Houdini 17.0 Nodes VOP nodes

Point Cloud Open VOP node

This node opens a point cloud file and searches for points around a source position.

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This VOP opens a point cloud file (.pc) and queues up access to the points centered around a certain location. The pcopen VOP invokes the underlying pcopen VEX function.

Inputs

file

The name of the file to load. Point cloud files use the .pc extension, but it is also possible to load geometry files as point clouds.

pchannel

The name of the channel in the texture which contains the position to be searched.

P

The query position. The search for points in the file will begin at this position.

nchannel

Optionally, a normal channel can be provided to restrict the point search to points whose normal aligns with the search normal N.

N

The query normal. Points with dot(N, Npoint) > cos(cone) will be queued, and unmatched points will be rejected.

radius

The maximum radius around P that should be searched. If you know that all query points will reside within a given radius, you can speed up the search by specifying the radius here.

maxpoints

The maximum number of points that will be returned.

cone

The maximum cone angle to be used when rejecting points given a search normal.

preload

A toggle to control whether the entire point cloud file is loaded into memory before performing searches. Disabling preloading will decrease performance but may improve memory use.

Outputs

handle

The point cloud handle, to be used as input for VOPs which use the point cloud such as pcfilter or pciterate.

Examples

The following examples include this node.

PointCloudIterateAverage Example for Point Cloud Iterate VOP node

This example shows how the pciterate vop can be used to average together points returned by pcopen. First, a point cloud is generated with a floating point "check" channel initialized to 1 inside a circle in the x-z plane. Then, the points are filtered in a shader by looping using the pciterate vop and averaging the value of the "check" channel. The point cloud used in the example is stored inside the asset as points.pc.

PointCloudLookup Example for Point Cloud Iterate VOP node

This example shows how to accomplish point cloud lookups for volumes using pcfilter and pciterate. It demonstrates how to iterate over and import values returned by a query.

See also

VOP nodes