Repair polygonal models

Task	Operator
Consolidate points	Fuse.
Eliminate cracks	Poly Stitch
Create a fill polygon between edges.	Curve tool ( snap the points of the polyline to the edges you want to fill, close the curve to create a face). Poly Knit (creates triangles or quads between existing polygons). Poly Cap (select one edge of a loop to automatically fill the hole).

Geometry

Working with objects
Primitives
Points and vertices
Geometry attributes

Describes how Houdini represents geometry using details, primitives, points, vertices, and attributes.
Groups
Volumes

Create geometry
Edit geometry
Edit components
Reselect geometry

In Houdini you can not only edit the parameters of a surface node, you can reselect the geometry the operation applies to.
Polygon shelf tools

Tools on the Polygon tab let you modify polygons in the scene view.
Model shelf tools

Tools on the Model tab let you edit objects in the scene view.
"Box up" modeling
Mirror geometry across a symmetry plane
Repair polygonal models
Modeling aids
Trim NURBS surfaces

Import geometry from other objects
Create, edit, and use Null objects
"Curve up" modeling
Geometry appearance editor

The appearance editor mode of the data tree pane lets you edit various controls for object viewport/rendered appearance in one place.
Locking geometry nodes

Packed primitives
Looping in geometry networks
Compiled blocks

You can mark a chain of compilable SOPs as a compiled block which can execute much faster in parallel.
Modeling FAQ