Geometry & modeling
Feature tree
Definition
A feature tree is the ordered list of operations, such as sketches, extrudes, cuts, fillets, and patterns, that builds a parametric CAD model. Editing an early feature replays every feature after it, which makes controlled changes possible and also makes the model depend on each earlier step.
Also known as: feature history, design history, timeline, feature list, FeatureManager design tree
Updated
Different names, same idea#
Each CAD program names it differently. SolidWorks has the FeatureManager design tree, Fusion shows a timeline along the bottom of the screen, and Onshape has the Feature list. They all record the same thing: the sequence of modeling steps and the parameters of each step.
Rolling back and editing#
Because the model is rebuilt from the list, you can move a rollback marker to an earlier point and see the part as it was. Onshape's Feature tools documentation describes a Final button that shows the model from the bottom of the Feature list after all calculations, to check how an edit near the top affects the outcome.
Editing a feature changes its inputs, then every later feature is recalculated against the new result. When a later feature referenced a face, edge, or sketch that no longer exists in the same form, it fails or attaches to the wrong geometry.
Why a feature tree is valuable data#
A feature tree records how a shape was built, not just its final shape. The DeepCAD paper makes this point for machine learning: unlike meshes and point clouds, CAD models encode the creation process of 3D shapes. DeepCAD's dataset stores models as construction sequences for exactly that reason.
What exports keep#
Neutral formats such as STEP and IGES normally carry only the resulting geometry. The feature tree stays in the native file, which is why moving models between CAD systems usually loses editable history unless a dedicated migration tool rebuilds it.
Sources
Related terms
Parametric modeling
Parametric modeling builds a CAD model from dimensions, constraints, and an ordered list of features, so changing a value regenerates the geometry. It is the default approach in SolidWorks, Fusion, Onshape, Creo, NX, and FreeCAD Part Design.
Design intent
Design intent is the reasoning built into a model's structure: which dimensions drive others, what stays centered or symmetric, and what should move when something changes. Two models that look identical can behave very differently when edited because of how their intent was captured.
Sketch constraint
A sketch constraint is a rule applied to 2D sketch geometry, such as coincident, parallel, tangent, equal, or a fixed dimension. When a sketch is fully constrained, nothing in it can move freely, which makes later edits predictable.
DeepCAD dataset
The DeepCAD dataset is a public research dataset of 178,238 CAD models stored as sketch-and-extrude construction sequences, released with the ICCV 2021 DeepCAD paper. Much text-to-CAD research trains and benchmarks on it, and its simple geometry limits what those models learn.