Houdini 20.0 Nodes Geometry nodes

Labs Straighten geometry node

Orients a mesh based on UP and FRONT groups

During photogrammetry workflows it is common to be faced with a mesh that is oriented arbitrarily.

Traditionally the best way of dealing with that is with a transform node and manually orienting the mesh and visually ensuring that it is oriented properly.

The Straighten SOP aims to assist in that workflow by letting the user define a group of polygons that are facing up, and an optional group of polygons facing forward.

The node will then figure out all of the appropriate rotations, in order for the average of the normals of the up group be facing up, and the same for the front group.


Selecting different disconnected areas that have similar normals helps with the orientation

Mesh before straightening

Mesh after straightening


Group Type

Type of Primitive for the group, Primitive, Edge or Point

Up Group

Group Name or Geometry Selection that defines what UP means in this mesh

Invert Up Axis

Toggle to orients the mesh towards -Y instead of +Y

Align Forward

Toggle to additionally orient the mesh forward as well as up. Controls the Y rotation of the mesh

Forward Group

Group Name or Geometry Selection that defines what FORWARD means in this mesh

Geometry nodes