Houdini 18.0 Nodes TOP nodes

Geometry Import TOP node

Load points or primitives from SOP or file geometry into work item attributes or a temporary file.

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What this node does can vary greatly based on the parameters.

The main parameters to set are Geometry source (where to load the geometry from), Store geometry as (where to write the geometry to disk, you can set this to "None" to not write to disk, or "Geometry Attribute" to store the native geometry in work items), and Class (whether to operate on points, primitives, bounding boxes, or "detail", meaning the whole geometry).

By default, this node loads the geometry whenever the node generates (including when you ask the network to generate static work items). If you intend to load files generated earlier in the network, turn on Load geometry during cook.

TOP Attributes

The geometry import TOP will create attributes on work items based on the attributes specified in the Copy Attributes parameter. In addition, it will also create several other attributes based on the Class of geometry being imported.

sopname

string

When loading geometry from a SOP Node, this attribute is set to the name of the node.

soppath

string

When loading geometry from a SOP Node, this attribute is set to the full path to the SOP.

*attribs

string array

A string array of attribute names is created for each of the element types: pointattribs, vertexattribs, primitiveattribs and detailattribs. If the geometry is being loaded a Detail then all four attributes will be created, otherwise only the attribute for the specified Class will be created.

When creating work items using All Groups or Specified Group, a <groupname>attribs attribute will be created containing the list of attributes on elements of the group.

groupname

string

When loading geometry elements from a particular group, this attribute will be set to the name of the group.

groupsize

integer

When creating work items from All Groups or Specified Group, this attribute is set to the size of the group.

*offset

integer

When loading points, vertices or primitives, the node will create a pointoffset, vertexoffset or primitiveoffset attribute that identifies the element in the source geometry.

point*

float array

When loading primitives with the Include Points from Primitives parameter enabled, a float array attribute will be created for each point in the primitive.

primitive

string

When loading primitives with the Include Points from Primitives parameter enabled, a string parameter with the full list of prim coordinates will be created.

pointcount

integer

When loading primitives, this attribute is set to the number of points in the primitive.

numpoints

integer

When loading the geometry as a full detail, this is the number of points in the geometry.

numvertices

integer

When loading the geometry as a full detail, this is the number of vertices in the geometry.

numprimitives

integer

When loading the geometry as a full detail, this is the number of primitives in the geometry.

minbounds

float array

When the Class parameter is set to Bounds, this attribute will contain the minimum x, y and z values of the geometry bounds.

maxbounds

float array

When the Class parameter is set to Bounds, this attribute will contain the maximum x, y and z values of the geometry bounds.

Parameters

Source

Geometry Source

Where to load the geometry from:

SOP Node

Enter the path to a SOP node in the current HIP file. This node will cook that node and store its output geometry. Note that you can use the Evaluation time parameter to cook the SOP node at a different point in the timeline.

Upstream Output File

Get the file path from the incoming work item’s output attribute and read the file in as geometry. This is useful, for example, to use a File Pattern node to generate work items representing geometry files and then load them in this node.

Upstream Geometry Data

Get the geometry data from an attribute on the incoming work item. For example, if it has geometry data loaded by a previous Geometry Import node.

Custom File Path

Load the geometry data from a file at a given path.

SOP Path

When Geometry source is "SOP Node", the network path of the SOP node to cook. For example, /obj/geo1/output1.

Evaluation Time

When Geometry source is "SOP Node", this parameter determines the time at which to cook the SOP (in seconds).

Work Item Frame

The SOP is evaluated at the frame value specified on the upstream work item.

Custom Time

The SOP is evaluated at the custom time value specified in the Custom Time parameter.

Houdini Time

The SOP is evaluated at the Houdini playbar time.

Custom Time

When Evaluation Time is set to "Custom Time", this parameter configure the item at which the target SOP node is evaluated.

Evaluate with Work Item Attributes

When Geometry source is "SOP Node", turn this on if the SOP network uses @attribute expressions to pull values from work items, for example for wedging. (If you use @attribute expressions, this node needs to cook the SOP separately for each work item. If you don’t, the node only has to cook the SOP once.)

File Tag

When Geometry source is "Upstream Output file", only load from file paths tagged with this file tag (for example, file/geo).

Attribute Name

When Geometry source is "Upstream geometry data", this parameter specifies the name of the attribute on the upstream work item that contains the geometry data. This should refer to a Geometry attribute.

Load Geometry During Cook

When Geometry source is not "SOP Node", load the geometry when each work item cooks. Turn this on if you need to load files that are generated earlier in the network. When this is off, the node loads the geometry when the work items generate (including when you request generation of static work items ahead of time) rather than when the work items run.

Merge Input Geometry

When Geometry source is "Upstream Output file", what to do if an upstream work item has more than one path in the output attribute. If this is on, the multiple files are merged into one piece of geometry. If this is off, the first input file or geometry source is used.

File Path

When Geometry source is "Custom file path", the file path of the geometry file to import.

Storage

Store Geometry As

Where to keep loaded geometry data:

None

Extract information from the geometry and store it as work item attributes, but don’t store the actual geometry data.

External File

Write the loaded geometry data to a file on disk.

Geometry Attribute

Save the the native Houdini geometry to the work item. The geometry will be stored in a geometry attribute on the work item. Currently the only node that can work with attached geometry is Invoke, or another Geometry Import.

Set Item Index To

How to

Element Index

For settings that generate new work items for each element (point, vertex, or primitive) in the geometry, set each work item’s index to the element number.

Upstream Item Index

Set each work item’s index to the upstream item’s index. For settings that generate multiple work items for each incoming work item, this will result in duplicate index values.

External File Path

When Store geometry as is "External file", the file path to write the geometry data to. This is set as the output file for the work items.

External File Tag

When Store geometry as is "External file", the file tag to apply to the output file.

Attribute Name

When Store geometry as is "Geometry Attribute", this parameter specifies the name of the attribute that the geometry should be stored to.

Data Extraction

Copy From Class

How to create work items from the loaded geometry: per point, vertex, primitive, or one work item for the entire geometry ("Detail"), or one work item with just the bounding box data of the entire geometry ("Bounds"). By default the node copies attributes from the geometry elements (or detail attributes for the whole geometry) onto the work items (see Copy attributes below).

Copy Attributes

When this is turned on, the node copies attributes from the loaded geometry elements (points, vertices, primitives, or detail attributes) onto the corresponding work items. The default is to copy all attributes (*). You can enter a space-separated list of patterns in the text field to specify which attributes to copy.

See the Attribute Pattern Syntax documentation for more details on how to write attribute patterns.

Include Bounding Box

Create minbounds and maxbounds attributes on each work item containing the bounding box of the corresponding geometry element.

Include Points from Primitives

When Class is "Primitive", create attributes on each work item containing the positions of the primitive’s points.

Create Work Item For

When Class is point, vertex, or primitive, how to handle geometry groups:

All Groups

Instead of creating a work item for each element, create a work item for each group.

Specified group

Create a single work item for the group(s) specified in the Group field.

Elements in Specified Group

Create a work item for each element in the group(s) specified in the Group field. If the Group field is blank, creates a work item for every element regardless of group (the default behavior).

Group

When Create work item for is "Specified group" or "Elements in specified group", this is a space-separated list of group names/patterns.

Examples

example_top_geometryimport Example for Geometry Import TOP node

This example demonstrates how to use geometry import to interact with SOP networks by creating a workitem per detail, primitive, point, or vertex.

See also

TOP nodes