Definition
3D CAD refers to a three-dimensional solid or surface geometric model of a part, typically represented internally as a boundary representation (B-rep). It is distinguished from 2D CAD, which produces flat drawings and sketches without a true 3D solid behind them.
Why 3D CAD matters for automation
Most modern manufacturing software, including feature recognition and CAM, requires a 3D CAD model as input; a 2D drawing alone, without an associated 3D model, usually has to be manually interpreted before it can be programmed.
Where this shows up
Implied whenever a part ships with a native 3D file (STEP, native CAD format) rather than only a 2D drawing or PDF.
Common mistakes
Treating a 3D-looking PDF or image as equivalent to a native 3D CAD file; only the latter carries the actual solid geometry that feature recognition and CAM software can operate on.
Most modern manufacturing software, including feature recognition and CAM, requires a 3D CAD model as input; a 2D drawing alone, without an associated 3D model, usually has to be manually interpreted before it can be programmed.
See how Blake reviews a partFrequently asked questions
Is a 3D PDF the same as 3D CAD?
No, a 3D PDF is a visualization; a native 3D CAD file (or a neutral format like STEP) carries the actual solid geometry software can operate on.
Can CAM work from a drawing alone?
Not directly; it needs a 3D model to generate toolpaths, so a drawing-only part usually gets modeled first.
What's the internal representation of a 3D CAD model?
Most commonly a boundary representation (B-rep), representing the part as a set of connected faces, edges and vertices.