Neighbor POP

Summary

The Neighbor POP uses the P attribute to find, for each point of the input, the closest points to it. It puts the indexes of the closest points in an array attribute Nebr. You specify the max number of neighbors, and you choose the Max Neighbors Distance to look for neighbors.

The size of the attribute Nebr is the Max Neighbors parameter. If fewer than that number is found, it puts a special number 4294967295 as the value for the neighbor index. The attribute NumNebrs holds the number of neighbors found for each point.

You can output the average distance to the found neighbors, optionally including the point's position. Alternately you can output the Inverse Distance Weighted Average, where the closest points have the highest influence on the average.

Instead of outputting the indexes of the neighbors, you can output any set of attributes of the neighbors (careful, this can produce a lot of data).

An alternate form of the Neighbor POP takes a second input, where the each point of the first input is compared to points of the second input.

Neighbors are determined by distance between points, but via the Neighbors Type menu, they can also be determined by connectivity along any primitive connecting edges to neighboring points (only one step currently). For example, two points adjacent to each other in a line strip or quad are neighbors of each other.

( Distribution - Default, Unique, Closest )

Internally it is using a unbounded spatial hashing algorithm nad put into one of Num Hash Buckets.

neighborPOP_Class

Parameters - Neighbor Page

Neighbors Type nebrtype - ⊞ - When checking for neighbors, choose to use edge connectivity or only distance to neighbor points.

• By Distance distance -

• Connected connected -

Max Neighbors Distance maxdistance - Specifies the distance below which a point is considered a neighbor of the current point.

Distribution distribution - ⊞ - Determines what kind of neighbor sets are returned.

• Default default -

• Unique unique -

• Closest closest -

Num Hash Buckets numhashbuckets - The number of buckets the points will be sorted in based on their position. A good heuristic is to choose it to be close to the number of points.

Output Hash Attrib outputhash - Whether to output an attribute with the Spatial Hash values, which can be useful to debug and optimize performance.

Output nebroutput - ⊞ - Whether to output the individual neighbors and their attributes in array attributes, or their average or distance weighted average.

• Neighbors nebr -

• Average avg -

• Inverse Distance Weighted Average weightedavg -

Max Neighbors maxneighbors - Specifies the max number of neighbors. This sets the array size of all the attributes storing neighbors information.

Neighbors nebrs - ⊞ - Enable addition of the neighbors attribute.

• Neighbors nebrs -

• Neighbor Attr Name nebrattrname - Name for the attribute containing the point indices of the neighbors.

Num Neighbors numnebrs - ⊞ - Enable the addition of the number of neighbors attribute.

• Num Neighbors numnebrs -

• Num Neighbors Attr Name numnbrsattrname - The attribute name for the number of neighbors.

Add Distance Attribute dodist - ⊞ - Whether to output an attribute containing the distance to the query point.

• Add Distance Attribute dodist -

• Distance Attribute Name distattrname - Specifies the scope of the attribute that stores the distance values

Max Neighbors for Average maxnebrsavg - Specifies the max number of neighbors considered when averaging neighbor attributes.

Include Query Point incquerypt - When on, includes the query point when calculating average when output is average.

Add Prefix addprefix - Whether to add Nebr prefix when outputting neighbor attributes.

Cast Integers to Floats castintstofloats - When averaging the neighbor attribute values, whether to cast integer attributes to float.

Neighbor Point Attributes nebrptattrs - ⊞ - Creates array attributes the size of max neighbors with the neighbor attributes for each point in the first input.

• * * -

Parameters - Common Page

Bypass bypass - Pass through the first input to the output unchanged.

Free Extra GPU Memory freeextragpumem - Free memory that has accumulated when output memory has grown and shrunk.

Delete Input Attributes delinputattrs - Only output which attributes you specify in this POP - helps isolate attributes into a separate branch.

Operator Inputs

• Input 0: -
• Input 1: -

Info CHOP Channels

Extra Information for the Neighbor POP can be accessed via an Info CHOP.

Common Operator Info Channels

• total_cooks - Number of times the operator has cooked since the process started.

• cook_time - Duration of the last cook in milliseconds.

• cook_frame - Frame number when this operator was last cooked relative to the component timeline.

• cook_abs_frame - Frame number when this operator was last cooked relative to the absolute time.

• cook_start_time - Time in milliseconds at which the operator started cooking in the frame it was cooked.

• cook_end_time - Time in milliseconds at which the operator finished cooking in the frame it was cooked.

• cooked_this_frame - 1 if operator was cooked this frame.

• warnings - Number of warnings in this operator if any.

• errors - Number of errors in this operator if any.

TouchDesigner Build: Latest\nwikieditor2025.30000

POPs (Point Operators) is a new Operator Family of TouchDesigner that runs on the GPU accelerated graphics card or chips, and creates/modifies 3D data which is rendered by the Render TOP or passed to devices like DMX lighting, LED arrays, lasers or other external systems.

Each SOP has a list of Points. Each point has an XYZ 3D position value plus other optional attributes. Each polygon Primitive is defined by a vertex list, which is list of point numbers.

Attributes are data associated with POP geometry. Points, Vertex (Vertices) and Primitives (polygons, lines, etc) can have any number of attributes.

An operator whose Bypass flag is set does nothing: All data going into its first input appears at its output unaffected.

The Graphics Processing Unit. This is the high-speed, many-core processor of the graphics card/chip that takes geometry, images and data from the CPU and creates images and processed data.

An Operator Family which operate on Channels (a sequence of numbers (Samples)) which are used for animation, audio, mathematics, simulation, logic, UI construction, and data streamed from/to devices and protocols.