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Description

The filter command filters keys across the current playRange on the selected properties of the selected modules using the current filter settings.

Shogun Post's filter command is a carefully crafted, flexible tool designed to address the particular challenges presented by noise commonly found in motion capture system output. The tool uses an adaptive recursive methodology that analyzes keyframes in sequence to isolate digital noise from the sharp translation and rotational transitions found in biomechanical motion. Many filters written for motion capture tools have been incapable of drawing such distinctions automatically, forcing artists into an unhappy choice between time-consuming manual filtering and indiscriminate automatic filtering that destroys the nuance in the performances.

Functional area

Data editing

Command syntax

Syntax

filter lightCutoff threshold[-selected] [-length integer] [-transWidth float] [-lightCutoff float] [-threshold float] [-weightedAverage] [-width integer] [-strength integer]  [-smoothInOut float]

Arguments

The effect of the filter is modified with the (optional) argument settings. You can alternatively use the equivalent flags (see examples below).

NameTypeRequiredComments
lightCutofffloat
Specifies the amount of variation (in mm) allowed in data.
A low value results in less allowed variation and thus more filtering.
thresholdfloat
Useful range 5 to 40 (approx). Scales the lightCutOff value relative to the velocity of the data being sampled.
A lower value increases the lightCutOff more slowly as velocity increases.

Flags

NameFlag argumentsArgument typeExclusive toComments
selected0Filter is applied only to the selected keys
length1integerSpecifies the number of keys that are sampled
transWidth1floatSpecifies the transition width
lightCutoff1floatSpecifies the amount of variation (in mm) allowed in data. A low value results in less allowed variation and thus more filtering.
threshold1floatScales the lightCutOff value relative to the velocity of the data being sampled.
A lower value increases the lightCutOff more slowly as velocity increases.
A higher value increases the lightCutOff more quickly as velocity increases.
weightedAverage0The filter uses a weighted average algorithm instead of Shogun's standard filter algorithm
width1integerOnly applies when weightedAverage is used.
Specifies the number of keys that are averaged.
strength1integerOnly applies when weightedAverage is used
Specifies the strength of the filter, for example, 3 = low, 5 = medium, 7 = high, 9 = very high, max is 10.
smoothInOut
floatRange is over 0 to .5 (50%), specifying the percent of the time range being filtered to smooth over.

Return value

void

Examples

// The following filter is a good, general purpose filter. 
// The selected properties of the selected modules are filtered
// using a cutoff value of .1 and a threshold of 35.
filter .1 35;

//Alternatively, you could achieve the same result using the
//following options.
filter -lightCutoff .1 -threshold 35;

Additional information

Related commands