Updated mograph selection example to be a bit more sensible.

Author: mxn-ferdinand

scripts/05_modules/mograph/set_modata_selection_r18.py

@@ -0,0 +1,61 @@
+"""Generates and sets a MoGraph selection tag on a MoGraph cloner object.
+
+Effectively, this will create a selection tag for all uneven clones in the cloner object. This script
+has no runtime requirements, as it creates its inputs itself.
+
+Class/method highlighted:
+    - c4d.modules.mograph.GeSetMoDataSelection()
+
+Note:
+
+    This example has been updated as it was a bit thin-lipped in its old form, and uses now some 
+    newer feature of the Python API, such as exposed symbols, type hinting, and streamlined type 
+    validation. This script requires Cinema 4D R2024.0.0 or later due to that. The core functionality
+    of setting a MoGraph selection is available from R18 out, just as its neighboring examples. See
+    older releases of the Python SDK for an R18 version of this example.
+"""
+__author__ = "Maxime Adam, Ferdinand Hoppe"
+__copyright__ = "Maxon Computer GmbH"
+__version__ = "2024.0.0"
+
+import c4d
+import mxutils
+
+doc: c4d.documents.BaseDocument # The active document.
+
+def main() -> None:
+    """Invoked by Cinema 4D when the script is run.
+    """
+    # Create a cloner object in linear mode with 10 clones, a cube object child, a MoGraph 
+    # selection tag on it, and then insert it into the active document.
+    count: int = 10
+    cloner: c4d.BaseObject = mxutils.CheckType(c4d.BaseObject(c4d.Omgcloner))
+    cloner[c4d.ID_MG_MOTIONGENERATOR_MODE] = c4d.ID_MG_MOTIONGENERATOR_MODE_LINEAR
+    cloner[c4d.MG_LINEAR_COUNT] = count
+    cube: c4d.BaseObject = mxutils.CheckType(c4d.BaseObject(c4d.Ocube))
+    cube[c4d.PRIM_CUBE_LEN] = c4d.Vector(10)
+    cube.InsertUnder(cloner)
+
+    tag: c4d.BaseTag = mxutils.CheckType(cloner.MakeTag(c4d.Tmgselection))
+    tag[c4d.MGSELECTIONTAG_NUMBERS] = True  # Enable displaying index numbers in the viewport.
+    tag.SetBit(c4d.BIT_ACTIVE)  # Select the tag, so that the indices are drawn in the viewport.
+
+    doc.InsertObject(cloner)
+
+    # Selections in Cinema 4D are a list of states. When we want to create a selection that selects
+    # all uneven elements, we have to go `False, True, False, True, ...` until we reach the last
+    # element (because the first element is the element with index 0).
+    states: list[bool] = [i % 2 == 1 for i in range(count)]
+    print(f"{states = }")
+
+    # Create a new selection, set our states for the clones, and finally write the selection
+    # to the MoGraph selection tag.
+    selection: c4d.BaseSelect = c4d.BaseSelect()
+    selection.SetAll(states)
+    c4d.modules.mograph.GeSetMoDataSelection(tag, selection)
+
+    # Inform Cinema 4D that the UI should be updated.
+    c4d.EventAdd()
+
+if __name__ == '__main__':
+    main()