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The Path object is a regular Geometry object with default geometry operators that define an oriented curve (path). This object should be created using the viewer Path tool. If it is created in Network View, then one needs to manually setup the paths inside this object’s points_merge geometry node.
The orientation is defined by the normals of the control vertices. The control vertices (PathCV objects) can be rotated by an arbitrary angle (even more than 360) and the orientation on the curve between the control vertices will be interpolated using a flexible rope metaphor.
The geometry created has normal and twist attributes. The normal specifies the orientation, while the twist attributes are used to determine the correct direction of the normal. The initial twist defines the path twist distribution at the path creation time. The twist defines the curve twist induced by the rotation of the handles after the path was created.
An oriented path created by the Path tool can be used, for example, in the Bones From Curve tool. The bones created from a path will flow naturally following the path orientation.
Parameters
Transform
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 visibitily if you do edit the node’s parameter interface.
Render
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.
Misc
Set Wireframe Color
Use the specified wireframe color
Wireframe Color
The display color of the object
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.
Shade Open Curves In Viewport
Any open curves contained in this object will be lit when the viewport is set to do so.
Turning this on will also use a GLSL shader better suited to hair if the whitehair
or guardhair
attributes are found in the geometry.
Curves with the width
attribute will also be rendered as thick ribbons with varying width in shaded modes.
Examples
PathPathcvWorm Example for Path object node
This example shows a use for the Path and Pathcv nodes. These Path CV’s can be rotated greater than 360. They also have an initial twist function under the controls tab. This can be useful for creating a quick spine.
The following examples include this node.
PathPathcvWorm Example for Path object node
See also |