Generate Sample Set

Categories

Geometry Queries

Description

Generates a data set of evenly distributed random locations on the input geometry. Locations are "glued" to the surface of a geometry so that they stay in the same relative position even as the geometry transforms and deforms, unless you recompute and reset the locations' values at different frames.

Parameters

Emission Type	Surface: generates the locations on the surface evenly. Point: generates the locations only on the geometry points. Volume: generates the locations evenly inside the volume defined by the geometry.
Rate Type	How to interpret the Rate value, when Emission Type is Surface or Volume. Number per Second: the value of the rate specifies the number of locations generated each second. Density per Second: the rate specifies the number of locations generated each second on each square unit of surface. This can be useful when generating locations on surfaces that are deformed so that the distribution doesn't get too sparse as the surface stretches out. With this option, you can turn on the Enable Max Number flag and specify the maximum number of locations generated. Number per Frame: the value of the rate specifies the number of locations generated each frame.
Point Rate Type	How to interpret the Rate value, when Emission Type is Point. Number per Second: the value of the rate specifies the number of locations generated per second. Number per Frame: the value of the rate specifies the number of locations generated each frame. All Points: generates a location at each geometric point. Rate is ignored.
Enable Max Number	Enables the Max Number setting (below). This option is available when Rate Type is Density per Second.
Max Number	The upper limit on the number of locations generated. This option is available when Rate Type is Density per Second. This is useful because the number of locations generated can become extremely large as the surface area gets large.
Reference	A reference to a weight map or other attribute on the emitter to filter locations by. If this option is used, the attribute is used to control the rate of emission across the geometry. If the emission type is set to "Surface", you can specify a portion of the surface; if the emission type is set to "Point", you can specify the points. The supported types for the attribute are: Boolean, integer and scalar. Integer and scalar values are clamped to a minimum of 0 and a maximum of 1. A value of 0 (or false for Boolean) means the corresponding vertex or triangle is discarded from the set of locations. Scalar values between 0 and 1 are used as weights when the emission type is set to Surface: a triangle will emit N% of the locations that it would have emitted without filtering where N is equal to the weight of the triangle multiplied by 100. The current attribute contexts supported when emitting from a surface are: vertex: the weight of a triangle is the average of the weights of its three vertices. polygon: the weight of a triangle is the value of the attribute at the center of the triangle. polynode: the weight of a triangle is the average of the weights of its three polynodes.
Explore	Click to select the reference from an explorer. You can only choose attributes that are valid at the generated locations.
Pick	Click to launch a picking session and select a reference from a viewport or explorer.
Invert	Inverts the effect of the filter, so that the actual filter will be 1 minus the value of the attribute.
Rate Control	How the rate is interpreted when a filter attribute is specified Exact Rate: the number of samples specified by the Rate value will be generated, but only where the filtering condition is satisfied. Proportional to Filtered Area: the number of locations specified by Rate will be generated across the entire surface or on all points, and then culled by the filtering condition. Note that this option is unavailable when Rate Type is Density per Second.

Ports

Inputs

Seed	Defines the sequence of random numbers used. If you require that two nodes generate different sets of values with the same parameters, simply assign them different seeds.
Time Varying	Whether to generate a different set of locations at each frame.
Geometry	The geometry on which we want to generate locations.
Rate	Affects the number of locations in the generated set. The interpretation of the rate depends on the Rate Type, as well as the Rate Control when a filter is specified.

Outputs

samples

A set of locations on the input geometry.