Houdini 20.5 Nodes TOP nodes

Partition by Bounds TOP node

Partitions source items spatially using the bounding items.

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Since 17.5

A partition is created for each bounds item, and includes all of the source items that overlap with that bounds item. This is done by comparing each source item with each bounds item, using the Compiled Block to do the test.

The default internal Compiled Block creates a Bounding Box for the bounds item to do the overlap test. This test can be overridden by specifying another external Compiled Block. The Compiled Block must return non-empty geometry if there is overlap. Therefore an empty geometry result means that there is no overlap.

Tip

The $HH/help/files/pdg_examples/top_roadbuilder example shows how you can use this node to determine which terrain tile(s) intersect an input road curve.

Parameters

Bounding Geometry Parms

Controls for specifying the geometry bounds for the intersection test.

Bounds Source

Determines how the node loads bounding geometry.

Upstream Geometry

Geometry comes from work items on the first input.

Bounding Box

Geometry is a custom generated box.

Bounding Sphere

Geometry is a custom generated sphere.

Invert Bounds

Inverts the notion of what it means to be inside the bounds. When on, partitions will contain all source geometry that is not entirely contained within the bounding region.

Check Bounds Against

Determines what elements in the source geometry are compared against the bounding region.

This parameter is only available when Bounds Source is set to Bounding Box or Bounding Sphere.

Size

The x, y, and z size of the bounding box or sphere.

Center

The center point of the bounding box or sphere.

Include Partially Contained Entities

When on, entities not completely encompassed by the bounding region will not be included in the partition.

Use Geometry As

Determines how the upstream geometry should be handled when performing intersections tests. For example, you can choose to intersect source geometry with a bound region around the bounds geometry, or directly with the bounding geometry itself.

Bounding Box

The bounding box around the bounds geometry is used for intersection tests.

Bounding Sphere

The bounding sphere around the bounds geometry is used for intersection tests.

Bounding Object

The bounds geometry itself with the source geometry is used for intersection tests. Note that this generally expensive, especially if the bounding geometry is complicated.

Bounding Volume

The bounding geometry is interpreted as volumes when performing intersection tests.

Orient Bounding Box

When on, an oriented bounding box is used instead of an axis-aligned bounding box.

This parameter is only available when Use Geometry As is set to Bounding Box.

Iso Surface

Configures the iso surface parameter for checking if a point is the volume.

This parameter is only available when Use Geometry As is set to Bounding Volume.

See /nodes/sop/groupcreate.html#iso for details.

Geometry Source

Determines where to load the geometry from.

SOP Node

Lets you specify the path to a SOP node in the current HIP file. This TOP node then cooks the SOP node and stores its output geometry.

Note

You can use the Evaluation Time parameter to cook the SOP node at a different point in the timeline.

Upstream Output File(s)

Gets the file path from the incoming work item’s output attribute and reads the file in as geometry. You can filter the files with the File Tag parameter. If multiple files are found with the same tag, then the Multiple Inputs parameter determines which files to import.

For example, this is useful when you want to use a File Pattern TOP node to generate work items representing geometry files and then load them into this node.

Upstream Geometry Attribute

Gets the geometry data from an attribute on the incoming work item. For example, this is useful when you have geometry data loaded by a previous Geometry Import TOP node.

Custom File Path

Loads the geometry data from the file located in the File Path file directory.

SOP Path

The network path of the SOP node to cook. For example, /obj/geo1/output1.

This parameter is only available when Geometry Source is set to SOP Node.

Evaluate with Work Item Attributes

Turn on when your SOP network uses @attribute expressions to pull values from work items (for example, like with wedging). If you use @attribute expressions, the node needs to cook the SOP separately for each work item. If you do not use @attribute expressions, the node only needs to cook the SOP once.

This parameter is only available when Geometry Source is set to SOP Node.

File Tag

Loads from only file paths tagged with this file tag. For example, file/geo.

This parameter is only available when Geometry Source is set to Upstream Output File.

Load Geometry During Cook

When on, loads the geometry when each work item cooks instead of when work items are generated. This is useful if you want to load geometry that is produced when an upstream work item cooks, or if the geometry files being loaded are large.

This parameter is not available when Geometry Source is set to SOP Node.

Merge Operation

Determines what to do if an upstream work item has multiple sources of geometry. If the Geometry Source parameter is set to Upstream Output Files you can use these options to merge the geometry files. Likewise, if Geometry Source is set to Upstream Geometry Attribute and the Attribute Name(s) parameter is set to a pattern, you can choose to merge that geometry.

Import First Geometry: The first valid geometry source is imported and any others are ignored.

Import and Merge All Files: If Geometry Source is set to Upstream Output Files all matching files are merged and imported as a single piece of geometry. If Geometry Source is set to Upstream Geometry Attribute and the input work item is a Partition, the geometry from each item in the partition is merged and imported.

File Path

The file path for the geometry file to import.

This parameter is only available when Geometry Source is set to Custom File Path.

Source Geometry Parms

The source geometry that will be tested for intersection.

Geometry Source

Determines where to load the geometry from.

SOP Node

Lets you specify the path to a SOP node in the current HIP file. This TOP node then cooks the SOP node and stores its output geometry.

Note

You can use the Evaluation Time parameter to cook the SOP node at a different point in the timeline.

Upstream Output File(s)

Gets the file path from the incoming work item’s output attribute and reads the file in as geometry. You can filter the files with the File Tag parameter. If multiple files are found with the same tag, then the Multiple Inputs parameter determines which files to import.

For example, this is useful when you want to use a File Pattern TOP node to generate work items representing geometry files and then load them into this node.

Upstream Geometry Attribute

Gets the geometry data from an attribute on the incoming work item. For example, this is useful when you have geometry data loaded by a previous Geometry Import TOP node.

Custom File Path

Loads the geometry data from the file located in the File Path file directory.

Pre-Process Geometry

Determines how the source geometry should be pre-processed before partitioning.

Use Geometry As Is

The source geometry is not changed, and is compared as-is against the bounding regions.

Convert to Bounds

The source geometry is converted to a bounding box before comparing with the bounding regions.

Convert to Polygons

The source geometry is converted to polygons before compaying with the bounding regions.

SOP Path

The network path of the SOP node to cook. For example, /obj/geo1/output1.

This parameter is only available when Geometry Source is set to SOP Node.

Evaluate with Work Item Attributes

Turn on when your SOP network uses @attribute expressions to pull values from work items (for example, like with wedging). If you use @attribute expressions, the node needs to cook the SOP separately for each work item. If you do not use @attribute expressions, the node only needs to cook the SOP once.

This parameter is only available when Geometry Source is set to SOP Node.

File Tag

Loads from only file paths tagged with this file tag. For example, file/geo.

This parameter is only available when Geometry Source is set to Upstream Output File.

Load Geometry During Cook

When on, loads the geometry when each work item cooks instead of when work items are generated. This is useful if you want to load geometry that is produced when an upstream work item cooks, or if the geometry files being loaded are large.

This parameter is not available when Geometry Source is set to SOP Node.

Merge Operation

Determines what to do if an upstream work item has multiple sources of geometry. If the Geometry Source parameter is set to Upstream Output Files you can use these options to merge the geometry files. Likewise, if Geometry Source is set to Upstream Geometry Attribute and the Attribute Name(s) parameter is set to a pattern, you can choose to merge that geometry.

Import First Geometry: The first valid geometry source is imported and any others are ignored.

Import and Merge All Files: If Geometry Source is set to Upstream Output Files all matching files are merged and imported as a single piece of geometry. If Geometry Source is set to Upstream Geometry Attribute and the input work item is a Partition, the geometry from each item in the partition is merged and imported.

File Path

The file path for the geometry file to import.

This parameter is only available when Geometry Source is set to Custom File Path.

Compiled Block Parms

This allows to override the default intersection test by specifying another Compiled Block.

Compiled Block

The Compiled Block used for the overlap test. The default Compiled Block uses a Bounding Box for the bounds item. The Compiled Block returns non-empty geometry if there is overlap. Therefore an empty geometry result means that there is no overlap.

Compiled Block Bounds

When using another Compiled Block, as an override, this should specify the Block Begin Compile’s Input Name, so it can be used to forward the bounds input items.

Compiled Block Source

When using another Compiled Block, as an override, this should specify the Block Begin Compile’s Input Name, so it can be used to forward the source input items.

Examples

PartitionByBounds Example for Partition by Bounds TOP node

This example demonstrates how to use the partition by bounds TOP node.

See also

TOP nodes