Parameters ¶
Transform ¶
Note
The transform of objects are also determined by the presence of any added node properties.
Transform Order
The left menu chooses the order in which transforms are applied (for example, scale, then rotate, then translate). This can change the position and orientation of the object, in the same way that going a block and turning east takes you to a different place than turning east and then going a block.
The right menu chooses the order in which to rotate around the X, Y, and Z axes. Certain orders can make character joint transforms easier to use, depending on the character.
Translate
Translation along XYZ axes.
Rotate
Degrees rotation about XYZ axes.
Scale
Non-uniform scaling about XYZ axes.
Pivot
Local origin of the object. See also setting the pivot point .
Uniform Scale
Scale the object uniformly along all three axes.
Modify Pre-Transform
This menu contains options for manipulating the pre-transform values. The pre-transform is an internal transform that is applied prior to the regular transform parameters. This allows you to change the frame of reference for the translate, rotate, scale parameter values below without changing the overall transform.
Clean Transform
This reverts the translate, rotate, scale parameters to their default values while maintaining the same overall transform.
Clean Translates
This sets the translate parameter to (0, 0, 0) while maintaining the same overall transform.
Clean Rotates
This sets the rotate parameter to (0, 0, 0) while maintaining the same overall transform.
Clean Scales
This sets the scale parameter to (1, 1, 1) while maintaining the same overall transform.
Extract Pre-transform
This removes the pre-transform by setting the translate, rotate, and scale parameters in order to maintain the same overall transform. Note that if there were shears in the pre-transform, it can not be completely removed.
Reset Pre-transform
This completely removes the pre-transform without changing any parameters. This will change the overall transform of the object if there are any non-default values in the translate, rotate, and scale parameters.
Keep Position When Parenting
When the object is re-parented, maintain its current world position by changing the object’s transform parameters.
Child Compensation
When the object is being transformed, maintain the current world transforms of its children by changing their transform parameters.
Enable Constraints
Enable Constraints Network on the object.
Constraints
Path to a CHOP Constraints Network. See also creating constraints.
Tip
You can you use the Constraints drop down button to activate one of the Constraints Shelf Tool. If you do so, the first pick session is filled automatically by nodes selected in the parameter panel.
Note
Lookat and Follow Path parameters on object nodes are deprecated in favor of 
Look At and 
Follow Path constraints.
The parameters are only hidden for now and you can set their visibility if you do edit the node’s parameter interface.
Subnet ¶
Input Labels
Labels for the four inputs to the subnetwork. These labels appear when you press MMB on the input connections. This is useful to document the purpose of each input.
Display
Whether or not this object is displayed in the viewport and rendered. Turn on the checkbox to have Houdini use this parameter, then set the value to 0 to hide the object in the viewport and not render it, or 1 to show and render the object. If the checkbox is off, Houdini ignores the value.
Output Transform
The object inside the subnet from which to get the subnet’s output transform, or one of the inputs to use as the parent.
Note
The local transform of the subnet is currently always the transform computed from its transform parameters. So it may be inconsistent with its world transform when this is set to a child object.
Visible children
Space separated list of objects inside the subnet to display. Use * to make all objects visible (the default). You can use wildcards and bundle references to specify objects.
This parameter lets you:
-
Quickly filter the visible objects based on an existing naming convention, for example
*_proxy. -
Control visibility of objects inside a locked digital asset where the display flags are not available.
Otherwise, in a normal subnet you can simply go into the subnet and set the 
display flag on objects.
Viewport Selecting Enabled
Object is capable of being picked in the viewport.
Select Script
Script to run when the object is picked in the viewport. See select scripts .
Cache Object Transform
Caches object transforms once Houdini calculates them. This is
especially useful for objects whose world space position is
expensive to calculate (such as 
Sticky objects),
and objects at the end of long parenting chains (such as
Bones). This option is turned on by default for Sticky and
Bone objects.
See the OBJ Caching section of the Houdini Preferences window for how to control the size of the object transform cache.
