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Geometry channel node

Uses a geometry object to choose a sop from which the channels will be created.

The Geometry chop uses a geometry object to choose a sop from which the channels will be created. The channels are created from the point attributes of a sop, such as the X, Y and Z of the point position.

The sop can select a subset of the points using Point Groups. The set of attributes that are converted to channels are chosen using the names of the attributes seen on the Info pop-up of sop tiles.

See the Channel SOP

Note

This chop works in tandem with the Geometry > Channel SOP. Point data can be modified in chops and then fed back to sops through the Channel sop, therefore be sure to take a look at the Channel sop description.

Parameters

Geometry

SOP

Retrieves the geometry from the SOP pointed to by this path.

Group

Fetch only the points within this point group. If blank, all points are fetched.

Method

The geometry fetch method.

Static

Creates one channel for each attribute, and all points use this channel (the first point resides at index 0, the next at 1, and so on). The length of the channels will be the number of points fetched.

Animated

Creates one channel per attribute per point. The channels show the animation of each point’s position/attribute values.

Attribute Scope

A string list of attributes to fetch from the SOP. The common attributes are:

P

point position (X, Y, Z) - 3 values

Pw

point weight with a value of 1

Cd

point color (red, green, blue) - 3 values

Alpha

point alpha with a value of 1

N

point normal value (X, Y, Z) - 3 values

uv

point texture coordinates (U,V,W) - 3 values

Rename Scope

The names to use for the newly fetched attributes. There must be one name per attribute, so an attribute scope of “P” should have a rename scope with three names (like tx ty tz).

Transform Object

If a transform object is specified, the point values will be represented relative to that object’s origin and rotation.

Organize by Attribute

(Applies to 'Animated Method' only) Will rebuild the fetched channels by the value of this attribute. A common example is the 'id' attribute found in particles. A channel is built for each unique id since the number of points may vary.

Channel

Start/End

The time range over which to fetch the geometry values when “Animated” Method is selected.

Sample Rate

The sample rate to use for the fetched channels.

Extend Left

The extend condition before the channel’s beginning.

Extend Right

The extend condition after the channel’s ending.

Default Value

The value of the default value extend condition.

Examples

The following examples are specifically designed to demonstrate this node:

Geometry

$HFS/mozilla/documents/examples/nodes/chop/geometry/Geometry.cmd

The following examples use this node:

BlendPoseBasic

$HFS/mozilla/documents/examples/nodes/chop/blendpose/BlendPoseBasic.cmd

BlobbySphere

$HFS/mozilla/documents/examples/nodes/sop/channel/BlobbySphere.cmd

CopyStamping

$HFS/mozilla/documents/examples/nodes/chop/copy/CopyStamping.cmd