Houdini 21.0 Nodes Geometry nodes

GLTF Character Import geometry node

Imports a skinned character with animation from a glTF file.

On this page
Since 21.0

This is a high-level node that combines the GLTF Skin Import and GLTF Animation Import SOPs to provide a full geometry-based character that can then be directly deformed using a Joint Deform SOP.

Parameters

Import

GLTF FIle

The path to the glTF file to import (*.gltf or *.glb).

Reload

Reloads the glTF file. This is useful if the glTF file has changed on disk.

Skin Geometry

Node ID

The ID of the glTF node that contains the skin and mesh to import. Because this node specifically imports skinned geometry, the glTF node must have both a mesh and skin.

Promote Point Attributes to Vertex

When turned on, imported point attributes (excluding certain attributes that must remain point attributes such as P and boneCapture) are automatically promoted to vertex attributes.

Animation

Animation ID

The ID of the animation within the glTF file to import. If the animation has a name, it is displayed to the right of this parameter.

Skeleton Color

The point color used for the output skeleton’s Cd point attribute.

Timing

Method

The time units for specifying animation parameters.

By Time

The timing parameters below will be specified in seconds.

By Frame

The timing parameters below will be specified in frames.

Time

The time (in seconds) to import the animated pose from.

Animation Start

The time at which the source animation starts, when Method is set to By Time. Earlier poses will be clamped to this value. When turned off, this value is taken from the source animation where available. If it has no range information, Houdini’s scene start ($TSTART) value will be used.

Note that no clamping is done when this is turned off.

Animation End

The time at which the source animation ends, when Method is set to By Time. Later poses will be clamped to this value. When turned off, this value is taken from the source animation where available. If it has no range information, Houdini’s scene end ($TEND) value will be used.

Note that no clamping is done when this is turned off.

Playback Start

The destination time at which the specified animation will begin to playback, when Method is set to By Time. When turned off, Houdini’s scene start ($TSTART) value is used.

Frame

The frame number to import the animated pose from.

Animation Start

The frame at which the source animation starts, when Method is set to By Frame. Earlier poses will be clamped to this value. When turned off, this value is taken from the source animation where available. If it has no range information, Houdini’s scene start ($FSTART) value will be used.

Note that no clamping is done when this is turned off.

Animation End

The frame at which the source animation ends, when Method is set to By Frame. Later poses will be clamped to this value. When turned off, this value is taken from the source animation where available. If it has no range information, Houdini’s scene end ($FEND) value will be used.

Note that no clamping is done when this is turned off.

Playback Start

The destination frame at which the specified animation will begin to playback, when Method is set to By Frame. When turned off, Houdini’s scene start ($FSTART) value is used.

Speed

Sets the speed factor for the playback of the animation. This is applied after any clamping is performed by the Animation Start and Animation End parameters.

Attributes

boneCapture

This point attribute defines the rest transforms and skinning weights for the deformation. It is typically used by the Joint Deform SOP’s first input.

material_override

This primitive attribute holds the imported material property values suitable for use with Houdini’s viewport and the Principled Shader.

shop_materialpath

This primitive attribute specifies the path to a shader node used for rendering. When no shader node is available, a value of . tells the viewport to use the default shader with the values in the material_override attribute.

capt_names

This detail attribute holds a copy of the skin geometry’s bind pose influences from boneCapture.

capt_parents

This detail attribute provides parent indices for every entry in capt_names. An index of -1 means no parent.

capt_xforms

This detail attribute holds a copy of the bind pose transforms corresponding to capt_names. The 4×4 matrix values here are inverted from the ones found in boneCapture.

clipinfo

This detail attribute records the current animation range and sample rate, as well as the original animation range and sample rate of the imported animation.

name

Point attribute containing a unique name across all points used for identification. This is derived from the corresponding FBX node name. However, FBX node names may not be unique. For these cases, the names will be suffixed with 1, 2, 3, etc.

path

 point

Contains the hierarchical path to the FBX node that corresponds to the point. The ROP FBX Animation Output SOP uses this attribute when determining where to export the point’s transforms.

If the rest geometry input contains a primitive path attribute, it is also used similarly for creating the corresponding FBX node hierarchy. Furthermore, any intermediate nodes that start with LODGroup are created as an LODGroup FBX node instead of as a Null. This allows the meshes to be interpreted as LOD meshes by supporting applications like Unreal.

transform

This 3×3 matrix point attribute specifies the world transform for the point. While the world position of the point is still P, this transform encodes the world transform’s rotation, scale, and shear components.

gltf_animation_name

The name of the glTF animation. If this property is not set in the glTF file, this attribute will be empty.

Outputs

Rest Geometry

The character’s rest geometry.

Typically, this will contain polygons with the boneCapture point capture attribute, which can be deformed using the Joint Deform SOP.

Capture Pose

The character’s capture pose.

Each joint in the skeleton is represented by a point, where the P and transform (matrix3) attributes contain the joint’s transform. The point’s name attribute contains the joint’s name, and is matched up with the capture paths in the rest geometry’s boneCapture attribute when deforming the skin. The skeleton’s hierarchy is represented by two-point polygons between the points for each child joint and its parent.

Animated Pose

The character’s animated pose, which is represented in the same manner as the Capture Pose.

See also

Geometry nodes