Line Smooth POP

Summary

The Line Smooth POP smooths line strips by blending the positions of adjacent points along a line strip.

It blends based on a choice of two methods: In the Smooth by Edge Distance method you give it a distance and it will find the points within that distance along the edge in both directions and blend them using either a Gaussian weighting or a Box weighting. With the Gaussian weighting, points farther from the computed point are given a lower weight. With a Box weighting, all points that are found along the adjacent edges up to the specified distance are give equal weight in computing the resulting point position.

In the second Smooth by Point Steps method you give a number of adjacent points in each direction to include in the smoothing calculation. In this method, points that are far from a given points may be included in the smoothing.

In the End Points Fixed option, it assures that the original end points of each line strip do not move.

In the Pre-Divide stage, it optionally adds more points by subdividing, similar to how the Line Divide POP adds new points, and it can add points based on the curvature of adjacent points.

Per-point mapping of parameters - The Line Smooth POP has a Map page, which allows every point to get a different value for Edge Distance and Point Step Filter Size parameters. In this mechanism, a separate attribute in the input contains values that override (or add to / multiply by) the parameter value. See Mapping POP Attributes to Parameters.

See also Line Divide POP, Line Resample POP

linesmoothPOP_Class

Parameters - Line Smooth Page

Attribute Class attrclass - ⊞ - Makes the POP operate on point attributes, vertex attributes or primitive attributes where applicable.

• Point point -

• Vertex vertex -

Input Attribute Scope inputattrscope - Input's attributes you want to affect within the chosen attribute class, or attribute components.

Pre-Divide prediv - Enable preceding division

Max Distance maxdivdist - Maximum Distance between Points

Maximum Number of Vertices maxverts - Sets the number of vertices to be allocated. It should be bigger than the actual number of vertices created (visible in info popup). More vertices allocated use more GPU memory.

Filter Method filtermethod - ⊞ - Determines the line smoothing method.

• Smooth by Edge Distance dist -

• Smooth by Point Steps point -

Filter Type filtertype - ⊞ - Determines smoothing kernel type.

• Gaussian gaussian -

• Box box -

Edge Distance filterdist - When Smoothing by Edge Distance, this is how far to look in each direction along the adjacent edges to contribute to a smoothed position value.

Point Step Filter Size filtersize - Sets the number of points used by the smoothing kernel.

Effect effect - Determines the amount of smoothing applied

End Points Fixed endpointsfixed - Enable output of fixed endpoints

Output Attribute Scope outputattrscope - ⊞ - Name of attribute to output (can choose components of attribute), can choose from menu.

• P P -

• N N -

• Color Color -

• Color.rgb Color.rgb -

• Tex Tex -

• PointScale PointScale -

• LineWidth LineWidth -

Override Automatic Attribute overrideautoattr - Whether to override the kind of attribute automatically created based on the POP input and parameters. Allows to specify manually the type and number of components of the new attribute.

Attribute Type attrtype - ⊞ - The output attribute's data type, default float.

• float float -

• double double -

• int int -

• uint uint -

• Color color -

• Color (double) dcolor -

• Direction dir -

• Direction (double) ddir -

Components attrnumcomps - ⊞ - The number of components in the new custom attribute.

• 1 1 -

• 2 2 -

• 3 3 -

• 4 4 -

Default Value attrdefaultval - ⊞ - Default values of the output attribute components if they cannot be computed.

• Default Value attrdefaultval0 - Default value(s) of the attribute.

• Default Value attrdefaultval1 - Default value(s) of the attribute.

• Default Value attrdefaultval2 - Default value(s) of the attribute.

• Default Value attrdefaultval3 - Default value(s) of the attribute.

Parameters - Resample Page

Resample Method resamplemethod - ⊞ - Line strip resample method.

• None none -

• Distance between Points dist -

• By Curvature curvature -

Min Distance resamplemindist - The minimum distance between points in the output line strips.

Max Distance resamplemaxdist - Maximum Distance between Points

Min Max Bias resampleminmaxbias - Bias of point creation - more near the minimum or more near the maximum distance.

Max Tries for Binary Search maxtries - Max number of iterations for binary search when linearly resampling.

Parameters - Map Page

Mapping map - Start of Sequential Parameter Blocks for attribute-to-parameter mapping.

OP map0op - Source OP for parameter mapping. The default of _in0 means the input POP.

Element map0element - The attribute (or component of an attribute) that will be mapped to a parameter per-point.

Parameter map0parm - ⊞ - Parameter on the current POP that will be mapped from the Element (the attribute).

• filterdist (Edge Distance) filterdist -

• filtersize (Point Step Filter Size) filtersize -

Combine Operation map0combineop - ⊞ - Combine operation for attribute value with parameter value.

• Set set -

• Multiply mult -

• Add add -

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: -

Info CHOP Channels

Extra Information for the Line Smooth 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.

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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.

A sequence of vertices form a Polygon in a SOP. Each vertex is an integer index into the Point List, and each Point holds an XYZ position and attributes like Normals and Texture Coordinates.

A parameter in most CHOPs that restricts which channels of that CHOP will be affected. Normally all channels of a CHOP are affected by the operator. TOPs have Channel Mask, a similar feature.

A sequence of vertices form a Polygon in a SOP. Each vertex is an integer index into the Point List, and each Point holds an XYZ position and attributes like Normals and Texture Coordinates.

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.

Any of the procedural data operators. OPs do all the work in TouchDesigner. They "cook" and output data to other OPs, which ultimately result in new images, data and audio being generated. See Node.

Every operator in TouchDesigner has a set of control Parameters that can be integer or floating point numbers, menus, binary toggles, text strings or operator paths, which determine the output of the operator.

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

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

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.