Houdini 20.5 Nodes Geometry nodes

Bone Deform geometry node

Uses capture attributes created from bones to deform geometry according to their movement.

This node type is deprecated. It is scheduled to be deleted in an upcoming revision of Houdini.

Replaced by new Bone Deform (bonedeform) SOP

(Since version 17.0.)

Tip

This node supports the character muscle/joint/etc. deformation workflow. To do a cage deformation of geometry, use the Lattice node.

Bone Deform works in conjunction with a Bone Capture nodes (Bone Capture, Bone Capture Proximity, Bone Capture Biharmonic) to deform geometry. As the bones move, this node displaces the points on the geometry according to the point weights.

Typically one or more Capture Regions are placed in an object (usually a bone) and named “capture_region”. The object is then read into a Capture operation through the object’s hierarchy. The object is moved to deform the Capture operation’s geometry with a Deform operation.

Deform can use Linear, Dual Quaternion or mix both solutions linearly to compute the deformation.

Parameters

Group

Optional point and/or primitive groups to limit the points which are deformed.

Skeleton Root Path

Specifies the parent OBJ for the bones attached to the input geometry. The pCaptSkelRoot detail attribute is used by default when this parameter is empty. If this parameter is non-empty, it overrides the pCaptSkelRoot detail attribute in the input geometry.

Transform Path

An optional path to a Motion FX node that contains channels for the world bone transforms, overriding the current state of the bones. In Motion FX the Extract Bone Transforms node can be used to capture the bone transforms.

Delete Capture Attributes

Delete point capture attributes to lighten the geometry data.

Delete Point Colors

Delete point color attribute to lighten the geometry data.

Deform Normals

Deforms the point normals to match the deformation of the points.

Normalize Weights

Normalizes the weights for each capture point so that they sum to 1 for deformation.

Fast Deform

This accelerates the deformation speed when the input geometry is not animated by using cached values for the capture attributes and undeformed point positions.

Assume Only Coordinate Changes In Input

Modifies the fast deform algorithm to assume that only point positions need to be re-cached when the input geometry has changed. Unpredictable results will occur with this enabled if attributes or topology changes.

Use Dual Quaternion Skinning

Enables the Dual Quaternion Skinning algorithm. Dual quaternion skinning is an alternate way of computing the deformation from bones. This method is better for deforming twisting geometry and preventing volume loss than the traditional Linear Skinning method. This is often used for body parts, such as the shoulders of characters.

Blend Dual Quaternion and Linear Skinning

Blends the deformation computed using both methods together based on a point attribute. If this checkbox is turned on, and if the Dual Quaternion Blend Attribute has a valid float point attribute, a linear blending of the point positions and normals is performed. A blend attribute value of 0.0, will use the Dual Quaternion solution. A blend attribute value of 1.0 will use the Linear solution. A blend value of 0.5 will mix both solutions together evenly.

Dual Quaternion Blend Attribute

The name of the point attribute to use when blending dual quaternion and linear solutions together.

Deform Vector Attributes

Deforms the vector attributes to match the deformation of the points.

Vector Attributes

Vector attributes to deform.

Deform Quaternion Attributes

Deforms the quaternion attributes to match the deformation of the points.

Quaternion Attributes

Quaternion attributes to deform.

See also

Geometry nodes