operations work this way: extrude() grabs the last sketch, fillet() targets the last selection, and touching shapes auto-fuse into one solid. You can always be explicit when you need to, but smart defaults keep simple cases simple.

We save the result in box so we can reference its faces and edges later.

Step 4: Round the corners​

Let's make it nicer by rounding the rectangle's corners. Update the sketch:

sketch("xy", () => {
    rect(100, 60).center().radius(8)
})

const box = extrude(30)
  • .center() moves the rectangle so its center sits at the origin.
  • .radius(8) rounds all four corners with a radius of 8.

Step 5: Cut a pocket​

Now let's cut a circular pocket into the top. We sketch on the top face and then cut downward:

sketch(box.endFaces(), () => {
    circle(40)
})

cut(15)
  • box.endFaces() gives us the top face of the extrusion — we use it as the sketch plane.
  • circle(40) draws a circle with a diameter of 40, centered at the origin of that face.
  • cut(15) removes material 15 units deep. If you call cut() with no argument, it cuts all the way through.

Step 6: Fillet the bottom edges​

Finally, let's round the bottom edges of the box:

fillet(3, box.startEdges())

box.startEdges() selects the edges at the bottom (start) of the extrusion. fillet(3) rounds them with a radius of 3.

Full code​

Here's the complete model:

import { sketch, extrude, cut, fillet } from 'fluidcad/core';
import { rect, circle } from 'fluidcad/core';

sketch("xy", () => {
    rect(100, 60).center().radius(8)
})

const box = extrude(30)

sketch(box.endFaces(), () => {
    circle(40)
})

cut(15)

fillet(3, box.startEdges())

What you learned​

  • sketch(plane, callback) draws 2D shapes on a plane
  • extrude(distance) turns a sketch into a 3D solid
  • cut(depth) removes material from a solid
  • fillet(radius, edges) rounds edges
  • Operations like extrude return objects with methods like .endFaces() and .startEdges() that let you reference specific geometry
  • Most operations have smart defaults — extrude() picks up the last sketch, touching solids auto-fuse, and cut() with no argument cuts all the way through

You're ready to explore the Guides for deeper coverage of each feature.