Houdini 20.5 Nodes Geometry nodes

USD Configure geometry node

Since 18.0

This node sets detail attributes that affect how LOPs will import this geometry as USD primitives using a SOP Import LOP, or when loading a geometry file from disk.

Parameters

Import Group

Turn this on and specify a group name (or a space-separated list of group syntax) to import. If you turn this on but leave the field blank, it imports all geometry.

Import Group Type

When enabled, specifies the whether the Import Group is a point or primitive group.

Import Path Prefix

If a prim being imported has an automatically generated name (like mesh_0) because it had no path primitive, or if it has a path primitive but the path is relative (does not start with /), the node automatically prefixes the name/path fragment with this path. This is a way of keeping “un-pathed” prims organized under a single branch. (See how to create geometry hierarchy.)

(The default is /$OS which puts “un-pathed” prims under a root prim with the name of this node.)

Layer Save Path

When turned on, sets the Save Path metadata for the layer containing the geometry to this file path. When you write out USD using a USD render node, the geometry is saved out to a .usd layer file using this file path (after output processing).

Sample Frame

Sets the Start Frame and End Frame metadata on the USD layer generated by importing this geometry. This value is particularly useful when combining a sequence of BGEO files into a value clip with the USD Stitch Clips ROP.

Primitive Definition

Parameters in this group guide the translation process in terms of how USD primitives are generated from the source SOP geometry.

Enable Packed USD Primitives

When enabled, the Packed USD Primitives setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigusdprims detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Packed USD Primitives

What to do with packed USD primitives in the imported SOP geometry.

Ignore

Ignore packed USD primitives in the source SOP geometry.

Overlay Transforms

Import the transformation of the packed USD primitive as an override (Over) prim. This makes it easy to transform the packed USD prims without unpacking them.

Overlay Transforms and Attributes

In addition to Overlay Transforms, point or primitive SOP attributes on the packed USD primitive are imported as primvars with constant interpolation.

Enable Other Primitives

When enabled, the Other Primitives setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigotherprims detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Other Primitives

What to do with regular non-packed primitives (points, curves, polygons, spheres, and so on).

Define

Create the USD prims for the imported geometry if they don’t already exist. This is the standard way to import geometry.

Overlay

Create the USD prims as overrides. They will only be visible as changes to any prims that exist at a lower level with the same paths. This may be useful where you only want to import and modify certain attributes from SOPs onto existing USD geometry.

Overlay Transforms

Like “Overlay”, but only imports transform data.

Enable Define Only Leaf Primitives

When enabled, the Define Only Leaf Primitives setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigdefineonlyleafprims detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Define Only Leaf Primitives

Author intermediate primitives (for example, any Xform prims created for the Import path prefix) as overrides instead of definitions. This means if they don’t match up with underlying prims in lower layers, the leaf prims won’t be added to the scene. This is useful if you only want to import the geometry if its ancestors already exist in the scene tree.

(Note that all of the data is still imported, it just may not be visible in the scene graph tree or the viewport.)

Enable Packed Primitives

When enabled, the Packed Primitives setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigpackedprims detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Packed Primitives

What to do with SOP-native packed primitives.

Create Xforms

Creates an Xform prim from the packed primitive’s transform and attributes, and the packed primitive’s geometry is imported underneath.

Create Native Instances

Import the geometry in packed primitives as instanceable references. This imports each piece as a prototype under a Prototypes prim under the Import Path Prefix prim.

Create Point Instancer

Import the geometry in packed primitives as point instanced geometry. This imports each unique piece as a prototype under the point instancer prim.

You can assign a SOP primitive attribute to the packed primitive named usdinstancerpath to specify the USD scene graph path of the instancer.

Unpack

Only imports the packed primitive’s geometry. Unlike the Create Xforms mode, this does not create any additional hierarchy, and is equivalent to unpacking the packed primitive prior to being imported. This can be useful for importing multiple pieces of geometry without merging their attributes.

Enable Agents

When enabled, the Agents setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigagents detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Agents

What to do with agent primitives. In all modes, a prim is created from the agent primitive’s transform and attributes, and the agent’s geometry and animation are imported underneath.

Create Instanced SkelRoots

Imports the agent’s skeleton and geometry as instanceable references to a SkelRoot prim enclosing the skeleton and skinned primitives. This imports each unique agent definition as a prototype under an agentdefinitions prim under the Import Path Prefix prim.

Create SkelRoots

Creates a SkelRoot prim enclosing the agent’s skeleton and skinned geometry, which is imported underneath. This will be less efficient than Create Instanced SkelRoots for a large crowd, but can be useful for e.g. importing a single character where instancing is unnecessary.

Create Instanced Skeletons

Imports the agent’s skeleton as an instanceable reference to a Skeleton prim. This imports each unique agent definition as a prototype under an agentdefinitions prim under the Import Path Prefix prim.

Create Skeletons

Imports the agent’s skeleton as a Skeleton prim under the agent’s Xform prim. This will be less efficient than Create Instanced Skeletons for a large crowd, but can be useful for e.g. importing a single character where instancing is unnecessary.

Create SkelAnimations

Only imports the agent’s joint animation, creating a SkelAnimation prim. This can be used to efficiently import a sequence of frames, since the agent’s skeleton and rest geometry are typically unchanged between frames.

Enable NURBS Curves

When enabled, the NURBS Curves setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfignurbscurves detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

NURBS Curves

What to do with NURBS curve primitives.

Convert to Basis Curves

Import the curves as a BasisCurves primitive. This only supports cubic curves, but is useful for rendering through Hydra.

Create NURBS Curves

Import the curves as a NurbsCurves primitive. This provides complete round-tripping of NURBS curves, but has limited support for rendering through Hydra.

Enable NURBS Surfaces

When enabled, the NURBS Surfaces setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfignurbssurfs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

NURBS Surfaces

What to do with NURBS surface primitives.

Convert to Meshes

Import the surface as a Mesh primitive, which can be useful for rendering through Hydra.

Create NURBS Patches

Import the surface as a NurbsPatch primitive. This can be useful for round-tripping of NURBS surfaces, but has limited support for rendering through Hydra.

Enable Kind Authoring

When enabled, the Kind Authoring setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigkindschema detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Kind Authoring

How to assign kinds to imported prims.

All Geometry is One Component

Set root primitives in the imported tree to Component. Do not set kinds on descendants.

Nested Groups and Components

Set leaf primitives in the imported tree to Component. Set branch primitives to Group.

Nested Assembly, Groups, and Components

Set root prims in the imported tree to Assembly. Set intermediate branch prims to Group. Set leaf prims to Component.

None

Do not set kinds on the imported prims.

Enable Path Attributes

When enabled, the Path Attributes setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigpathattr detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Path Attributes

A (comma or space-separated) list of names of SOP primitive string attributes to use to use as prim paths to put the SOP geometry into. The default is path,name. See geometry hierarchy above.

If the list has more than one attribute, the importer checks each attribute for the first non-empty value.

If the string value a full path, that path is used as the USD scene graph path for that primitive. If the string is a relative path (or just a name), the string is appended to the Import Path Prefix string to generate a full scene graph path.

If none of the listed attributes exist on a given SOP primitive, or all values are an empty string, the importer generates a name automatically (for example, sphere_0).

Enable Prefix Absolute Paths

When enabled, the Prefix Absolute Paths setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigprefixabsolutepaths detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Prefix Absolute Paths

Whether absolute path values from Path Attributes should be prefixed/parented or not. By default this is off and only relative path values are prefixed.

Enable Import HeightFields as Mesh

When enabled, the Import HeightFields as Mesh setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigheightfieldconvert detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Import HeightFields as Mesh

If the source SOP geometry contains a height field volume, it will be imported as polygonal mesh. Other layers will be imported as vertex primvar if the values are varying, or constant primvar if the values are constant.

Geometry Handling

These parameters provide options to alter the interpretation of the SOP geometry data.

Enable Treat Polygons as Subdivision Surfaces

When enabled, the Treat Polygons as Subdivision Surfaces setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigpolygonsassubd detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Treat Polygons as Subdivision Surfaces

For polygon meshes that are not already tagged with a subdivision scheme, author a subdivisionScheme attribute set to catmullClark. This will convert them to subdivision surfaces.

Enable Subdivision Group

When enabled, the Subdivision Group setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigsubdgroup detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Subdivision Group

If Treat Polygons as Subdivision Surfaces is on, only convert polygons in this primitive group into subdivision surfaces.

Enable Reverse Polygon Vertex Ordering

When enabled, the Reverse Polygon Vertex Ordering setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigreversepolygons detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Reverse Polygon Vertex Ordering

USD supports an orientation attribute on mesh primitives that indicates whether polygons have a left-handed or right-handed ordering, while SOP geometry is always left-handed ordering. When this option is on, the importer always reorders vertices (and associated primvars) to be right-handed.

This is useful when round tripping right-handed oriented polygons from USD into SOPs and back into USD. The data is always converted to a left handed ordering when importing it into SOPs. If you imported the polygons back into USD without this option, they would be left-handed, unlike the original.

Enable Set Missing Widths

When enabled, the Set Missing Widths setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigsetmissingwidths detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Set Missing Widths

USD has a fallback value of 1.0 for the width of Curves and Points, which is often far wider/thicker than desired. If the SOP geometry does not explicitly author width/pscale data, this control can be used instead to explicitly author a USD value.

Import Data

These parameters affect the conversion of SOP geometry attributes into USD attributes and primvars, and the choice between default and time sampled value authoring.

Author Time Samples

Whether values imported from SOPs should be authored as default values for the corresponding USD attributes, or as a time sample (at the time in the timeline).

(When the USD system is asked for an attribute value, it returns the default if no time samples exist on the attribute. Otherwise it returns a value interpolated from the time sample data.)

If SOP is Time Dependent

If the SOP node the geometry comes from is time-dependent (is animated or contains animated values), write time samples. Otherwise, write defaults.

If Not Specifically Excluded

Author all values as time samples except for attributes listed in the Single Value Attributes parameter.

Never

Author all values as defaults.

(This is the only parameter on this node you can’t pre-configure on the geometry with the USD Configure SOP. This is because it requires a “live” SOP, not just attribute values embedded in the geometry.)

Enable Set Default Primitive

When enabled, the Set Default Primitive setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigsetdefaultprim detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Set Default Primitive

TBD

Enable Topology Attributes

When enabled, the Topology Attributes setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigtopology detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Topology Attributes

Controls whether USD topology attributes should be authored as time sampled or default values.

The following attributes are treated as topology attributes:

Primitive Type

Attributes

PointBased

orientation

Mesh

faceVertexCounts, faceVertexIndices, and subdivision-related attributes

TetMesh

tetVertexIndices, surfaceFaceVertexIndices

NurbsPatch

uKnots, vKnots, and trimCurve attributes

Curves

curveVertexCounts

BasisCurves

type, basis, wrap

NurbsCurves

orders, ranges, knots

PointInstancer

protoIndices

GeomSubset

indices

Animated

If you know that topology is changing in the source geometry over time, choose this option to record topology attributes as time samples in the USD scene graph. Having animated topology can be very expensive during playback, so only use this option when necessary.

Static

Write topology attributes as default values. This can make playback much faster, but limits how the topology can change over time.

None

Do not author topology attributes.

This is useful when USD data is sent to SOPs for processing, then brought back into LOPs. Using this option tells the importer that the geometry topology has not changed in this process, so only the changing point positions or other primvars will be imported.

Enable Attributes

When enabled, the Attributes setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigattribs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Attributes

A space-separated list of attribute names/patterns specifying the SOP attributes to import into USD as primvars.

In addition to matching attribute names directly, there are some values with special meanings:

bounds

Authors the USD extent attribute using the calculated bounding box of the associated SOP geometry.

visibility

Authors the USD visibility attribute based on the value of the usdvisibility geometry attribute.

See importing attributes for information on how the importer converts certain well-known Houdini attributes to their USD equivalents.

Enable Indexed Attributes

When enabled, the Indexed Attributes setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigindexattribs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Indexed Attributes

A space-separated list of attribute names/patterns specifying the SOP attributes to import into USD as indexed primvars.

If a SOP attribute matches this pattern, the importer authors the primvar as an indexed array of values (that is, an array of values called primvars:‹name›, and an array of indices into those values called primvars:‹name›:indices).

Preparing an indexed primvar can be expensive for attributes that are not integers or strings. You should only use indexed primvars where it is likely to result in significant savings in storage size due to a small number of unique values being used across a large number of components.

Enable Import as Single Element Array

When enabled, the Import as Single Element Array setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigconstantattribs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Import as Single Element Array

A space-separated list of attribute names/patterns specifying the SOP attributes to import into USD as primvars with Constant interpolation (an array with a single value for the whole primitive), regardless of whether the SOP geometry attribute is a point, primitive, or vertex attribute. If multiple values could be chosen for a particular USD primitive, the importer chooses the first value it encounters. Importing as a single element array (versus Import as Single Value) can be useful since it allows the primvar’s interpolation to be overridden without changing the primvar’s type.

Enable Import as Single Value

When enabled, the Import as Single Value setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigscalarconstantattribs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Import as Single Value

A space-separated list of attribute names/patterns specifying the SOP attributes to import into USD as primvars with Constant interpolation and a single value for the whole primitive, regardless of whether the SOP geometry attribute is a point, primitive, or vertex attribute. If multiple values could be chosen for a particular USD primitive, the importer chooses the first value it encounters. This is the default behavior for how detail attributes are imported. This is similar to Import as Single Element Array, but the primvar’s type is a scalar value instead of an array with a single element (for example, vector3f instead of vector3f[]).

Enable Boolean Attributes

When enabled, the Boolean Attributes setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigboolattribs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Boolean Attributes

A space-separated list of attribute names/patterns specifying which integer SOP attributes should be converted to primvars of type bool.

Enable Unsigned 32-bit Attributes

When enabled, the Unsigned 32-bit Attributes setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfiguintattribs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Unsigned 32-bit Attributes

A space-separated list of attribute names/patterns specifying which integer SOP attributes should be converted to primvars of type uint.

Enable Unsigned 64-bit Attributes

When enabled, the Unsigned 64-bit Attributes setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfiguint64attribs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Unsigned 64-bit Attributes

A space-separated list of attribute names/patterns specifying which integer SOP attributes should be converted to primvars of type uint64.

Enable Set Default Values

When enabled, the Set Default Values setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigstaticattribs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Set Default Values

A space-separated list of attribute names/patterns specifying the SOP attributes to always author as default values for USD primvars (never time samples). This is the list of exclusions when Author Time Samples is set to If Not Specifically Excluded.

Enable Partition Attributes

When enabled, the Partition Attributes setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigpartitionattribs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Partition Attributes

A space-separated list of attribute names/patterns specifying which SOP primitive string attributes represent subsets of the geometry. For mesh and curve primitives, the importer puts elements with the same value for this attribute into their own geometry subsets.

The importer will try to set the subset name to the attribute value, but may need to change the name to make it a legal USD primitive name. The importer stores the raw attribute value on the geometry subset prim as Custom Data with the key partitionValue.

Enable Prefix Subsets with Attribute Name

When enabled, the Prefix Subsets with Attribute Name setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigprefixpartitionsubsets detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Prefix Subsets with Attribute Name

When creating subsets from Partition Attributes, the subsets are named by combining the attribute name with the partition attribute’s value (a string or integer). This avoids name collisions when multiple partition attributes contain the same values, but can be undesirable if precise control of the subset names is required. For string attributes, if this option is turned off, the attribute values are directly used as the subset names.

Enable Subset Groups

When enabled, the Subset Groups setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigsubsetgroups detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Subset Groups

A space-separated list of group names/patterns specifying SOP primitive groups. SOP polygon and curve primitives in each group are imported as a geometry subset, named for the group.

Enable USD Custom Attributes

When enabled, the USD Custom Attributes setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigcustomattribs detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

USD Custom Attributes

A space-separated list of attribute names/patterns specifying the SOP attributes to import into USD as attributes (rather than primvars).

Enable Translate UV Attribute to ST

When enabled, the Translate UV Attribute to ST setting is used when translating the SOP geometry to USD. Otherwise, the parameter’s default value is used unless a usdconfigtranslateuvtost detail attribute exists on the SOP geometry (for example, from the USD Configure SOP)

Translate UV Attribute to ST

When turned on, converts the SOP vertex attribute uv into a USD primvar called primvars:st. Whether you need to turn this on depends on the renderer you are using and how your shaders are authored. If you are rendering with Karma, leave this off.

(As of this writing there is no strict standard for texture coordinate naming in USD, but the use of st is a common convention, whereas in SOP geometry, using uv is the common convention.)

See also

Geometry nodes