Don't re-scale convex hulls for groups

The convex hulls for groups are already constructed from the convex hull of the convex hulls of all of their children. Since the children's convex hulls are already scaled, we don't want to scale it again for the group.

Contributes to issue CURA-7118.

1 files changed, 4 insertions, 1 deletions

diff --git a/cura/Scene/ConvexHullDecorator.py b/cura/Scene/ConvexHullDecorator.py
index bca3cdc240..5e025a504f 100644
--- a/cura/Scene/ConvexHullDecorator.py
+++ b/cura/Scene/ConvexHullDecorator.py
@@ -381,11 +381,12 @@ class ConvexHullDecorator(SceneNodeDecorator):
         :return: New Polygon instance that is offset with everything that
         influences the collision area.
         """
+        # Shrinkage compensation.
         if not self._global_stack:  # Should never happen.
             return convex_hull
         scale_factor = self._global_stack.getProperty("material_shrinkage_percentage", "value") / 100.0
         result = convex_hull
-        if scale_factor != 1.0:
+        if scale_factor != 1.0 and not self.getNode().callDecoration("isGroup"):
             center = None
             if self._global_stack.getProperty("print_sequence", "value") == "one_at_a_time":
                 # Find the root node that's placed in the scene; the root of the mesh group.
@@ -408,11 +409,13 @@ class ConvexHullDecorator(SceneNodeDecorator):
             if center:
                 result = convex_hull.scale(scale_factor, [center.x, center.z])  # Yes, use Z instead of Y. Mixed conventions there with how the OpenGL coordinates are transmitted.
 
+        # Horizontal expansion.
         horizontal_expansion = max(
             self._getSettingProperty("xy_offset", "value"),
             self._getSettingProperty("xy_offset_layer_0", "value")
         )
 
+        # Mold.
         mold_width = 0
         if self._getSettingProperty("mold_enabled", "value"):
             mold_width = self._getSettingProperty("mold_width", "value")