Python Tag how to hide a mogragh object

Dunhou

Hello everyone,

I want to hide an object from a cloner, I test in a python effector and work well , but in a python tag in didn't work anymore . what is wrong with the codes?

Modata Flags .c4d

from typing import Optional
import c4d

doc: c4d.documents.BaseDocument # The document evaluating this tag
op: c4d.BaseTag # The Python scripting tag
flags: int # c4d.EXECUTIONFLAGS
priority: int # c4d.EXECUTIONPRIORITY
tp: Optional[c4d.modules.thinkingparticles.TP_MasterSystem] # Particle system
thread: Optional[c4d.threading.BaseThread] # The thread executing this tag

def main() -> None:
    obj = op.GetObject()
    moData = c4d.modules.mograph.GeGetMoData(obj)
    if moData is None:
        return False

    cnt = moData.GetCount()
    marr = moData.GetArray(c4d.MODATA_MATRIX)
    farr = moData.GetArray(c4d.MODATA_FLAGS)

    #hasField = op[c4d.FIELDS].HasContent()
    #fall = moData.GetFalloffs()

    farr[4] &= ~ (c4d.MOGENFLAG_CLONE_ON)

    moData.SetArray(c4d.MODATA_FLAGS, farr, 0)
    moData.SetArray(c4d.MODATA_MATRIX, marr, 0)

Cheers~
DunHou

Manuel

hi,

I got the feeling it will not work but i need to investigate a lot more. Either you are modifying the MoData too early, and the cloner will erase/initialise them after you modified them, or you are modifying them after the cloner have generated the clones.

That is why we have the effectors to modify the Modata before the cloner have generated the clones.

Is there any reason you want to use a tag instead of an effector?

Cheers,
Manuel

HerrMay

Hi @Dunhou,

for the time being you can modify the clones from a python tag via the help of a MoSelection tag.

Cheers,
Sebastian

from typing import Optional
import c4d

doc: c4d.documents.BaseDocument # The document evaluating this tag
op: c4d.BaseTag # The Python scripting tag
flags: int # c4d.EXECUTIONFLAGS
priority: int # c4d.EXECUTIONPRIORITY
tp: Optional[c4d.modules.thinkingparticles.TP_MasterSystem] # Particle system
thread: Optional[c4d.threading.BaseThread] # The thread executing this tag

def main() -> None:
    """Example showing a workaround on how to modify clones via a python tag.
    To get this working we need a MoSelection tag as a man in the middle to transfer modified data
    from this python tag to a e.g. cloner object.
    """

    moselection = op[c4d.ID_USERDATA,1] # Userdata link filed where you are supposed to drop your MoSelection tag.
    obj = op.GetObject()

    if not obj or not moselection: # Bail if there is no host object or no MoSelection tag.
        return

    baseselect = c4d.modules.mograph.GeGetMoDataSelection(moselection) # Retrieve a c4d.BaseSelect from the MoSelection tag.
    moData = c4d.modules.mograph.GeGetMoData(obj)

    if moData is None:
        return False

    farr = moData.GetArray(c4d.MODATA_FLAGS) # Read the MoData array you want to modify.
    farr[4] &= ~ (c4d.MOGENFLAG_CLONE_ON) # Modify the array to your liking.

    baseselect.SetAll(states=farr) # Set the c4d.BaseSelect from the modified array data.
    c4d.modules.mograph.GeSetMoDataSelection(op=moselection, selection=baseselect) # Write back the c4d.BaseSelect to your MoSelection tag.

"""
def message(id: int, data: object) -> bool:
    # Called when the tag receives messages. Similar to TagData.Message.
    # Write your code here
    return super().Message(id, data)

def draw(bd: c4d.BaseDraw) -> bool:
    # Called to display some visual element in the viewport. Similar to TagData.Draw.
    # Write your code here
    return True
"""

Dunhou

Hi @Manuel ,

It is pretty strange , I want use python tag because of a I am work with a tag plugin that pin a object of a cloner , now I want add a option to hide the index,
see also : tag plugin crash

And Thanks for @HerrMay , you helped a lot about those tag plugin topics , A big shout out!

HerrMay

Hi @Dunhou and hi @Manuel,

so I found that it is actually possible to modify the flags of the clones via a python tag.

Try the following code on a matrix object. You'll see that the clones will be hidden.

It still seems to be a bug of some sort as you can observe a refresh issue when you scrub the timeline. And of course, if it works on matrix objects only that's not really an option.

Setting a cloner to object mode and cloning on that matrix will also not really work as all clones will still be visible at render time. I tried changing the execution priority of the python tag as well but no luck.

Let's hope @Manuel will come back with good news on that one. Although I'm afraid I already know the answer.

Cheers,
Sebastian

from typing import Optional
import c4d

doc: c4d.documents.BaseDocument # The document evaluating this tag
op: c4d.BaseTag # The Python scripting tag
flags: int # c4d.EXECUTIONFLAGS
priority: int # c4d.EXECUTIONPRIORITY
tp: Optional[c4d.modules.thinkingparticles.TP_MasterSystem] # Particle system
thread: Optional[c4d.threading.BaseThread] # The thread executing this tag

def main() -> None:
    # Called when the tag is executed. It can be called multiple time per frame. Similar to TagData.Execute.
    # Write your code here

    obj = op.GetMain()

    moData = c4d.modules.mograph.GeGetMoData(obj)

    if moData is None:
        return False

    farr = moData.GetArray(c4d.MODATA_FLAGS)
    farr = [1 if i < 5 else 0 for i, num in enumerate(farr)]
    moData.SetArray(c4d.MODATA_FLAGS, farr, False)

"""
def message(id: int, data: object) -> bool:
    # Called when the tag receives messages. Similar to TagData.Message.
    # Write your code here
    return super().Message(id, data)

def draw(bd: c4d.BaseDraw) -> bool:
    # Called to display some visual element in the viewport. Similar to TagData.Draw.
    # Write your code here
    return True
"""

Manuel

hi,

well the main problem is not where but when to change that MoData. Specially in python i see no solution.
With c++ you could find a hacky way of doing it but i did not tried.

One way of doing it would be to create a setup inside the message function of the tag (so you are on the main thread). Creating a formula effector, hide it inside the object manager and use the formula to hide the object you want. something like id!=2&id!=3 will work. Of course, you need to include that effector to the cloner's effector list. I would not call that a "good solution", but it will work.

Cheers,
Manuel.

Dunhou

@Manuel
Oh, what a pitty! I know that I can dot it with a effector, but it is not a "all in one" solution for my convenient，but that's it , I will not spend times in it.

Thanks for your research, and @HerrMay thanks for your enthusiastic answers !

Cheers~
DunHou