Hello @kng_ito,
Thank you for reaching out to us. Modifying the description of a node via NodeData.GetDDescription should only be done when NodeData.GetDEnabling is not sufficient. To hide a parameter, the field c4d.DESC_HIDE must be set to True. Find a simple example below.
Cheers,
Ferdinand
Result:
hide_param.gif
File: pc14487.zip
Code:
// The description defintion of the tag Texample.
CONTAINER Texample
{
NAME Texample;
INCLUDE Texpression;
// The main "Tag" tab of the tag.
GROUP ID_TAGPROPERTIES
{
// The element which is being hidden (or not).
REAL ID_HIDDEN_ELEMENT { MIN 0.0; MAX 100.0; UNIT METER; STEP 0.001; CUSTOMGUI REALSLIDER; }
// The parameter based on which the hidden element is shown or not.
BOOL ID_HIDE_CONDITION {}
}
}
"""Implements a tag which dynamically hides and shows a parameter.
"""
import c4d
import typing
class ExampleTagData(c4d.plugins.TagData):
"""Implements a tag which dynamically hides and shows a parameter.
"""
# The plugin ID for the hook.
ID_PLUGIN: int = 1060794
@classmethod
def Register(cls) -> None:
"""Registers the plugin hook.
"""
if not c4d.plugins.RegisterTagPlugin(
id=cls.ID_PLUGIN,
str="Example Tag",
info=c4d.TAG_EXPRESSION | c4d.TAG_VISIBLE,
g=cls,
description="texample",
icon=c4d.bitmaps.InitResourceBitmap(c4d.Tdisplay)):
print(f"Warning: Failed to register '{cls}' tag plugin.")
def Init(self, node: c4d.GeListNode) -> bool:
"""Called to initialize a tag instance.
Args:
node: The BaseTag instance representing this plugin object.
"""
self.InitAttr(node, float, c4d.ID_HIDDEN_ELEMENT)
self.InitAttr(node, bool, c4d.ID_HIDE_CONDITION)
node[c4d.ID_HIDDEN_ELEMENT] = 50.0
node[c4d.ID_HIDE_CONDITION] = False
return True
def Execute(self, tag: c4d.BaseTag, doc: c4d.documents.BaseDocument, op: c4d.BaseObject,
bt: c4d.threading.BaseThread, priority: int, flags: int) -> int:
"""Called when expressions are evaluated to let a tag modify a scene.
Not used in this case.
"""
return c4d.EXECUTIONRESULT_OK
def GetDDescription(self, node: c4d.GeListNode, description: c4d.Description,
flags: int) -> typing.Union[bool, tuple[bool, int]]:
"""Called by Cinema 4D when the description of a node is being evaluated to let the node
dynamically modify its own description.
"""
# Bail when the description cannot be not fully loaded.
if not description.LoadDescription(node.GetType()):
return False, flags
# Define the ID of the parameter we want to modify and get the ID of the parameter which is
# currently to be evaluated.
paramId: c4d.DescID = c4d.DescID(c4d.DescLevel(c4d.ID_HIDDEN_ELEMENT, c4d.DTYPE_REAL, 0))
evalId: c4d.DescID = description.GetSingleDescID()
# Bail when there is a to be evaluated parameter and our parameter is not part of or equal
# to the evaluated parameter.
if (evalId and not paramId.IsPartOf(evalId)):
return True, flags
# Get the description data container instance (GetParameter>I<) for the parameter we want to
# modify. All changes made to the container will be directly reflected on the node.
paramData: c4d.BaseContainer = description.GetParameterI(paramId)
if paramData is None:
return True, flags
# Set the hidden state of the parameter ID_HIDDEN_ELEMENT based on the value of the
# parameter ID_HIDE_CONDITION.
paramData[c4d.DESC_HIDE] = node[c4d.ID_HIDE_CONDITION]
return True, flags | c4d.DESCFLAGS_DESC_LOADED
if __name__ == "__main__":
ExampleTagData.Register()
