See the network and parameters chapter for more information on HScript expressions. You can also use Python in parameters instead of HScript expressions.
Functions ¶
-
Returns the absolute value of the argument.
-
Returns the full path of a file.
-
Returns the arc-cosine of the argument.
-
Returns the angular velocity required to rotate an object from one orientation to another in a certain period of time.
-
Returns the arc length of a curve between two U positions.
-
Returns the arc length of a curve between two U positions and number of divisions.
-
Returns an argument from a list of HScript-style arguments.
-
Returns the number of arguments in an HScript-style list of arguments.
-
Returns the arc-sine of the argument.
-
Returns the arc-tangent of the argument.
-
Returns the arc-tangent of y/x.
-
Converts a string to a float.
-
Returns a space-separated list of attribute names.
-
Returns bounding box information for a surface node.
-
Channel segment function: Bezier interpolation spline
-
Combines two numbers with bitwise-and.
-
Combines two numbers with bitwise-or.
-
Sets or clears a bit in a number.
-
Returns if a given bit is set.
-
Combines two numbers with bitwise-xor.
-
Returns the angle at the joint between two bone objects.
-
Returns the smallest integer not less than the value passed in.
-
Returns centroid information for a surface node.
-
Returns the value of a parameter.
-
Returns 1 if the specified channel exists, 0 if it doesn’t.
-
Evaluates a channel with a new segment expression.
-
Evaluates a channel with a new segment expression at a given frame.
-
Evaluates a channel with a new segment expression at a given time.
-
Evaluates a parameter at a given frame.
-
return a string containing all of the channels contained in a group.
-
Evaluates a channel within a CHOP at the current time.
-
Evaluates a channel within a CHOP at a given time.
-
Evaluates a channel within a CHOP at a specified sample point.
-
Evaluates a channel within a CHOP at a specified time.
-
Returns the end index of the channels in a CHOP.
-
Evaluates a channel within a CHOP with at a given frame.
-
Evaluates a channel within a CHOP at a given sample point.
-
Returns the length of the channels in a CHOP, in samples.
-
Returns the number of data channels within a CHOP.
-
Returns the names of all the data channels within a CHOP.
-
Returns the sample rate of a CHOP.
-
Returns the start index of a CHOP.
-
Returns the string value of a channel within a CHOP at the current time.
-
Returns the value of a channel within a CHOP at a specified time.
-
Returns the value of a ramp parameter at a specific position.
-
Returns the value of a ramp parameter at a specific position and frame.
-
Returns the value of a ramp parameter at a specific position and time.
-
Evaluates the string value of a parameter at the current time.
-
Evaluates the parameter at the current time as a node path string.
-
Evaluates the parameter at the current time as a node path list string.
-
Returns the raw (unexpanded) expression value of a parameter as a string.
-
Returns the value of a parameter at a specified time.
-
Returns a value clamped between a minimum and maximum.
-
Clamps a vector to always end between a minimum and maximum sphere.
-
Channel segment function: constant value.
-
Returns the value of context option as a floating point value.
-
Returns a cook context option as a string value.
-
Tests if metadata exists on a compositing node.
-
Tests if a plane exists on a compositing node.
-
Returns the number of wires in a cable leading into a COP node’s input port.
-
Checks for presence of data flowing into a COP node’s input port.
-
Returns type information of a COP node’s input port.
-
Returns numeric metadata from a compositing node.
-
Returns string metadata from a compositing node.
-
Returns the number of wires in a cable coming out of a COP node’s output port.
-
Checks for presence of data flowing out of a COP node’s output port.
-
Returns type information of a COP node’s output port.
-
Returns the cosine of the argument.
-
Returns the hyperbolic cosine of the argument.
-
Computes the cross-product of two vectors.
-
Channel segment function: cubic spline.
-
Deprecated: current working container for custom panels.
-
Deprecated: data type of a gadget, for custom panels.
-
Deprecated: adds a menu entry on a custom panel.
-
Deprecated: returns a value from a custom panel.
-
Returns the curvature of the surface at the given UV coordinates.
-
Deprecated: Returns the type of a gadget on a custom panel.
-
Channel segment function: repeats animation from previous frames.
-
Channel segment function: repeats the animation between frames f1 and f2, accumulating the value.
-
Channel segment function: repeats the animation between times t1 and t2, accumulating the value.
-
Channel segment function: repeats animation from previous frames.
-
Decodes a variable name that was previously encoded.
-
Decodes a geometry attribute name that was previously encoded.
-
Decodes a node parameter name that was previously encoded.
-
Converts from radians to degrees.
-
Returns the degree a specified face or hull.
-
Returns the value of a detail attribute.
-
Returns a space-separated list of detail attribute names.
-
Returns the number of components in a detail attribute.
-
Returns the type of a detail attribute.
-
Returns the string value of a detail attribute.
-
Returns a string from a list of strings in a detail attribute.
-
Returns the number of unique strings bound to a detail attribute.
-
Returns components of a string array attribute.
-
Returns the determinant of a matrix.
-
Computes the dihedral matrix between vectors v0 and v1.
-
Returns the distance between two 3D points.
-
Returns a space separated list of all the field names that can be passed to the dopfield function.
-
Returns the full path of the node connected to a dopnetwork.
-
Returns the number of records of a given type in a piece of dynamics data.
-
Returns the value of a field as a float.
-
Returns the name of a DOP field.
-
Returns the value of a DOP field as a string.
-
Returns the type of a DOP field.
-
Returns the current frame of the simulation.
-
Returns the simulation time equivalent of a simulation frame.
-
Returns 1 if a specified DOP group contains a specified object.
-
Returns 1 if a specified DOP group is mutually affecting.
-
returns a string containing a list of all object groups for the current time in a specified DOP Network.
-
Returns 1 if a specified DOP field exists.
-
Returns 1 if a dynamics object has the specified subdata.
-
Returns the list of objects processed by a DOP in the latest timestep.
-
Returns the number of fields in a DOP record type.
-
returns the number of objects in a simulation.
-
Returns the number of records of a given type in a piece of dynamics data.
-
Returns the number of types of record in a piece of dynamics data.
-
Returns the number of subdata items attached to an object or data.
-
Returns all objects matching the an object specification.
-
Tests whether a set of objects has an affector relationship with another object.
-
Returns the list of objects created by a particular DOP node.
-
Returns the value of a DOP field as a float.
-
Returns the value of a DOP field as a string.
-
Returns the name of a record in DOPs data given its index.
-
Script solver support function.
-
Script solver support function.
-
Script solver support function.
-
Script solver support function.
-
Script solver support function.
-
Script solver support function.
-
returns the simulation frame of a given simulation time.
-
Returns the global time of a given simulation time.
-
Returns the name of a subdata of a given DOP object.
-
Returns the current time of a simulation.
-
Returns a transformation matrix associated with a piece of data.
-
Returns the simulation time equivalent to a given global time.
-
Returns the velocity that a point at a location in simulation space would have if it were attached to a DOP object.
-
Computes the dot product of two vectors.
-
Channel segment function: ease-in and -out.
-
Channel segment function: ease-in.
-
Channel segment function: ease-in with configurable acceleration.
-
Channel segment function: ease-out
-
Channel segment function: ease-out with configurable acceleration.
-
Channel segment function: ease-in and -out with configurable acceleration.
-
Returns the list of edge groups in a surface node.
-
Returns the list of edge groups matching a pattern in a surface node.
-
Fits a value from one range to another.
-
Encodes any string into a valid variable name.
-
Encodes any string into a valid geometry attribute name.
-
Encodes any string into a valid node parameter name.
-
Evaulates a string as an expression returning a float.
-
Evaulates a string as an expression returning a string.
-
Runs a string as an HScript command and returns the command’s output.
-
Runs a string as an HScript command and returns the command and error output.
-
Runs a string as an HScript command and returns any error output.
-
Returns the logarithmic exponentiation of the argument.
-
Explodes a 3×3 or 4×4 matrix into the euler rotations required to rebuild it.
-
Explodes a 3×3 or 4×4 matrix into the euler rotations required to rebuild it.
-
Explodes a 3×3 or 4×4 matrix into the euler rotations required to rebuild it.
-
Searches the Houdini path for a file.
-
Searches the Houdini path for a file or directory.
-
Fits a value from one range to another.
-
Fits a value to the 0-1 range.
-
Fits a number in the 0-1 range.
-
Fits a number to the -1 to 1 range.
-
Returns the largest integer not greater than a number.
-
Returns a string padding a number to a given length with zeros.
-
Returns the fractional part of a floating-point number.
-
Converts a number to a string.
-
Converts a number to a string, with rounding.
-
Returns a string describing the set of elements with a given value for an integer attribute.
-
Returns a string describing the set of elements with a given value for a string attribute.
-
Returns a non-zero value if the specified context option exists.
-
Returns 1 if a specified detail attribute exists.
-
Returns 1 if the active PDG work item has the specified attribute.
-
Returns 1 if a specified point is in a specified group.
-
Returns 1 if a specified point attribute exists.
-
Returns 1 if a specified primitive is in a specified group.
-
Returns 1 if a specified primitive attribute exists.
-
Returns 1 if a specified vertex attribute exists.
-
Converts a hexadecimal argument string into an integer.
-
Converts RGB values to HSV components.
-
Evaluates a CHOP’s input channel at a specific index.
-
Returns the end index of a CHOP’s input.
-
Returns the length of a CHOP’s input, in samples.
-
Evaluates a CHOP’s input channel’s maximum value.
-
Evaluates a CHOP’s input channel’s minimum value.
-
Returns the number of channels in a CHOP’s input.
-
Returns the sample rate of a CHOP’s input.
-
Returns the start index of a CHOP’s input.
-
Creates an identity matrix.
-
Returns the value of the second or third argument depending on the truth of the first argument.
-
Returns the string value of the second or third argument depending on the truth of the first argument.
-
Finds the first occurrence of a pattern in a string.
-
Returns the point number currently being instanced onto.
-
Converts a number to an integer by truncating any fractional part.
-
Converts a number into a hexadecimal string.
-
Inverts a matrix.
-
Queries numeric (floating point) data from an interactive render pane.
-
Queries textual (string) data from an interactive render pane.
-
Returns 1 if a primitive is closed.
-
Returns 1 if a specified point has collided with something.
-
Returns 1 if a specified Houdini environment variable exists.
-
Returns 1 if the parameter is being evaluated as part of a PDG cook, else 0
-
Returns 1 if a specified primitive is a NURBs or Bezier curve or surface.
-
Returns 1 if a specified point is a stuck particle.
-
Returns 1 if a specified Houdini or system environment variable exists.
-
Returns 1 if a specified primitive is wrapped in U.
-
Returns 1 if a specified primitive is wrapped in V.
-
Returns the length of a vector.
-
Channel segment function: linear interpolation.
-
Returns a list of elements with a given value for an integer attribute.
-
Returns a list of elements with a given value for a string attribute.
-
Returns a value that cannot be changed.
-
Returns the natural logarithm of the argument.
-
Returns the base 10 logarithm of the argument.
-
Returns the path of the USD primitive last modified by an input to a LOP node.
-
Returns the paths of the USD primitives last modified by an input to a LOP node.
-
Returns the path of the USD primitive last modified by a LOP node.
-
Returns the paths of the USD primitives last modified by a LOP node.
-
Returns the paths of the parents of the supplied list of USD primitives.
-
Returns the paths at a particular location relative to the supplied list of USD primitives.
-
Trims white sapce from the front of a string.
-
Channel segment function: matches the incoming and outgoing values.
-
Channel segment function: matches the incoming slope.
-
Channel segment function: matches the outgoing slope.
-
Converts a string specification into a matrix.
-
Converts a rotation matrix to a quaternion.
-
Returns the larger of two values.
-
Returns the number of columns in a matrix.
-
Returns the weight of a metaball at a specific location.
-
Returns the smaller of two values.
-
Finds the smallest distance between a point and a primitive.
-
Computes the transformation matrix of a lookat from one vector to another.
-
Computes the transformation matrix of a lookat from one vector to another, with an up vector.
-
Computes the transformation matrix of a lookat from one object to another.
-
Blends the two modular values.
-
Computes the transformation matrix to orient along specific Z and Y axes.
-
Returns the full name of the pane currently under the mouse pointer.
-
Returns the node path of the pane currently under the mouse pointer.
-
Returns the number of rows in a matrix.
-
Returns a matrix with all values set to 0.
-
Finds the point in a geometry nearest to specific 3D coordinates.
-
Generates 3D noise.
-
Returns the components of the surface normal specific UV coordinates.
-
Normalizes a vector.
-
Returns the number of points in a geometry.
-
Returns the number of points in the specified group.
-
Returns the number of primitives in a surface node.
-
Returns the number of primitives in the specified group.
-
Returns the number of unique values for an integer or string attribute in a surface node.
-
Returns the number of vertices in a geometry.
-
Returns the number of vertices in the specified group.
-
Returns the current global kinematic override setting for bone objects.
-
Returns a list of lights matching an object’s light mask.
-
Computes the rotation vector of a lookat from one object to another.
-
Returns an object’s pre-transform matrix.
-
Returns the value of a CHOP’s output at a specific sample index.
-
Queries the current OpenCL device with the provided flag
-
Returns a pseudo-random number between 0 and 1.
-
Returns the full paths of all operators in a bundle.
-
Returns the creator of this node.
-
Returns the numeric suffix of a node name.
-
Returns 1 if the specified node, group, or bundle exists.
-
Returns a list nodes with a particular flag set.
-
Returns the full path of a node.
-
Returns the path of a node relative to another node.
-
Returns the unique ID of a node.
-
Returns the name of the node connected to a given input.
-
Returns the full path of the node connected to a given input.
-
Returns the value associated with a key string on node connection.
-
Returns 1 if Houdini is currently loading a scene file.
-
Returns 1 if Houdini is currently shutting down.
-
Returns a list of lights matching an object’s light mask.
-
Sorts a list of node paths based on node input/outputs order.
-
Returns the name of a node given its path.
-
Returns the number of nodes inside a container node.
-
Returns the maximum number of connected inputs.
-
Returns the alphanumeric prefix of a node name eliminating trailing digits.
-
Returns the number of nodes connected to a node’s output.
-
Returns the name of a node connected a given node’s output.
-
Returns the full path of a node connected a given node’s output.
-
Deprecated: replaced by opinput.
-
Returns the path of the current network.
-
Prints the path of the current network.
-
Returns the relative path from one node to another.
-
Returns a list of the selected nodes.
-
Returns a list of the full paths of selected nodes.
-
Returns a recursive list of the selected nodes.
-
Returns a recursive list of the full paths of selected nodes.
-
Computes the active stream of a node.
-
Returns the full path of a node including any containing subnets.
-
Returns the transformation matrix of an object at the current time.
-
Returns the type of a node.
-
Returns type information about a node.
-
Returns components of an object’s transforms.
-
Returns components of an object’s offset transforms.
-
Returns a string padding a number to a given length with zeros.
-
Deprecated: use stamp instead.
-
Returns 1 if a specified parameter is a string.
-
Returns the value of a PDG work item attrib
-
Returns the value of a PDG work item attrib as a file path
-
Returns the space separated list of file pathss for a PDG work item attribute
-
Returns a space-separated list of attribute names on the active PDG work item.
-
Returns the string value of a PDG work item attribute
-
Returns the number of components in a PDG work item attribute.
-
Returns the type of a PDG work item attribute.
-
Deprecated: replaced by pdgattrib.
-
Deprecated: replaced by pdgattribs.
-
Returns the space separated list of values for a PDG work item attribute
-
Returns a work item input file for the specified file index and tag
-
Returns the number of input files on the active PDG work item
-
Returns the file tag for the input file at the specified index.
-
Returns a space separated string of all work item input files for the specified tag
-
Maps the given path to the local Zone
-
Returns a work item output file for the specified file index and tag
-
Returns the number of output files on the active PDG work item
-
Returns the file tag for the output file at the specified index.
-
Returns a space separated string of all work item output files for the specified tag
-
Returns the color of a pixel in a compositing node.
-
Returns the non-interpolated color of a pixel in a compositing node.
-
Converts an English noun to its plural.
-
Returns the value of a point attribute.
-
Returns a space-separated list of point attribute names.
-
Returns the number of components in a point attribute.
-
Returns the type of a point attribute.
-
Returns the average of an attribute across all points in a geometry.
-
Returns the distance between a point and a primitive.
-
Returns the list of point groups in a surface node.
-
Returns the list of point groups matching a pattern in a surface node.
-
Returns a list of all points in a point group.
-
Lists points that share a minimum number of primitives with a specified point.
-
Returns a list of points that match a specified pattern.
-
Returns the string value of a point attribute.
-
Returns a string from a list of strings in a point attribute.
-
Returns the number of unique strings bound to a point attribute.
-
Returns components of a string array attribute.
-
Raises a number to an exponent.
-
Returns the value of a primitive attribute.
-
Returns a space-separated list of primitive attribute names.
-
Returns the number of components in a primitive attribute.
-
Returns the type of a primitive attribute.
-
Returns the minimum distance and closest points between two primitives.
-
Returns the partial derivatives of a primitive attribute.
-
Returns the list of primitive groups in a surface node.
-
Returns the list of groups matching a pattern in a surface node.
-
Returns a list of all primitives in a surface node.
-
Lists primitives that share a minimum number of points with a specified primitive.
-
Returns the string value of a primitive attribute.
-
Returns a string from a list of strings in a primitive attribute.
-
Returns the number of unique strings bound to a primitive attribute.
-
Returns the value of a primitive attribute at a certain UV location.
-
Returns components of a string array attribute.
-
Prints a message to the console.
-
Similar to ch(), but for render properties, with a default if the property doesn’t exist.
-
Evaluates a render property at a given frame.
-
Evaluates the string value of a render property at the current time.
-
Evaluates a render property at the current time as a node path string.
-
Evaluates the raw (unexpanded) string value of a render property at the current time.
-
Evaluates a render property at a given time.
-
Returns 1 when a value is within a certain range.
-
Evaluates a Python expression, returning a float result.
-
Evaluates a Python expression, returning a string result.
-
Channel segment function: uses quaternions to interpolate.
-
Converts quaternion to a 3×3 rotation matrix.
-
Channel segment function: smoothly interpolates slopes and accelerations.
-
Converts from degrees to radians.
-
Returns a pseudo-random number from 0 to 1.
-
Channel segment function.
-
Converts unit UV to real UV.
-
Returns the relative path of a file.
-
Channel segment function: repeats animation from previous frames.
-
Channel segment function: repeats animation from previous frames.
-
Returns the natural resolution of the image in a compositing node.
-
Converts HSV values to RGB components.
-
Finds the last occurrence of a pattern in a string.
-
Rounds to the nearest integer.
-
Returns a 4×4 rotation matrix from an axis and angle.
-
Returns a 4×4 rotation matrix from an angle and a vector.
-
Rounds a number to the nearest integer.
-
Trims white sapce from the end of a string.
-
Runs a string as an HScript command and returns the command’s output.
-
Runs a string as an HScript command and returns the command and error output.
-
Runs a string as an HScript command and returns any error output.
-
Takes three scaling values and returns a scale matrix.
-
Returns the scale factor converting from MKS units to the Houdini units.
-
Returns the scale factor converting to MKS units from the Houdini units.
-
Lists all seam points in a surface node.
-
Returns 1 if a specified compositing node has an animated sequence.
-
Returns the end frame of a compositing node’s image sequence.
-
Returns the number of frames in a compositing node’s image sequence.
-
Returns the start frame of a compositing node’s image sequence.
-
Returns the shader string generated by a shader.
-
Returns -1, 0, or 1 depending on the sign of the argument.
-
Returns the sine of the argument.
-
Returns the hyperbolic sine of the argument.
-
Takes a value and range and returns a smooth interpolation between 0 and 1.
-
Generates sparse convolution 3D noise.
-
Returns a knot value on a spline curve or surface.
-
Channel segment function: fits a curve to the keyframes.
-
Returns the square root of the argument.
-
Returns a copy stamping floating point value.
-
Returns a copy stamping string value.
-
Compares two strings, ignoring case.
-
Returns 1 if a string matches a pattern, ignoring case.
-
Returns the concatenation of two strings.
-
Compares two strings.
-
Duplicates a string.
-
Strips non-essential characters from the string representation of a matrix or vector.
-
Returns the number of characters in a string.
-
Returns 1 if a string matches a pattern, including case.
-
Replaces substrings with a new string.
-
Returns one component of a string split by some separators.
-
Returns the number of components in a string split by some separators.
-
Generates spatially coherent 3D noise based on sparse convolution.
-
Returns a substring of a string.
-
Returns the length of the 3D curve between two points on a surface.
-
Runs a system command line and returns the output.
-
Runs a system command line and returns the exit status.
-
Runs a system command line and returns the output with no processing.
-
Returns the tangent of the argument.
-
Returns the hyperbolic tangent of the argument.
-
Returns the interpolated color of a point on an on-disk texture map.
-
Returns the non-interpolated color of a point on an on-disk texture map.
-
Returns the all-lowercase version of a string.
-
Returns the all-uppercase version of a string.
-
Takes X, Y, and Z translation values and returns a translation matrix.
-
Transposes a matrix.
-
Trims white sapce from either side of a string.
-
Converts a number to an integer by truncating any fractional part, rounding towards 0.
-
Generates spatially coherent 3D noise.
-
Returns a unique value of an integer attribute.
-
Returns a unique value of a string attribute.
-
Converts real UV to unit UV.
-
Returns the paths of the USD primitives that match a pattern.
-
Returns the distance between parameteric locations on two primitives.
-
Returns the angle between two vectors.
-
Converts a string specification into a vector.
-
Converts three values into a 3-component vector.
-
Converts four values into a 4-component vector.
-
Returns the value of a vertex attribute.
-
Returns a space-separated list of vertex attribute names.
-
Returns the number of components in a vertex attribute.
-
Returns the type of a vertex attribute.
-
Returns the list of vertex groups in a surface node.
-
Returns the list of vertex groups matching a pattern in a surface node.
-
Returns the string value of a vertex attribute.
-
Returns a string from a list of strings in a vertex attribute.
-
Returns the number of unique strings bound to a point attribute.
-
Returns components of a string array attribute.
-
Returns the length of a vector.
-
Channel segment function: matches the incoming and outgoing slopes.
-
Channel segment function: matches the incoming slope.
-
Channel segment function: matches the outgoing slope.
-
Returns the average value of all the voxels in a volume.
-
Returns the gradient of a volume primitive at a specified location.
-
Returns the value of a volume primitive at a specified voxel.
-
Converts volume voxel coordinates to world-space coordinates.
-
Returns the maximum value of all voxels in a volume.
-
Returns the minimum value of all voxels in a volume.
-
Converts world space coordinates to volume voxel coordinates.
-
Returns the resolution of a volume.
-
Returns the value of a volume at a specified position.
-
Returns the approximage diameter of a volume voxel in world space.
-
Returns a vector of an objects' transforms.
-
Takes a viewer name and a viewport number and returns the viewport’s name.
-
Returns a vector of an object’s rotations.
-
Multiplies a vector by a scaling factor.
-
Creates a vector with each component set to the same value.
-
Returns the number of elements in a vector.
-
Returns a vector of an object’s translations.
-
Wraps a value between a minimum and maximum.
-
Returns the distance between a 3D coordinate and a primitive.
