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This partitions work items based on tiles so that each partition corresponds to a tile that contains work items with geometry that intersects with that tile. The tiles are arranged in a 3D grid, with origin at Tile Origin, where each axis has Tile Count number of tiles. Each tile has size per side calculated as Total Size / Tile Count. Tiles can be visualized as a grid of bounding boxes.
The source geometry is specified by attributes on each work item. The types of attribute data supported are points from string, points from vector, and bounding box. Points can be connected (i.e. a curve) or disconnected (point cloud), and points can be given a radius for size (i.e. sphere or tube).
Note that partitions are only created for tiles that contain or intersect with work item geometry. The resulting index of the partition corresponds to the tile index.
As an example, a Tile Count of 2×2×2 and a Total Size of 512 produces 8 axis-aligned bounding boxes, where each box is of size 256×256×256.
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
Tiles
Tile Origin
The offset of all tiles from world origin.
Tile Count
The number of tiles for each axis.
Total Size
The combined size of all tiles. To get a tile side’s size, the Total Size is divided by the Tile Count for that axis.
Tile Index Order
Specifies whether to use row-major or column-major for the tile indexing.
Write Tile Attributes
If enabled, writes out the tile origin, total tile size, tile count, intersecting tile’s position, intersecting tile’s minimum bounds, and intersecting tile’s maximum bounds. This can be useful for visualization.
Source
The source geometry is specified by attributes on work items.
Attribute Type
The type of attribute for the source geometry.
Points String:
Points are specified as a string attribute. Similar to the Coordinates
parameter in 
curve
Points Vector: Points are specified as a position vector. An example is the P attribute for position.
Bounding Box: The source geometry is a bounding box with min and max bounds.
Points Attribute
Specifies the name of the points attribute.
Points Connected
Specifies whether the points are connected (e.g. curve) or disconnected.
Point Radius
Specifies the radius of each point for intersection test.
Min Bounds Attribute
The name of the attribute for the minimum bounds.
Max Bounds Attribute
The name of the attribute for the maximum bounds.
Merge Attributes
These parameters control how attributes from input work items are merged onto the partitions produced by the node.
Merge Operations
Defines the number of attribute merge operations to perform on the partitioner node. The operations are used to merge attributes from work items in the partition onto the partition itself. Operations are performed in descending order. Attributes are merged using the first operation with a pattern that matches the attribute.
Apply Operation
Specifies the operation to perform to merge incoming attributes onto the partition. Each operation only applies only to the subset of attributes matched using the corresponding To Attributes parameter.
The following operations are available:
Ignore
Matching attributes are ignored and will not appear on the partition.
First Value
The value of each matching attribute on the first work item in the partition is kept, and values on subsequent work items are ignored
Last Value
The value of each matching attribute on the last work item in the partition is kept.
Unique Values
The unique values for each matching attribute are merged into an array. Duplicate values are discarded.
Append to Array
The values for each matching attribute are appended to an array for that attribute. All attribute values from all work items are kept.
Minimum
The minimum value for each matching attribute is kept.
Maximum
The maximum value for each matching attribute is kept.
Sum
The sum of the values in each matching attribute is stored on the partition.
Average
The average value of each matching attribute is stored on the partition.
Mode
The most common value in each matching attribute is kept.
Median
The middle value in each matching attribute is kept.
To Attributes
Specifies which attributes the corresponding Apply Operation parameter should apply to. This field can use the Attribute Pattern Syntax to specify multiple attributes.
Advanced
These are advanced parameters that provide finer control over the behavior of the partitioner.
Partition When
Determines when the partitioning step is performed on the input work items.
Input Items are Generated
Upstream work items are partitioned once all of them have been generated
Input Items Are Cooked
Upstream work items are partitioned once all of them are cooked. This may be required when the partitioning scheme is based on the results of the work items' execution.
This makes this partitioner behave like a 
Wait for All node except that it may create multiple partitions.A
Partition Target(s)
Determines which node or nodes(s) should target. Work items in the target nodes are partitioned as soon as they're generated even if the target nodes are not a direct input to this node. The descendants of the target work items are added to the partitions when they become available.
Direct Input Nodes
The partitioner uses work items from its direct input nodes. This is the default behavior
Upstream Static Nodes
The partitioner will skip over dynamic input nodes and partition work items from the nearest upstream static nodes.
Custom Target Node
The partitioner will use the node specified using the Custom Target Node parameter.
Custom Target Node
Specifies the target TOP node for the partition when Partition Targets is set to Custom Target Node. The partition scheme is applied to the work items in the target TOP node instead of this node’s input work items. The target TOP node must be in the same graph and above this node.
Split by Attribute
When on, the node splits input work items by the specified attribute(s) before partitioning them. The partitioning logic is evaluated on the list of work items for each distinct attribute value. Work items with different attribute values are always put into different partitions. Multiple attribute names can be specified as a space-separated list.
Missing Attribute
Determines how the node handles work items that are missing the split attribute.
This parameter is only available when Split by Attribute is on.
Ignore Work Item
Work items that are missing the split attribute are not put into any of the partitions.
Add Work Item to All Partitions
Work items that are missing the split attribute are put into all of the partitions.
Use Default Value
Work items that are missing the split attribute will use the value set by the Default Value parameter.
Default Value
Specifies the value to use for the split attribute for work items that are missing the attribute.
This parameter is only available when Missing Attribute is set to Use Default Value.
Allow Partial Matches
When Split by Attribute is set to a list of attribute names, this parameter determines how work items with only some of the attributes should be processed. If partial matches are enabled then work items will be added to split groups based on the attributes that do exist. Otherwise, work items with only a subset of the attributes will be excluded from the partitioning step.
Set Partition Frame To
Determines how the partitioner should set the frame value on partitions created by this node. If the partitioner already sets a custom frame value, for example like with a 
Python Partitioner SOP or 
Partition by Frame SOP, then this parameter has no effect.
None
No frame value is set on partitions.
First Work Item’s Frame
The frame value from the first work item based on the current Sort Contents By sort order is copied onto the partition.
Last Work Item’s Frame
The frame value from the last work item based on the current Sort Contents By sort order is copied onto the partition.
Largest Frame
The largest frame value from all work items in the partition is used for the partition’s frame.
Smallest Frame
The smallest frame value from all work items in the partition is used for the partition’s frame.
Sort Contents By
Determines the order that work items are sorted in when accessing the partitions on this node. This also affects the sort order of output files on the partition.
None
No sorting is applied. The work items in the partition are handled in no particular order.
Work Item Index
Work items in the partition are sorted based on their index.
Input Node Order
Work items in the partition are sorted based on the order of input nodes wired into this node. If two work items are from the same input, they are then sorted by index.
Attribute
Work items in the partition are sorted based on the attribute specified in the Sort Attribute field parameter.
Sort Direction
Determines whether the work items in this node’s partitions are sorted in ascending or descending order.
Sort Attribute
Specifies the name of the attribute to sort by.
This parameter is only available when Sort Contents By is set to Attribute.
Store Items to Attrib
When on, the list of IDs corresponding to the work items in the partition are written to the specified attribute. The work item IDs are stored as an integer array. This makes it easier to recover the list of partitioned work items downstream of the partitioner node.
Examples
PartitionByTile Example for Partition by Tile TOP node
This example demonstrates how to use the Partition by Tile TOP node.
| See also |
Partition by Bounds
