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Describes a parameter tuple (its name, type, etc.). This is base class for all parameter templates.
ParmTemplates are most often used when describing a parameter in a digital
asset definition’s parameter interface or when describing an individual
node’s parameter layout (including its spare parameters). A ParmTemplate
describes a parameter and the type of data it holds, but it does not store the
current value of a parameter; only hou.Parm objects inside
hou.ParmTuple objects actually store parameter values. You can think of
a hou.ParmTuple as an instance of a ParmTemplate. For example,
the "t" parm tuple on geometry objects can be described by a
hou.FloatParmTemplate – it has a label of "Transform", a data type of
hou.parmData.Float, 3 components, a naming scheme of
hou.parmNamingScheme.XYZW, etc. Each geometry object node has a
hou.ParmTuple named "t" that uses this ParmTemplate.
Note that ParmTemplate objects are just data containers, and they have no live relationship with objects in Houdini. For example, a hou.Node object corresponds directly to a node in Houdini, and if the node is renamed in Houdini hou.Node.name will return the new name. ParmTemplates, on the other hand, do not have a live relationship. Creating a ParmTemplate based on a spare parameter or asset definition parameter will simply copy the information into the ParmTemplate object, and modifying the object will not affect the spare parameter/asset parameter.
Note also that ParmTemplate objects are always instances of a subclass of this class, so you cannot construct an instance of this class directly.
To manipulate the parameters of a digital asset, you can retrieve the asset’s current set of ParmTemplates into a hou.ParmTemplateGroup using hou.HDADefinition.parmTemplateGroup. You can then modify the group, adding parameters to it and replacing parameters in it, and save the group back to the asset definition with hou.HDADefinition.setParmTemplateGroup. Similarly, you can change a node’s parameter layout with hou.Node.parmTemplateGroup and hou.Node.setParmTemplateGroup.
You can also ask a hou.ParmTuple for its ParmTemplate in order to find out information about the parameter, such as allowed ranges of values, the label displayed to the user in the parameter pane, the parameter’s popup help, etc.
Methods
| asCode | Return a string containing Python statements that can be executed to recreate the parameter template. To run the string, use Python’s compile, or execfile functions or the exec statement. |
| clone | Return a copy of this parm template. |
| dataType | Return the data type stored in hou.Parm instances inside hou.ParmTuple instances corresponding to this ParmTemplate. |
| disableWhen | Return the “disable when” string for this ParmTemplate. This string contains the rules for when the parameter should be disabled. |
| help | Return the help that Houdini displays when you hover over the parameter label in the parameter pane. |
| hide | Marks this parameter as visible or invisible in the parameter pane. |
| hideLabel | Hide or show the label for this parameter in the parameter pane. |
| isHidden | Return whether this parameter is hidden in the parameter pane. |
| isLabelHidden | Return whether the label for this parameter is hidden in the parameter pane. |
| joinWithNext | This method is deprecated in favor of the joinsWithNext method. |
| joinsWithNext | Return whether this parameter is displayed on the same line as the next parameter in the parameter pane. |
| label | Return the name of the parameter tuple that is displayed in the parameter pane. |
| look | Return the look of this parameter in the parameter pane. For example, a tuple of 3 floats can be displayed as a 3D vector or as an RGB color. |
| name | Return the internal name of the parm template. This is the name that hou.ParmTuple objects created from this parm template will have. |
| namingScheme | Return the naming scheme used to name parameters inside the parm tuple for this ParmTemplate. |
| numComponents | Return the number of values stored inside hou.ParmTuple instances of this ParmTemplate. |
| scriptCallback | Return the contents of the script that Houdini runs when this parameter changes. This script is most commonly used in hou.ButtonParmTemplate objects to respond to the button being pressed. |
| scriptCallbackLanguage | Return the language of the script that Houdini runs when this parameter changes. |
| setDisableWhen | Set the “disable when” string for this ParmTemplate. |
| setHelp | Set the help that Houdini displays when you hover over the parameter label in the parameter pane. |
| setJoinWithNext | Sets whether this parameter is displayed on the same line as the next parameter in the parameter pane. |
| setLabel | Change the name of the label that is displayed in the parameter pane. |
| setLook | Set the look of this parameter to a hou.parmLook enum value. |
| setName | Change the internal name of this parm template. Remember that ParmTemplates just store data, so the name change will not have any effect unless this parm template is later used to modify a parameter layout in Houdini. |
| setNamingScheme | Set the naming scheme used to name parameters inside the parm tuple for this ParmTemplate to a hou.parmNamingScheme enum value. |
| setNumComponents | Set the number of values stored inside hou.ParmTuple instances of this ParmTemplate. |
| setScriptCallback | Set the callback script to the given string. This script runs in response to a parameter change. |
| setScriptCallbackLanguage | Set the script callback language to a hou.scriptLanguage enum value. |
| setTags | Set the dictionary of extra data stored in this parm template. |
| tags | Return a dictionary of extra data stored in the parm template. |
| type | Return the enumerated value identifying the type of this parameter. |
clone(self)→ hou.ParmTemplateReturn a copy of this parm template.
This method can be called on an instance of a ParmTemplate subclass and an instance of the subclass is properly returned.
name(self)→ stringReturn the internal name of the parm template. This is the name that hou.ParmTuple objects created from this parm template will have.
Note that the names of hou.Parm objects inside ParmTuples based off this ParmTemplate are determined by this name, the number of components in this parm template, and the naming scheme. See the namingScheme method for more information.
setName(self, name)Change the internal name of this parm template. Remember that ParmTemplates just store data, so the name change will not have any effect unless this parm template is later used to modify a parameter layout in Houdini.
label(self)→ stringReturn the name of the parameter tuple that is displayed in the parameter pane.
setLabel(self, label)Change the name of the label that is displayed in the parameter pane.
type(self)→ hou.parmTemplateType enum valueReturn the enumerated value identifying the type of this parameter.
Remember that ParmTemplate objects are always instances of a subclass of this class. The following table shows the mapping between hou.parmTemplateType enumeration values and ParmTemplate subclasses:
dataType(self)→ hou.parmData enum valueReturn the data type stored in hou.Parm instances inside hou.ParmTuple instances corresponding to this ParmTemplate.
For example, suppose this parm tuple is a hou.FloatParmTemplate with 3 components. The corresponding hou.ParmTuple will have 3 hou.Parm objects inside it, and each will store a floating point value. In this example, this method would return hou.parmData.Float.
numComponents(self)→ intReturn the number of values stored inside hou.ParmTuple instances of this ParmTemplate.
For example, if this parm template has 3 components, there will be 3 parameter fields displayed in the parameter pane and there will be 3 hou.Parm objects inside a hou.ParmTuple based off this parm template.
setNumComponents(self, num_components)→ intSet the number of values stored inside hou.ParmTuple instances of this ParmTemplate.
Note that some ParmTemplate subclasses only support one component, so calling this method with a value other than 1 may raise a hou.OperationFailed exception. Also, changing the number of components may automatically change the size of the tuple of default values for some ParmTemplate subclasses.
namingScheme(self)→ hou.parmNamingScheme enum valueReturn the naming scheme used to name parameters inside the parm tuple for this ParmTemplate.
For example, if the naming scheme is hou.parmNamingScheme.XYZW and the parm template is named
"foo"and has 3 components, the parameters will be named"foox","fooy", and"fooz". On the other hand, if the naming scheme was hou.parmNamingScheme.Base1, the parameters would be named"foo1","foo2", and"foo3".Note that when the parm template only has 1 component, the parm name is the same as the parm tuple name.
See hou.parmNamingScheme for more information.
setNamingScheme(self, naming_scheme)Set the naming scheme used to name parameters inside the parm tuple for this ParmTemplate to a hou.parmNamingScheme enum value.
See the
namingSchememethod for more information.look(self)→ hou.parmLook enum valueReturn the look of this parameter in the parameter pane. For example, a tuple of 3 floats can be displayed as a 3D vector or as an RGB color.
See hou.parmLook for more information.
setLook(self, look)Set the look of this parameter to a hou.parmLook enum value.
See the
lookmethod for more information.help(self)→strReturn the help that Houdini displays when you hover over the parameter label in the parameter pane.
setHelp(self, help)Set the help that Houdini displays when you hover over the parameter label in the parameter pane.
isHidden(self)→boolReturn whether this parameter is hidden in the parameter pane.
hide(self, on)Marks this parameter as visible or invisible in the parameter pane.
Note that hidden parameters still exist, and can be evaluated, channel-referenced, etc. They simply will not be displayed in the parameter pane.
isLabelHidden(self)→boolReturn whether the label for this parameter is hidden in the parameter pane.
hideLabel(self, on)Hide or show the label for this parameter in the parameter pane.
joinsWithNext(self)→boolReturn whether this parameter is displayed on the same line as the next parameter in the parameter pane.
joinWithNext(self)→boolThis method is deprecated in favor of the joinsWithNext method.
setJoinWithNext(self, on)Sets whether this parameter is displayed on the same line as the next parameter in the parameter pane.
disableWhen(self)→strReturn the “disable when” string for this ParmTemplate. This string contains the rules for when the parameter should be disabled.
See the Disable When section of the Operator Type Properties window help for more information on this string.
setDisableWhen(self, disable_when)Set the “disable when” string for this ParmTemplate.
See the disableWhen method for more information.
tags(self) -> dict of string to stringReturn a dictionary of extra data stored in the parm template.
Houdini uses this dictionary to attach arbitrary data to parm templates. The keys in this dictionary vary depending on the ParmTemplate type and its use.
scriptCallback(self)→strReturn the contents of the script that Houdini runs when this parameter changes. This script is most commonly used in hou.ButtonParmTemplate objects to respond to the button being pressed.
Note that Houdini uses the tags dictionary to store the script callback information.
setScriptCallback(self, script_callback)Set the callback script to the given string. This script runs in response to a parameter change.
See the scriptCallback method for more information.
scriptCallbackLanguage(self)→ hou.scriptLanguage enum valueReturn the language of the script that Houdini runs when this parameter changes.
Note that Houdini uses the tags dictionary to store the script callback information.
See also the scriptCallback method.
setScriptCallbackLanguage(self, script_callback_language)Set the script callback language to a hou.scriptLanguage enum value.
See the scriptCallbackLanguage method for more information.
setTags(self, tags)Set the dictionary of extra data stored in this parm template.
See the tags method for more information.
asCode(self, function_name=None, variable_name=None)→strReturn a string containing Python statements that can be executed to recreate the parameter template. To run the string, use Python’s
compile, orexecfilefunctions or theexecstatement.function_nameIf function_name is specified, then the code returned creates a Python function with the given name. function_name must be a non-zero length string consisting of only alphanumeric and underscore characters. Any invalid characters are internally converted to underscores.
The function returns a reference to the newly created parameter template object.
variable_nameThe name of a Python variable that the result code will assign to. If
None, Houdini uses the variable name"hou_parm_template".Here is an example of saving the output to a file and then loading it back into Houdini:
# Get a reference to the target parameter template. node = hou.node("/obj/geo1") parm_template = node.parm("tx").parmTemplate() # Execute asCode and write the output script to a file. code = parm_template.asCode() source_file = open("create_parm_template.py", "w") source_file.write(code) source_file.close() # Execute the script. The new parameter template will be stored # in the 'hou_parm_template' variable. execfile("create_parm_template.py") # Add a spare parameter to the node using the saved parameter # template. node.addSpareParmTuple(hou_parm_template)
Here is an example of saving the output into a function in a file and then calling it from Houdini:
# Get a reference to the target parameter template. node = hou.node("/obj/geo1") parm_template = node.parm("tx").parmTemplate() # Execute asCode and write the function definition to a file. code = parm_template.asCode(function_name="createParmTemplate") source_file = open("parmtemplatelib.py", "w") source_file.write(code) source_file.close() # Call the function definition. import parmtemplatelib hou_parm_template = parmtemplatelib.createParmTemplate() # Add a spare parameter to the node using the saved parameter # template. node.addSpareParmTuple(hou_parm_template)