Introduction
Every 3D model starts with a 2D sketch. A sketch draws flat shapes on a plane, which you can then extrude, cut, revolve, or sweep into 3D geometry.
Primitive Geometries
Primitive geometries are the building blocks of sketches — lines, arcs, and curves. They follow a "pen" model: each command starts from where the last one ended.
Compound Geometries
Compound geometries create complete, closed profiles in a single call. They are ready to extrude right away.
Trimming
trim() removes parts of intersecting geometry in a sketch. Draw overlapping shapes, then trim away the segments you don't need.
Constrained Geometry
Constrained geometry lets you create lines, arcs, and circles that are tangent to existing sketch elements. Instead of calculating positions and angles by hand, you describe the relationship you want and FluidCAD solves the geometry for you.
Offset
offset() creates a copy of sketch geometry shifted inward or outward by a given distance.
Projection
project() takes 3D geometry (faces, edges) and projects it onto your current sketch plane. This is useful for creating features that follow the shape of existing geometry.
Guides (Construction Geometry)
Sometimes you need geometry in a sketch just for reference — to position other shapes, define tangent lines, or set up construction lines — without including it in the final profile. The .guide() method marks any sketch element as construction geometry.