Houdini 12 Basics

Parenting makes a child object’s transformations (moves, rotations, and scales) relative to those of a parent object.

Connecting the output of object A to the input of object B makes object A the parent of object B. For example, to view the scene from the point of view of a particular object, you can parent the camera to the POV object so the camera transforms with the object.

Note

In computer graphics parlance, we say that we “parented” B to A. This might seem backwards, but that’s the way it is.

An object which is parented to (that is, the child of) another object inherits the transformations of the parent object. Moving or rotating the parent moves/rotates the child as well.

You can also put objects inside an object subnetwork (use the tab menu to create a Subnet node at the object level). All objects inside the subnetwork inherit the transform of the subnet’s parent, if any.

Some other information is inherited from parent objects besides transformations. For example, motion blur can be inherited from a parent object. If the rendering parameters are not enabled for an object, they will be inherited from the parent object.

Each object can have only one parent, however the Blend object lets you blend between the transforms of multiple parents.

How to

To...Do this
Parent an object in the network editor

Parent an object in the 3D viewport
  1. Select the child object in the viewer.

  2. Click Parent in the Modify shelf.

  3. Select the parent object and press Enter.

Unparent an object in the network editor
Unparent an object in the 3D viewport
  1. Click the Parent tool on the Modify shelf tab.

  2. Select the child object(s) and press Enter.

  3. Select nothing and press Enter.

Note

Normally an object may “jump” position as it assumes its parent’s transforms. To prevent this, when you select the child object, turn on Keep position when parenting in the parameter editor before you parent it.