Indoor Lighting

Slim VSL4U25D7535KBL 1.3' 4 FT LED Semi-Direct Suspended Mount Linear

Frank Allen

January 18,2023

Direct Lighting

Absolute Computes the absolute value of the argument.

Add Outputs the sum of its inputs.

Add Attribute Adds a new attribute.

Add Constant Adds the specified constant value to the incoming integer, float, vector or vector4 value.

Add Joint Adds a KineFX joint to the geometry.

Add Point Adds points to the geometry.

Add Point to Group Adds the point specified to the group given.

Add Primitive Adds primitives to the geometry.

Add Steer Force Multiply steerforce by steerweight attributes and normalize results by total steerweight.

Add Vertex Adds vertices to the geometry.

Add Wind Force Layers a wind force onto a simulation.

Advect by Volumes Advects a position by a set of volume primitives stored in a disk file.

Agent Clip Catalog Returns all of the animation clips that have been loaded for an agent primitive.

Agent Clip Length Returns the length (in seconds) of an agent’s animation clip.

Agent Clip Names Returns an agent primitive’s current animation clips.

Agent Clip Sample Samples an agent’s animation clip at a specific time.

Agent Clip Sample Rate Returns the sample rate of an agent’s animation clip.

Agent Clip Times Returns the current times for an agent primitive’s animation clips.

Agent Clip Weights Returns the blend weights for an agent primitive’s animation clips.

Agent Convert Transforms Converts transforms between local space and world space for an agent primitive.

Agent Layer Bindings Returns the transform that each shape in an agent’s layer is bound to.

Agent Layer Name Returns the names of the current layers or collision layers of an agent.

Agent Layer Shapes Returns the names of the shapes referenced by an agent primitive’s layer.

Agent Layers Returns all of the layers that have been loaded for an agent primitive.

Agent Rig Children Returns the child transforms of a transform in an agent primitive’s rig.

Agent Rig Find Finds the index of a transform in an agent primitive’s rig.

Agent Rig Parent Returns the parent transform of a transform in an agent primitive’s rig.

Agent Transform Count Returns the number of transforms in an agent primitive’s rig.

Agent Transform Names Returns the name of each transform in an agent primitive’s rig.

Agent Transforms Returns the current local or world space transforms of an agent primitive.

Align Computes a matrix representing the rotation around the axes normal to two vectors by the angle which is between the two vectors.

Alpha Mix Takes two values for alpha based on the surface orientation relative to the camera and blends between the two with a rolloff as the bias control, effectively removing the silhouettes of the geometry edges.

Ambient Generates a color using ambient lighting model calculation.

And Performs a logical and operation between its inputs and returns 1 or 0.

Anti-Aliased Flow Noise Generates anti-aliased (fractional brownian motion) noise by using the derivative information of the incoming position to compute band-limited noise.

Anti-Aliased Noise Generates anti-aliased noise by using the derivative information of the incoming position to compute band-limited noise.

Append Adds an item to an array or string.

Arctangent Performs the atan2() function

Array Contains Checks whether a value exists in an array.

Array Find Index Finds the first location of an item in an array or string.

Array Find Indices Finds all locations of an item in an array or string.

Array Length Produces the length of an array.

Average Outputs the average of its inputs.

Average Vector Component Computes the average value of a vector argument.

BSDF Tint Tints a BSDF with separate control over colorization and luminance.

Bake Exports Export shading for use in bake image planes

Bind Represents an attribute bound to VEX.

Bind Point Transform Binds a KineFX point transform with a point index.

Blend Regions Takes a float input as a bias to blend between three input regions.

Blend Transforms Blends between two KineFX transformation matrices.

Block Begin Marks the start of a code block.

Block Begin For Marks the start of a for loop block.

Block Begin For-Each Marks the start of a for-each loop block.

Block Begin If Marks the start of an if code block.

Block End Marks the end of a code block.

Block End Break-If Marks the end of a code block.

Block End While Marks the end of a while code block.

Bounding Box Returns two vectors representing the minimum and maximum corners of the bounding box for the specified geometry.

Box Clip Clips the line segment defined by p1 and p2 to the bounding box specified by the min and max corner points.

Boxes Generates repeating filtered squares.

Bricker Generates a brick pattern based on the parametric s and t coordinates.

Brushed Circles Outputs an angle that gives the appearance of a circular brush pattern when used with anisotropy direction.

Brushed Metal Shader A basic brushed metal shader.

Bump Noise Displaces surfaces along their normal using anti-aliased noise, and returns the displaced surface position, normal, and displacement amount.

Bump To Normal Map Compute a tangent-space normal map from a bump map

Burlap Generates a burlap displacement pattern useful for simulating rough cloth or weave patterns.

Burlap Pattern Returns float between 0 and 1 which defines a burlap pattern useful for simulating rough cloth or weave patterns.

COP Input Returns a pixel value in one of the 4 input COPs connected to the VEX COP.

CVEX Shader Builder A node that implements a CVEX shader using its children VOPs.

Car Paint Shader Simulates car paint with embedded metallic flakes and a coat layer.

Cavities Produces a surface displacement that simulates small surface damage using anti-aliased noise of various frequencies.

Ceiling Returns the smallest integer greater than or equal to the argument.

Cellular Cracks Generates a cellular crack displacement suitable for simulating skin, leather, dried earth, and all kinds of crusts.

Cellular Noise Computes 2D, anti-aliased cellular noise suitable for shading.

Character to String Converts an unicode codepoint to a UTF8 string.

Checkered Returns number between 0 and 1 which defines a checkered pattern useful for visualizing parametric or texture coordinates.

Clamp Clamps the input data between the minimum and maximum values.

Class Cast Downcasts a generic (anonymous) co-shader object to a specific co-shader

Classic Shader Flexible material including multiple reflection layers, subsurface scattering, refractions and displacement.

Classic Shader Core A powerful, highly flexible, generic surface shader with displacement.

Collide Geometry Collides the specified joint with the target geometry.

Color Correction Provides a means to change the hue, saturation, intensity, bias, gain and gamma of the input color.

Color Map Looks up a single sample of RGB or RGBA color from a disk image.

Color Mix Computes a blend (or a mix) of its two color inputs, and outputs the resulting color.

Combine Local Transform Combines local and parent KineFX transforms with scale inheritance.

Compare Compares two values and returns true or false.

Complement Computes the complement of the argument by subtracting the argument from 1.

Compute Lighting Computes lighting using Physically Based Rendering.

Compute Normal This node gives finer control over handling of the normal attribute in VOPs.

Compute Tangents Compute surface tangents in different ways.

Conductor Fresnel Outputs a physically correct reflection factor for conductive materials.

Conserve Energy Clamp the reflectivity of a bsdf to 1.

Constant Outputs a constant value of any VEX data type.

Contour Increases or decreases contrast for values at the bottom of the input range.

Copy Takes a single input of any data type.

Cosine Performs a cosine function.

Crackle Returns float between 0 and 1 which defines a crackle pattern useful for simulating the fine grain texture in skin or on a much larger scale dried mudflats.

Create Point Group Creates a new point group with the name specified.

Cross Product Computes the cross product between two vectors, defined as the vector perpendicular to both input vectors.

Curl Noise Creates divergence-free 3D noise using a curl function.

Curl Noise 2D Creates divergence-free 2D noise using a curl function.

Curvature Computes surface curvature.

Curve Solver Positions and orients KineFX points from a curve and a list of segment lengths.

Decal An OTL that performs composting of texture maps.

Depth Map Works on an image which was rendered as a z-depth image, returning the distance from the camera to the pixel (or plane) in question.

Determinant Computes the determinant of a 4×4 or 3×3 matrix.

Dictionary Keys Produces the keys of a dictionary.

Dictionary Length Produces the length of a dictionary.

Direct Lighting Internal VOP used to compute direct lighting.

Direction to Child Computes the direction to a KineFX joint’s child.

Direction to Parent Computes the direction to a KineFX joint’s parent

Dirt Mask Masks crevices or exposed edges

Displace Displaces surface position and modifies surface normals.

Displace Along Normal Displaces the surface along the surface normal by a given amount.

Displacement Texture Modifies normals and/or positions based on a texture map.

Distance Returns the distance between two 3D or 4D points.

Distance Point to Line Returns the closest distance between a point and a line segment defined by two end points.

Divide Outputs the result of dividing each input value by the next.

Divide Constant Divides the incoming integer, float, vector or vector4 value by the specified constant value.

Dot Product Computes the dot product between two vectors.

Dual Rest Outputs sanitized dual rest values based.

Dual Rest Solver Sanitizes dual rest attribute data for easier use.

Edge Falloff Creates a smooth roll-off of the input color from the center of the geometry to the edges, based on the surface normal.

Eggshell Pattern Returns a new surface normal (N) which has a slight fine grained bump on it.

Ends With Result 1 if the string ends with the specified string.

Environment Map Sets the environment map (on an infinite sphere) and returns its color.

Euler to Quaternion Builds a quaternion with the given euler rotation.

Exponential Computes the exponential function of the argument.

Extract Local Transform Computes a local transform for a KineFX point using its and its parent’s world transforms.

Extract Transform Extracts the translation, rotation, scale or shear component of a 4×4 transform matrix.

Fake Caustics Outputs and opacity value which can be used to approximate caustic lighting effects.

Fast Shadow Sends a ray from the position P along the direction specified by the direction D.

Field Name Provides a fallback value for a field/attribute if the field does not exist or the given field name is an empty string.

Field Parameter Provides a fallback value for a field/attribute if the field does not exist or the given field name is an empty string.

Filter Point Transforms Find a point in an array and return the transforms in the corresponding arrays.

Filter Pulse Train Filters the input.

Filter Shadow Sends a ray from the position P along the direction specified by the direction D, a…

Filter Step Computes the anti-aliased weight of the step function.

Filter Width This function returns the square root of the area of a 3D input or the length of the derivative of a float input, such as s or t.

Find Point Transform Find a point on a given geometry and return its transforms.

Fit Range Takes the value in the source range and shifts it to the corresponding value in the destination range.

Fit Range (Unclamped) Takes the value in the source range and shifts it to the corresponding value in the destination range.

Float to Integer Converts a float value to an integer value.

Float to Matrix Converts sixteen floating-point values to a 4×4 matrix value.

Float to Matrix2 Converts four floating-point values to a matrix2 value.

Float to Matrix3 Converts nine floating-point values to a matrix3 value.

Float to Vector Converts three floating-point values to a vector value.

Float to Vector2 Converts two floating-point values to a vector2 value.

Float to Vector4 Converts four floating-point values to a vector4 value.

Floor Returns the largest integer less than or equal to the argument.

Flow Noise Generates 1D and 3D Perlin Flow Noise from 3D and 4D data.

For Each Transform Perform the same operation on an array of transforms.

Fraction Computes the fractional component of the argument.

Fresnel Computes the Fresnel reflection/refraction contributions given a normalized incident ray, a normalized surface normal, and an index of refraction.

From NDC Transforms a position from normal device coordinates to the coordinates in the appropriate space.

From Polar Converts polar coordinates to cartesian coordinates.

Front Face Returns the front facing normal of a surface, given a surface normal (N) and an incident ray (I).

Fur Guide Global Variables Provides outputs representing commonly used input variables of fur guide shader network.

Fur Guide Output Variables and Parameters Provides inputs representing the output variables of a fur guide shader network.

Fur Procedural Creates a set of hair-like curves across a surface at render time.

Fur Skin Global Variables Provides outputs representing commonly used input variables of fur skin shader network.

Fur Skin Output Variables and Parameters Provides inputs representing the output variables of a fur skin shader network.

Furrows Displaces the surface along the surface normal by an amount equal to the value of an anti-aliased cosine wave.

Fuzzy And Performs a fuzzy and operation between its inputs and returns a value between 0 and 1.

Fuzzy Defuzz Performs a defuzzify operation between its input fuzzy sets and returns a crisp value.

Fuzzy Inference Performs a fuzzy inference operation over each input to determine the truth of the fuzzy set defined on this node.

Fuzzy Input Performs a fuzzify operation that calculates a fuzzy value given a membership function and an input crisp value.

Fuzzy Not This operator performs a fuzzy not operation on an integer or float value.

Fuzzy Obstacle Sense Detects obstacles in an agent’s field of view.

Fuzzy Or Performs a fuzzy or operation between its inputs and returns a value between 0 and 1.

Gather Loop Sends rays into the scene and contains a subnetwork of VOPs to operate on the information gathered from the shaders of surfaces hit by the rays.

Gaussian Random Generates a random number fitting a Gaussian distribution.

Gaussian Random UV Generates a random number fitting a Gaussian distribution.

General Fresnel Computes the Fresnel reflection/refraction contributions and vectors for objects with or without depth.

Generic Shader Represents a shader.

Geometry VOP Global Parameters Provides outputs that represent all the global variables for the Attribute VOP network types.

Geometry VOP Output Variables Simple output variable for Geometry VOP Networks.

Get BSDF Albedo Compute the reflectivity of a bsdf.

Get CHOP Attribute Returns a CHOP attribute value in one of the 4 input CHOPs connected to the Channel VOP.

Get Channel Transform Returns a transform value built from 9 channels from one of the 4 input CHOPs connected to the Channel VOP.

Get Channel Value Returns a sample value in one of the 4 input CHOPs connected to the Channel VOP.

Get Channel Value by Name Returns a sample value in one of the 4 input CHOPs connected to the Channel VOP.

Get Descendant Transforms Traverse the hierarchy from a given point and return their transforms.

Get Dictionary Element Gets a specified value from dictionary.

Get Element Gets a specified element from array.

Get FBIK Attributes Retrieve configuration values for the Physical Full-Body IK solver from point attributes.

Get Full Body COM Return the computed center-of-mass for the given KineFX geometry.

Get Joint Chain Axes Computes a set of orthogonal axes centered at a KineFX joint.

Get Layer Export Obtains a value of the export variable added to the Shader Layer struct.

Get Object Transform Gets the transform matrix of a named object in camera (current) space.

Get Parent Finds the parent of a joint within a KineFX skeleton.

Get Parent Transform Gets the transformation of a joint’s parent within a KineFX skeleton.

Get Point Transform Returns a point transform for a given point index.

Get Point Transforms Returns arrays of point transforms given an array of point IDs.

Get a CHOP Channel Value Evaluates a CHOP channel and return its value.

Gingham Checks Generates anti-aliased gingham checks similar to a tablecloth pattern.

Global Variables Provides outputs that represent all the global variables for the current VOP network type.

Gradient 3D Returns the gradient of a single channel 3D texture image at a specified position within that image.

HSV to RGB Converts HSV color space to RGB color space.

Hair Normal Generates a normal vector which always faces the camera, parallel to the incidence vector.

Hair Shader A powerful, highly flexible, general model for hair/fur shading.

Has Input Returns 1 if the specified input (0-3) is connected.

Has Key Returns if a dictionary has a key.

High-Low Noise Computes a mix of high and low frequency, anti-aliased noise with a wide range of applications.

Houdini Engine Procedural: Curve Generate Cooks a SOP asset for each point in the source geometry and instances the generated curves onto the point.

Houdini Engine Procedural: Point Generate Cooks a SOP asset for each point in the source geometry and instances the generated points onto the point.

Hue Shift Uses the shift value to move the hue of the input color along the color wheel by the amount influenced by the amplitude.

IK Solver Positions and orients points from a root position, end effector position target, and twist position using KineFX Inverse Kinematics.

If Connected Passes through the value of the first input if the first input is ultimately connected.

Illuminance Loop Only available in Surface VOP networks.

Image 3D Iso-Texture Procedural This procedural will generate an iso-surface from a 3D texture image (.i3d file).

Image 3D Volume Procedural This procedural will generate a volume from a 3D texture image (.i3d file).

Import Attribute Imports attribute data from the OP connected to the given input.

Import Displacement Variable Imports the value of the specified variable from a displacement shader and stores it in var.

Import Light Variable Imports the value of the specified variable from a light shader and stores it in var.

Import Properties from OpenColorIO Imports a color space property from Open Color IO.

Import Ray Variable Imports the value of the specified variable sent from a trace() function and stores it in var.

Import Surface Variable Imports the value of the specified variable from a surface shader and stores it in var.

In Group Returns 1 if the point or primitive is in the group specified by the string.

Indirect Lighting Internal VOP used to compute indirect lighting.

Inline Code Write VEX code that is put directly into your shader or operator definition.

Insert Inserts an item, array, or string into an array or string.

Instance with Hscript Procedural Runs hscript for each point in the source geometry and instances the generated geometry to the point.

Integer to Float Converts an integer value to a float value.

Intersect Computes the intersection of a ray with geometry.

Intersect All Computes all the intersections of a ray with geometry.

Invert If given a 3×3 or 4×4 matrix, this operator computes its inverse (or just returns the input matrix if it detects singularity).

Irradiance Computes the irradiance (the global illumination) at the point P with the normal N.

Is Alphabetic Result 1 if all the characters in the string are alphabetic.

Is Connected Outputs 1 if the input is ultimately connected, otherwise it outputs 0.

Is Digit Result 1 if all the characters in the string are numeric.

Is Finite Returns 1 if the number is a normal number, ie, not infinite or NAN.

Is Fog Ray Returns 1 if the shader is being evaluated from within a fog shader.

Is Front Face Returns true if the normal of the surface is forward facing, and false if it isn’t.

Is NAN Returns 1 if the number is not a number.

Is Shadow Ray Returns 1 if the shader is being evaluated for shadow rays.

Join Strings Concatenate all the strings of an array inserting a common spacer.

Joint Angle Gets the angle at the given joint in a KineFX skeleton.

Karma Hair A physically-based hair and fur material.

Lambert Generates a color using the Lambert diffuse lighting model calculation.

Layer Composite Combines two layers using standard compositing operations.

Layer Mix Outputs a mix of the two input layers, blended using the alpha value.

Layer Pack Creates a Layer from individual shading components.

Layer Unpack Unpacks the individual shading components from a layer.

Length Computes the length of an array

Length Computes the length of a 3D or 4D vector.

Lens Bokeh A VOP that can generate different kinds of bokeh.

Lens Chromatic Aberration A VOP that can generates the tint and index of refraction for chromatic aberration effects.

Lens Coordinates A VOP that creates the jittered coordinates for Karma lens shaders.

Lens Distort A VOP that generates the offsets required to distort a Karma lens shader.

Lens Parameters A VOP that generates the Karma lens shader inputs.

Lens Rolling Shutter A VOP that generates a time offset to simulate rolling shutter in digital lenses.

Lens Shutter Curve A VOP that manipulates the time distribution of lens shutters.

Lighting Model Performs a lighting model calculation to generate a color.

Limits Selectively clamps values to a minimum and/or maximum value.

Logarithm Computes the natural logarithm function of the argument.

Look At Computes a 3×3 rotation matrix to orient the z-axis along the vector (to - from) under the transformation.

Look At Constraint Applies a KineFX Look At constraint to a transform.

Luminance Computes the luminance of the RGB color specified by the input parameter.

Make Instance Transform Builds a general 4×4 transform matrix derived from the standard copy/instance attributes

Make Space Transform Returns the transformation matrix to transform from a transform space such as an object’s transform space to another space, such as world space.

Make Transform Builds a general 4×4 transform matrix.

Mandelbrot Set Generates a Mandelbrot pattern.

Map Point Creates a dictionary that maps one KineFX point to another.

MatCap Shader A Material Capture shader.

Material shader builder A higher-level shader that can contain one or more sub-shaders, such as surface shaders, displacement shaders, and rendering properties.

Matrix to Float Unpacks a 4×4 matrix into its sixteen components.

Matrix to Vector4 Unpacks a 4×4 matrix into its rows.

Matrix2 to Float Unpacks a 2×2 matrix2 into its four components.

Matrix2 to Matrix3 Converts a 2×2 matrix to a 3×3 matrix.

Matrix2 to Matrix4 Converts a 2×2 matrix to a 4×4 matrix.

Matrix2 to Vector2 Unpacks a 2×2 matrix into its rows.

Matrix3 to Float Unpacks a 3×3 matrix3 into its nine components.

Matrix3 to Matrix2 Converts a 3×3 matrix to a 2×2 matrix.

Matrix3 to Quaternion Converts a matrix3, representing a rotation, to a quaternion representing the same rotation.

Matrix3 to Vector Unpacks a 3×3 matrix into its rows.

Matrix4 to Matrix2 Converts a 4×4 matrix to a 2×2 matrix.

Matte Implements a matte shader that occludes geometry behind the surface being rendered.

Max Vector Component Computes the maximum value of a vector argument.

Maximum Outputs the maximum value from its inputs.

Meta-Loop Import Takes a handle generated by the Meta-Loop Start operator and will import attributes…

Meta-Loop Next Takes a handle generated by the Meta-Loop Start operator and will iterate to the …

Meta-Loop Start Opens a geometry file and initializes the handle to iterate through all metaballs at the position specified.

Metaball Attribute Returns the value of the given point attribute at the specified position in the metaball field.

Metaball Density Returns the density of the metaball field at the specified position.

Metaball Space Transforms the specified position into the local space of the metaball.

Metaball Weight Returns the metaweight of the geometry at a given position.

Metadata Returns true if the specified metadata exists.

Metadata Returns metadata from one of the 4 input COPs connected to the VEX COP.

Method Represents a method inside a class-based shader.

Method Call Invokes a given method on a given struct or co-shader object.

Method Input Represents a method argument list inside a class-based shader.

Method Subnet Represents a method inside a class-based shader.

Min Vector Component Computes the minimum value of a vector argument.

Minimum Outputs the minimum value from its inputs.

Minimum Position Finds closest position on a primitive in a given geometry file.

Mix Computes a blend (or a mix) of its input values using linear interpolation.

Modulo Computes the modulo of two values.

MtlX AOV Output shading signals to AOVs

MtlX Absorption Vdf Constructs a VDF for pure light absorption.

MtlX Anisotropic Vdf Constructs a VDF scattering light for a participating medium.

MtlX Blackbody Returns the radiant emittance of a blackbody radiator with the given temperature.

MtlX Burley Diffuse Bsdf A BSDF node for Burley diffuse reflections.

MtlX Cellnoise2D 2D cellular noise

MtlX Conductor Bsdf A reflection BSDF node based on a microfacet model and a Fresnel curve for conductors/metals.

MtlX Contrast Increase or decrease contrast of incoming float/color values using a linear slope multiplier.

MtlX Dielectric Bsdf A reflection/transmission BSDF node based on a microfacet model and a Fresnel curve for dielectrics.

MtlX Displacement A constructor node for the displacement shader.

MtlX Generalized Schlick Bsdf A reflection/transmission BSDF node based on a microfacet model and a generalized Schlick Fresnel curve.

MtlX Hsvadjust Adjust the hue, saturation and value of a color.

MtlX Image Samples data from a single image, or from a layer within a multi-layer image.

MtlX Luminance Output a grayscale luminance of a color.

MtlX Measured Edf Constructs an EDF emitting light according to a measured IES light profile.

MtlX Place2D Transform incoming UV texture coordinates for 2D texture placement.

MtlX Rotate2D Rotate a vector2 value about the origin in 2D.

MtlX Saturate Adjust the saturation of a color.

MtlX Sheen Bsdf A microfacet BSDF for the back-scattering properties of cloth-like materials.

MtlX Subsurface BSDF A BSDF for true subsurface scattering.

MtlX Surface Material Constructs a surface shader describing light scattering and emission for closed 'thick' objects.

MtlX Thin Film Bsdf Adds an iridescent thin film layer over a microfacet base BSDF.

MtlX Thin Surface A constructor node for two-sided objects.

MtlX Tiled Image Samples data from a single image, with provisions for tiling and offsetting the image across uv space.

MtlX Translucent Bsdf A BSDF node for pure diffuse transmission.

MtlX USD Preview Surface MaterialX flavor of USD Preview Surface shader

MtlX USD Primvar Reader MaterialX flavor of USD Primvar Reader

MtlX USD Transform 2D MaterialX flavor of USD Transform 2D shader

MtlX USD UV Texture MaterialX flavor of USD UV Texture shader

MtlX Uniform Edf An EDF node for uniform emission.

MtlX Volume A constructor node for the volume shader type.

Multiply Outputs the product of its inputs.

Multiply Add Constant Will take the input value, add the pre-add amount, multiply by the constant multiplier, then add the post-add amount.

Multiply Constant Multiplies the incoming value by a constant.

Near Point Finds closest point in a given geometry file.

Negate Negates the incoming integer, float, vector or vector4 value.

Neighbor Count File Count the number of connected points from a given point in a given geometry file (or op:path)

Neighbor File Finds the nth neighbouring point for a given point in a given geometry file.

Neighbors Retrieves an array of indices to the points connected to the given point.

Normal Clamp Clamp shading normals to prevent bad reflection directions

Normal Falloff Generates a falloff value based on the relationship between the normal and incident vectors.

Normalize Normalizes a vector.

Not This operator performs a logical not operation on an integer value, returning 1 if the input is zero, and 0 if the input is non-zero.

Null Passes the inputs to the output with an optional name change.

OCIO Color Transform Transforms color spaces using Open Color IO.

Occlusion Computes ambient occlusion at the point P with the normal N.

Ocean Sample Layers Sample ocean values from layered ocean spectra at the specified position and time.

Offset Transform Offsets a KineFX transformation matrix by the given transform.

OpenSubdiv Face Count Returns the number of coarse faces in the subdivision hull

OpenSubdiv First Patch Returns the patch of the first patch for a given face in the subdivision hull.

OpenSubdiv Limit Surface Evaluates a point attribute on the limit of a subdivision surface.

OpenSubdiv Lookup Face Outputs the Houdini face and UV coordinates corresponding to the given coordinates on an OSD patch.

OpenSubdiv Lookup Patch Outputs the OSD patch and UV coordinates corresponding to the given coordinates on a Houdini polygon face.

OpenSubdiv Patch Count Returns the number of patches in the subdivision hull

Or This operator performs a logical or operation between its inputs and returns 1 or 0 .

Oren-Nayar Generates a color using the Oren-Nayar diffuse lighting model calculation.

Orient Reorients a vector representing a direction by multiplying it by a 4×4 transform matrix.

Oscillations Returns an anti-aliased cosine or sine wave.

Outer Product Computes the outer product of a pair of vectors.

Output Variables and Parameters Provides inputs representing the writable output variables of the shader network.

PBR Emission Makes a shaded surface emissive.

PBR Hair Primary Reflection Produce a hair BSDF.

PBR Hair Secondary Reflection Produce a hair BSDF.

PBR Hair Transmission Produce a hair BSDF.

PBR Lighting Evaluate Lighting Using PBR.

PBR Non-Metallic Computes reflections and refractions for dielectric (non-metallic) materials.

PBR SSS Creates an approximate SSS BSDF.

PBR Single Scatter Creates a Single Subsurface Scatter BSDF.

Parameter Represents a user-controllable parameter.

Parent Blend Blends between KineFX transforms with an offset computed from the given bind transforms.

Parent Constraint Constrains a KineFX point’s parent to a new world transform.

Periodic Noise Generates 1D and 3D Perlin noise from 1D, 3D and 4D data.

Periodic Worley Noise Computes 1D, 3D, and 4D tileable Worley noise, which is synonymous with cell noise.

Physical Lens A pre-made lens shader implementation with controls for most common lens shader effects, such as bokeh, chromatic aberrations, and tilt/shift.

Physical Lens Core The stripped down version of the physical lens.

Physical SSS Outputs surface color based on a physically-based subsurface scattering model. This node an do physically correct single scattering and/or multiple scattering.

Physically Based Diffuse Produce a normalized diffuse bsdf.

Pixel Area Returns the area of the current pixel after being transformed to the new UV coordinate uvpos.

Pixel Derivative Returns U and V derivatives of the current pixel.

Plane Clip Clips the line segment defined by p1 and p2 against the 3D plane defined by the following equation: plane.

Plane Count Returns the number of planes in the input.

Plane Exists Returns the name of the plane with the index plane_index in input input_index.

Plane Index Returns the index of the plane with the name plane_index in input input_index.

Plane Name Returns the name of the plane with the index plane_index in input input_index.

Plane Size Returns the number of components in the plane with the index plane_index in input input_index.

Point Bounding Box Returns two vectors representing the minimum and maximum corners of the bounding box for the specified geometry.

Point Cloud Close This node closes a point cloud handle opened by pcopen.

Point Cloud Export This node exports point data while inside a pcunshaded loop.

Point Cloud Farthest This node finds the farthest query point produced by pcopen.

Point Cloud Filter This node filters the points queried by pcopen.

Point Cloud Find Returns a list of closest points from a file

Point Cloud Find Radius Returns a list of closest points from a file taking into account their radii.

Point Cloud Import This node imports point data while inside a pciterate or pcunshaded loop.

Point Cloud Import by Index This node imports point data from a pcopen.

Point Cloud Iterate This node advances to the next iteration point returned by pcopen.

Point Cloud Num Found This node returns the number of points found by pcopen.

Point Cloud Open This node opens a point cloud file and searches for points around a source position.

Point Cloud Unshaded This node advances to the next unshaded iteration point returned by pcopen.

Point Cloud Write This function writes data for the current shading point out to a point cloud file.

Point Count Returns the number of points for all primitives in the given geometry.

Point In Group Returns 1 if the point specified by the point number is in the group specified by the string.

Point Instance Procedural The underlying procedural when using Fast Point Instancing with the instance render parameters.

Point Loop Only available in Image3D VOP networks.

Point Replicate The Point Replicate Procedural takes a number of input points and multiplies them, and processes the result using a CVEX script.

Pop Removes the last element of an array and returns it.

Pose Difference Compute the difference between point transforms on two SOP skeletons.

Power Raises the first argument to the power of the second argument.

Primitive Attribute Evaluates an attribute for a given primitive at the specified uv parametric location.

Primitive Intrinsic Evaluates an intrinsic on a given primitive.

Primitive Normal Returns the normal of a primitive (defined by its number) at the given uv parametric location.

Principled Shader An artist-friendly shader that can model a large number of materials realistically.

Print Generate a formatted text string.

Promote Layer Exports Promotes the export variables from the Shader Layer struct to the parent shader

Pyro Blackbody Converts a temperature value into color (chroma) and intensity according to the blackbody radiation model.

Pyro Color Correct Provides color correction functions.

Pyro Color Model Provides constant, artistic, and physically correct (blackbody) tint as well as color correction functions.

Pyro Color Volume Provides functions for editing color fields by conditioning the field values, adding noise, filtering, and color correction.

Pyro Density Volume Provides functions for editing fields such as density by conditioning the field values, adding noise, and filtering.

Pyro Shader Core Provides the core functionality needed to build a high-quality volumetric shader.

Quaternion Takes an angle and an axis and constructs the quaternion representing the rotation about that axis.

Quaternion Distance Computes distance between quaternions in radians.

Quaternion Invert Takes an quaternion inverts it..

Quaternion Multiply Performs a quaternion multiplication with its two inputs.

Quaternion to Matrix3 Converts a vector4, representing a quaternion, to a matrix3 value, representing the same rotation.

RGB to HSV Converts RGB color space to HSV color space.

RSL Gather Loop Sends rays into the scene and contains a subnetwork of VOPs to operate on the information gathered from the shaders of surfaces hit by the rays.

Rainbow Generates a non-repeating rainbow color ramp by modulating the hue over the range of the parametric coordinate s and using the given saturation and value to compute the HSV color.

Ramp Filter Adds anti-aliased analytical filtering to the output of a Ramp Parameter VOP.

Ramp Parameter Represents a user-editable ramp parameter.

Ramps Generates repeating filtered ramps.

Random Generates a random number based on the position in one, three, or four dimensions.

Random Binary Random Jitter Generates a random number in a BRJ sequence.

Random Sobol Generates a random number in a Sobol sequence.

Ray Bounce Weight Returns the amount that the current bounce level will contribute to the final pixel color.

Ray Hit This operator sends a ray from the position P along the direction specified by the direction D, and returns the distance to the object intersected or a negative number if not object found.

Ray Trace Sends a ray starting at origin P and in the direction specified by the normalized vector D.

Realistic Shoulder Propagates rotation from the arm to the clavicle point in a KineFX skeleton.

Reflect Returns the vector representing the reflection of the direction against the normal vector.

Reflected Light Computes the amount of reflected light which hits the surface.

Refract Computes the refraction ray given an incoming direction, the normalized normal and an index of refraction.

Refracted Light Sends a ray starting at origin P and in the direction specified by the normalized vector I.

Regex Find Finds the given regular expression in the string.

Regex Findall Finds all instances of the given regular expression in the string.

Regex Match Result 1 if the entire input string matches the expression.

Regex Replace Replaces instances of find_regex with replace_regex.

Regex Split Splits the given string based on regex match.

Relative to Bounding Box Returns the relative position of the point given with respect to the bounding box of the specified geometry.

Relative to Point Bounding Box Returns the relative position of the point given with respect to the bounding box of the specified geometry.

Remove Index Removes an item at the given index from an array.

Remove Key Removes an item at the given key from a dictionary.

Remove Point Removes points from the geometry.

Remove Value Removes an item from an array.

Render State Gets state information from the renderer.

Reorder Reorders items in an array or string.

Report Error Optionally report a custom VEX error or warning.

Reshape Value Modulates input value using a variety of methods.

Resolution Returns the pixel resolution of an input.

Resolve Mapping Attribute Resolves a mapping dictionary attribute to a KineFX point number.

Rest Position Checks if the geometry attribute rest is bound and, if so, uses it as the rest position for shading.

Return Generates a return statement inside a method or a function defined by the parent subnet.

Reverse Adds an item to an array or string.

Reverse Foot Rotates the foot around custom pivots specific to a reverse foot KineFX set-up.

Rings Generates repeating filtered rings.

Ripples Generates repeating ripples.

Rotate Applies a rotation by 'angle' radians to the given 3×3 or 4×4 matrix.

Rotate by Quaternion Rotates a vector by a quaternion.

Round to Integer Rounds the argument to the closest integer.

Rounded Edge Blends the normals between faces within specified radius.

Rounded Hexes Generates repeating filtered rounded hexagons.

Rounded Stars Generates repeating filtered rounded five-pointed stars.

Run External Program Procedural This procedural will run an external application in order to generate geometry at render time.

SSS Component Adds energy conservation functionality and additional controls to the Physical SSS VOP.

Sample Sphere Samples the interior or surface of the unit circle, sphere, or hypersphere, within a max angle of a direction.

Scale Scales a 3×3 or 4×4 matrix by 'amount' units along the x,y, and z axes.

Scales Generates a scale-like pattern and returns the displaced position, normal, and displacement amount.

Sensor Panorama Color Requests the rendered color from a specified direction

Sensor Panorama Cone Returns an average direction, color, depth, and strength.

Sensor Panorama Create Renders the surrounding environment

Sensor Panorama Depth Requests the rendered depth from a specified direction

Sensor Panorama Save Saves the rendered panorama to a specified output file

Sensor Save Saves sensor data to image files.

Set Agent Clip Names Sets the current animation clips for an agent primitive.

Set Agent Clip Times Sets the current times for an agent primitive’s animation clips.

Set Agent Clip Weights Sets the blend weights for an agent primitive’s animation clips.

Set Agent Layer Sets the current layers or collision layers of an agent primitive.

Set Agent Transforms Overrides the transforms of an agent primitive.

Set CHOP Attribute Sets a CHOP attribute value.

Set Channel Tranform Sets a transform value when evaluating a Channel VOP in Tranlate/Rotate/Scale mode.

Set Channel Value Sets a channel value when evaluating a Channel VOP in Channel/Sample modes.

Set Dictionary Element Sets the value at the specified key.

Set Element Sets the element at the specified index.

Set Layer Component Sets a layer’s components to new values.

Set Layer Export Adds layer exports to the Shader Layer struct

Set Matrix Component Assigns a value to one of the matrix’s components.

Set Matrix2 Component Assigns a value to one of the matrix2's components.

Set Matrix3 Component Assigns a value to one of the matrix3's components.

Set Point Transform Sets one point transform at a given point ID.

Set Point Transforms Sets arrays of point transforms at an array of point IDs.

Set Vector Component Assigns a value to one of the vector’s components.

Set Vector2 Component Assigns a value to one of the vector2's components.

Set Vector4 Component Assigns a value to one of the vector4's components.

Shader Output Export Variables Represents export parameters in a shader call.

Shader Output Global Variables Represents global variables that are bound as output parameters in a shader call.

Shading Area Computes the shading area of the given variable.

Shading Derivative Computes the derivative of a given variable with respect to the s or t parametric coordinate.

Shading Layer Parameter Creates a parameter to appear in the signature of the VEX function defined by the VOP network (VOPNET).

Shading Normal Computes the normal at the location specified by the P position.

Shadow This shader calls the shadow shader inside an illuminance loop.

Shadow Map Shadow Map treats the depth map as if the image were rendered from a light source.

Shadow Matte Implements a shadowmatte shader that occludes geometry behind the surface being rendered.

Sign Returns -1 if the input is less than 0, otherwise it returns 1.

Sine Performs a sine function.

Skin Shader Core A skin shader with three levels of subsurface scattering.

Slice Slices a sub-string or sub-array of a string or array.

Smooth Computes a number between zero and one.

Smooth Rotation Returns the closest equivalent Euler rotations to a reference rotation.

Snippet Runs a VEX snippet to modify the incoming values.

Soft Clip Increases or decreases contrast for values at the top of the input range.

Soft Dots Generates repeating soft dots.

Sort Returns the array sorted in increasing order.

Specular Generates a color using the selected specular lighting model calculation.

Specular Sheen Generates a color using a specular lighting model with a Fresnel falloff calculation.

Spherical Linear Interp Computes a spherical linear interpolation between its two quaternion inputs, and outputs the intermediate quaternion.

Splatter Generates a splatter pattern and returns the splatter amount.

Spline Computes either a Catmull-Rom (Cardinal) spline or a Linear spline between the specified key points, given an interpolant (u) in the domain of the spline.

Split String Splits a string into tokens.

Sprites Procedural This procedural will render points as sprites.

Square Root Computes the square root of the argument.

Starts With Result 1 if the string starts with the specified string.

Stash Transform Stashes a KineFX transform matrix as a constant.

String Length Returns the length of the string.

String to Character Converts an UTF8 string into a codepoint.

Strip Strips leading and trailing whitespace from a string.

Stripes Generates repeating filtered stripes.

Struct Creates, modifies, or de-structures an instance of a structured datatype.

Struct Pack Bundles input values into an instance of an ad-hoc struct.

Struct Unpack Extracts one or more values from a struct by member name.

Sub Network Contains other VOP operators.

Subnet Connector Represents an input or an output (or both) of the parent VOP subnet.

Subnet Input Allows the connection of operators outside a subnet to operators inside the subnet.

Subnet Output Allows the connection of operators inside a subnet to operators outside the subnet.

Subtract Outputs the result of subtracting all its inputs.

Subtract Constant Subtracts the specified constant value from the incoming integer, float, vector or vector4 value.

Surface Color Generates a basic color with a choice of tinting with the point color and/or a color map.

Surface Distance Finds the shortest distance between a point and a source point group.

Switch Switches between network branches based on the value of an input.

Switch Lighting BSDF Use a different bsdf for direct or indirect lighting.

Swizzle Vector Rearranges components of a vector.

Swizzle Vector2 Rearranges components of a vector2.

Swizzle Vector4 Rearranges components of a vector4.

Tangent Performs a tangent function.

Tangent Normal Transform an input normal to UV/tangent space

Tangent Normal Remap Transform an input normal from UV/tangent to current space

Tangent Normals Exports shader normals as a render plane.

Tetrahedron Adjacent Returns primitive number of an adjacent tetrahedron.

Tetrahedron Adjacent Returns vertex indices of each face of a tetrahedron.

Texture Computes a filtered sample of the texture map specified and returns an RGB or RGBA color.

Texture 3D Returns the value of a 3D image at a specified position within that image.

Texture 3D Box Queries the 3D texture map specified and returns the bounding box information for the given channel in the min and max corner vectors.

Thin Film Fresnel Computes the thin film reflection and refraction contributions given a normalized incident ray, a normalized surface normal, and an index of refraction.

Tiled Boxes Generates staggered rectangular tiles.

Tiled Hexagons Generates staggered hexagonal tiles.

Timing Returns the frame range and rate of the given input.

Title Case Returns a string that is the titlecase version of the input string.

To Lower Returns a string that is the lower case version of the input string.

To NDC Transforms a position into normal device coordinates.

To Polar Converts cartesian coordinates to polar coordinates.

To Upper Returns a string that is the upper case version of the input string.

Trace Uses the vex gather function to send a ray and return with the reflected or refracted colors.

Transform Transforms a vector to or from an object’s transform space, or one of several other spaces, such as world or camera space.

Transform From Path Constructs a KineFX transform matrix from a position on a path.

Transform From Surface Constructs a KineFX transform matrix from a position on a geometry’s surface.

Translate Translates a 4×4 matrix 'amount' units along the x,y,z and possibly w axes.

Trigonometric Functions Performs a variety of trigonometric functions.

Turbulent Noise Can compute three types of 1D and 3D noise with the ability to compute turbulence with roughness and attenuation.

Two Bone IK Perform a simple two-bone IK solve

Two Sided Generates a two sided surface.

USD Global Variables Provides outputs representing commonly used input variables for processing USD primitive attributes inside an Attribute VOP LOP.

USD Preview Surface USD Preview Surface shader

USD Prim Var Reader USD Prim Var Reader shader

USD Transform 2D Represents a standard USD primitive for transforming texture co-ordinates.

USD UV Texture Represents a standard USD primitive for looking up texture values.

UV Coords Returns texture coordinates or geometric s and t, depending on what is defined.

UV Noise Disturbs the incoming parametric s and t coordinates using anti aliased noise generated from the Surface Position input.

UV Planar Project Computes UV co-ordinates projected along a single axis, derived from the position of an object, and generates a mask relative to the projection axis.

UV Project Assigns texture coordinates based on the specified projection type.

UV Transform Transforms texture coordinates by the inverse of the matrix consisting of the translation, rotation, and scale amounts.

UV Tri-planar Project Projects texture maps along X, Y, and Z axes and blends them together at the seams.

Unified Noise Presents a unified interface and uniform output range for all the noise types available in VEX.

Unified Noise Static Presents a unified interface and uniform output range for all the noise types available in VEX.

VOP Force Global Provides outputs that represent all the global variables for the Force VOP network type.

VOP Force Output Variables Simple output variable for VOP Force Networks.

VOP nodes VOP nodes let you define a program (such as a shader) by connecting nodes together. Houdini then compiles the node network into executable VEX code.

Vector Cast Converts between different vector types.

Vector To Float Unpacks a vector into its three components.

Vector To Quaternion Takes an angle/axis vector and constructs the quaternion representing the rotation about that axis.

Vector To Vector4 Converts a vector to a vector4.

Vector to Matrix3 Converts rows values to a 3×3 matrix value.

Vector to Vector2 Converts a vector to a vector2 and also returns the third component of the vector.

Vector2 To Float Unpacks a vector2 into its two components.

Vector2 To Vector Converts a vector2 to a vector.

Vector2 To Vector4 Converts a pair of vector2s into a vector4.

Vector2 to Matrix2 Converts rows values to a 2×2 matrix value.

Vector4 to Float Unpacks a vector4 into its four components.

Vector4 to Matrix Converts rows values to a 4×4 matrix value.

Vector4 to Vector Converts a vector4 to a vector and also returns the fourth component of the vector4.

Vector4 to Vector2 Converts a vector4 to a pair of vector2s..

Veins Generates an anti-aliased vein pattern that can be used in any VEX context.

Vex Volume Procedural This procedural will generate a volume from a CVEX shader.

Visualize Exports a vis_ prefixed attribute.

Volume Density to Opacity Computes the opacity of a uniform volume given a density.

Volume Gradient Calculates the gradient of a volume primitive stored in a disk file.

Volume Index Gets the value of a voxel from a volume primitive stored in a disk file.

Volume Index To Pos Calculates the position of a voxel in a volume primitive stored in a disk file.

Volume Index Vector Gets the vector value of a voxel from a volume primitive stored in a disk file.

Volume Model A shading model for volume rendering.

Volume Pos To Index Calculates the voxel closest to a voxel of a volume primitive stored in a disk file.

Volume Resolution Gets the resolution of a volume primitive stored in a disk file.

Volume Sample Samples the value of a volume primitive stored in a disk file.

Volume Sample Vector Samples the vector value of a volume primitive stored in a disk file.

Volume VOP Global Parameters Provides outputs that represent all the global variables for the Volume VOP network type.

Volume VOP Output Variables Simple output variable for Volume VOP Networks.

Voronoi Noise Computes 1D, 3D, and 4D Voronoi noise, which is similar to Worley noise but has additional control over jittering.

Wave Vector Computes the wave vector for a given index in a grid of specified size.

Waves Simulates rolling waves with choppiness of various frequencies, and outputs the positional and normal displacements as well as the amount of displacement.

Wire Pattern Returns float between 0 and 1 which defines a wire grid pattern useful for simulating screens or visualizing parametric or texture coordinates.

Worley Noise Computes 1D, 3D, and 4D Worley noise, which is synonymous with cell noise.

XPU Pyro Preview Simplified smoke, fire, and explosions shader for Karma XPU.

XYZ Distance Finds closest position on a primitive in a given geometry file.

Xor Performs a logical xor operation between its inputs.

agentaddclip Add a clip into an agent’s definition.

Design Lighting Distribution Sytem

This section shows example of semi-direct lighting in an interior space.

DESIGN LIGHTING DISTRIBUTION

SEMI-DIRECT LIGHTING

The images in this section show examples of semi-direct lighting in an interior space. The rendered images are generated for electric lighting of varying interior spaces: office, conference room and classroom.

Roll over each lighting distribution technique to observe semi-indirect lighting condition in different interior spaces.