Noise POP

Summary

The Noise POP affects every point with a noise field, which can be thought of as smooth, randomly-rising and falling values in 3D space.

By default the Noise POP moves every point's P attribute a distance in X, Y and Z based on the point's position in the noise space. You can visualize the field by sending a Grid POP into a Noise POP. Turn on the toggle parameter Compute Point Normals to see proper shading.

The Type menu lets you choose between Simplex, Perlin in 2-4 dimensions. Simplex has the least grid-like field appearance. The Period determines the approximate distance between two peaks in each dimension (if you set Harmonics to 0).

Harmonics adds more detail by adding to the field another half-period noise field, and recursively for the number of "harmonics". Harmonic Spread is the ratio of period of one applied harmonic to the next. Furthermore the entire noise field can be translated, rotated or scaled via the Transform page.

The noise field value averages 0 in X, Y and Z. The Amplitude and Exponent parameters affect the magnitude of the resulting value, and the Offset is added to the resulting noise values.

Output attributes - On the Output page, you can output and name the raw noise values to an attribute named Noise by default. Because the Noise Size menu parameter on the Noise page defaults to Scalar, the Noise attribute is a single scalar float.

If the Noise Size menu parameter is set to Vector, the Noise attribute is a 3-component float, or 4 if the Parameter Size is set to 4.

On the Output page you can also output several math functions that are derived from the noise field, like Gradient and Curl.

The Gradient is the rate-of-change of a scalar noise around each point in X Y and Z (aka the "first order derivative") and is a float3 named NoiseGradient

Curl is an expression of how much the slope twists around each point. A 3D Curl is a float3 named NoiseCurl. A 2D Curl is float2 named NoiseCurl2

If Combine Operation is Add (default) or Multiply, a float3 noise is always applied to P, even though the noise may be set to scalar. With Combine Attribute Scope, the noise can be applied to any scalar or vector attribute (one component to 4 components), and output to any new or existing attribute.

With Combine Entity you can instead combine the NoiseCurl with any attribute.

With Noise Size set to Vector, changing the Parameters Size to 2, 3 or 4 gives you individual parameter controls of Amplitude, Exponent and Offset per X Y Z W dimension.

To animate the noise, put something like absTime.seconds in any of the Translate or Translate 4D parameters on the Transform page.

Per-point mapping of parameters - The Noise POP has a Map page, which allows every point to get a different value for Amplitude, Offset, Exponent, Period, Harmonic Spread and Harmonic Gain 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 Random POP.

noisePOP_Class

Parameters - Noise Page

Noise Lookup Attribute noiselookupattrib - Point input attribute to use when computing the noise.

Type type - ⊞ - Determines the noise type.

• Perlin 2D (GPU) perlin2d -

• Perlin 3D (GPU) perlin3d -

• Perlin 4D (GPU) perlin4d -

• Simplex 2D (GPU) simplex2d -

• Simplex 3D (GPU) simplex3d -

• Simplex 4D (GPU) simplex4d -

Noise Size noisesize - ⊞ - Number of noise components to compute.

• 1 1 -

• 2 2 -

• 3 3 -

• 4 4 -

Seed seed - Numerical value that initializes the randomization.

Period period - Period (scale) of the noise field.

Harmonics harmon - The number of higher frequency components to layer on top of the base frequency. 0 harmonics give the base shape.

Harmonic Spread spread - The factor by which the frequency of a harmonic increases relative to the previous harmonic.

Harmonic Gain gain - Amplitude of the Harmonics layered on top of the base frequency.

Parameter Size parsize - ⊞ - Number of independent configurable parameter values.

• 1 1 -

• 2 2 -

• 3 3 -

• 4 4 -

Amplitude amp - The noise values amplitude (a scale on the values output).

Exponent exp - Sets the exponent. The internal value is raised by the power of the exponent

Offset offset - Adds an offset to the resulting value.

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

• Point point -

• Vertex vertex -

• Primitive primitive -

Group group - If there are input groups, specifying a group name in this field will cause this POP to act only upon the group specified.

Parameters - Transform Page

Transform Order xord - ⊞ - Sets the overall transform order for the transformations.

• Scale Rotate Translate srt -

• Scale Translate Rotate str -

• Rotate Scale Translate rst -

• Rotate Translate Scale rts -

• Translate Scale Rotate tsr -

• Translate Rotate Scale trs -

Rotate Order rord - ⊞ - Sets the order of the rotations within the overall transform order.

• Rx Ry Rz xyz -

• Rx Rz Ry xzy -

• Ry Rx Rz yxz -

• Ry Rz Rx yzx -

• Rz Rx Ry zxy -

• Rz Ry Rx zyx -

Translate t - ⊞ - Translate the points through the noise space.

• Translate tx -

• Translate ty -

• Translate tz -

Rotate r - ⊞ - Rotate the points around the corresponding X, Y and Z axes. Angles are given in degrees.

• Rotate rx -

• Rotate ry -

• Rotate rz -

Scale s - ⊞ - These three fields scale the Source geometry in the three axes.

• Scale sx -

• Scale sy -

• Scale sz -

Pivot p - ⊞ - The pivot point for the transform rotates and scales.

• Pivot px -

• Pivot py -

• Pivot pz -

Translate 4D t4d - Translates the points through the 4th noise dimension.

Parameters - Output Page

Noise noise - ⊞ - Enable the addition of the noise attribute.

• Noise noise -

• Noise Output Attribute Scope noiseoutputattscope - Output attribute scope for the noise, and based on the Noise Size parameter.

Gradient gradient - ⊞ - Whether to output the noise gradient.

• Gradient gradient -

• Gradient Output Attribute Scope gradientoutputattrscope - Attribute Scope for the noise gradient output. Gradient is the rate of change of the noise function in X, Y and Z.

Curl 3D curl3d - ⊞ - Whether to output the 3D curl of the noise.

• Curl 3D curl3d -

• Curl 3D Output Attribute Scope curl3doutputattscope - Sets the attribute scope when outputting 3D curl noise

Curl 2D curl2d - ⊞ - Whether to output the 2D curl of the noise.

• Curl 2D curl2d -

• Curl 2D Output Attribute Scope curl2doutputattscope - Sets the attribute scope when outputting 2D curl noise

Combine Operation combineop - ⊞ - Specify how to combine the output value with the combine attribute value.

• None none -

• Add add -

• Multiply mult -

• Translate along Normal translatealongnormal -

Combine Entity combineentity - ⊞ - Specify which computed value to use for the combine operation.

• Noise noise -

• Curl 3D curl3d -

• Curl 2D curl2d -

Combine Attribute Scope combineattrscope - Input attribute scope for the combine operation.

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.

Compute Point Normals computenormals - Whether to compute point normals as a post operation.

Mode mode - ⊞ - Selects the shape of the field.

• Performance performance -

• Quality quality -

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).

• period (Period) period -

• offset (Offset) offset -

• amp (Amplitude) amp -

• exp (Exponent) exp -

• spread (Harmonic Spread) spread -

• gain (Harmonic Gain) gain -

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 Noise 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.

TouchDesigner Build: Latest\nwikieditor2025.30000

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.

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.

Absolute Time starts counting from 0 when the TouchDesigner process starts, and is always increasing. It will pause if the Power 0/1 button at the top of the UI is Off.

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.

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 surface type in SOPs that includes polygon, curve (NURBS and Bezier), patch (NURBS and Bezier) and other basic shapes like sphere, tube and metaball. Points and Primitives are part of the Geometry Detail, which is a part of a SOP.

A Group in POPs and SOPs is a named subset of points or primitives. It is created with the Group POP or Group SOP. Numerous operations in POPs and SOPs (using a Group parameter) can be restricted to affect the points or primitives in selected groups, and not affect others.

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.