matplotlib · vagnermcj · May 26, 2025 · May 27, 2025 · May 27, 2025 · May 27, 2025
diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
@@ -963,6 +963,28 @@
         self.update_from_path(path, ignore=ignore,
                               updatex=updatex, updatey=updatey)
 
+    def update_from_bbox(self, bbox, ignore=False, updatex=True, updatey=True):
+        """
+        Update the Bbox to include another Bbox.
+
+        This is equivalent to performing an in-place union of this Bbox with *bbox*.
+
+        Parameters
+        ----------
+        bbox3d : Bbox3d
+            The Bbox to merge into this one.
+        ignore : bool, default: False
+            Whether to ignore the current bounds (start fresh) or not.
+        updatex, updatey : bool, default: True
+            Whether to update the x/y dimensions.
+        """
+        if not updatex and not updatey:
+            return
+
+        vertices = np.array([[bbox.x0, bbox.y0],[bbox.x1, bbox.y1]])
+        path = Path(vertices)
+        self.update_from_path(path, ignore=ignore, updatex=updatex, updatey=updatey)
+
     @BboxBase.x0.setter
     def x0(self, val):
         self._points[0, 0] = val

diff --git a/lib/matplotlib/transforms.pyi b/lib/matplotlib/transforms.pyi
@@ -129,6 +129,7 @@ class Bbox(BboxBase):
         updatex: bool = ...,
         updatey: bool = ...,
     ) -> None: ...
+    def update_from_bbox(self, bbox: Bbox, ignore: bool = ..., updatex: bool = ..., updatey: bool = ...) -> None: ...
     @property
     def minpos(self) -> float: ...
     @property

diff --git a/lib/mpl_toolkits/mplot3d/art3d.py b/lib/mpl_toolkits/mplot3d/art3d.py
@@ -20,6 +20,7 @@
     Collection, LineCollection, PolyCollection, PatchCollection, PathCollection)
 from matplotlib.patches import Patch
 from . import proj3d
+from .bbox3d import _Bbox3d
 
 
 def _norm_angle(a):
@@ -97,6 +98,16 @@
     return mask
 
 
+def create_bbox3d_from_array(arr):
+    arr = np.asarray(arr)
+    if arr.ndim != 2 or arr.shape[1] != 3:
+        raise ValueError("Expected array of shape (N, 3)")
+    xmin, xmax = np.min(arr[:, 0]), np.max(arr[:, 0])
+    ymin, ymax = np.min(arr[:, 1]), np.max(arr[:, 1])
+    zmin, zmax = np.min(arr[:, 2]), np.max(arr[:, 2])
+    return _Bbox3d(((xmin, xmax), (ymin, ymax), (zmin, zmax)))
+
+
 class Text3D(mtext.Text):
     """
     Text object with 3D position and direction.
@@ -331,6 +342,10 @@
         super().draw(renderer)
         self.stale = False
 
+    def _get_datalim3d(self):
+        xs, ys, zs = self._verts3d
+        return create_bbox3d_from_array(np.column_stack((xs, ys, zs)))
+
 
 def line_2d_to_3d(line, zs=0, zdir='z', axlim_clip=False):
     """
@@ -513,6 +528,10 @@
             minz = np.nan
         return minz
 
+    def _get_datalim3d(self):
+        segments = np.concatenate(self._segments3d)
+        return create_bbox3d_from_array(segments)
+
 
 def line_collection_2d_to_3d(col, zs=0, zdir='z', axlim_clip=False):
     """Convert a `.LineCollection` to a `.Line3DCollection` object."""
@@ -591,6 +610,9 @@
         self._path2d = mpath.Path(np.ma.column_stack([vxs, vys]))
         return min(vzs)
 
+    def _get_datalim3d(self):
+        return create_bbox3d_from_array(self._segment3d)
+
 
 class PathPatch3D(Patch3D):
     """
@@ -653,6 +675,9 @@
         self._path2d = mpath.Path(np.ma.column_stack([vxs, vys]), self._code3d)
         return min(vzs)
 
+    def _get_datalim3d(self):
+        return create_bbox3d_from_array(self._segment3d)
+
 
 def _get_patch_verts(patch):
     """Return a list of vertices for the path of a patch."""
@@ -832,6 +857,10 @@
             return self.get_facecolor()
         return self._maybe_depth_shade_and_sort_colors(super().get_edgecolor())
 
+    def _get_datalim3d(self):
+        xs, ys, zs = self._offsets3d
+        return create_bbox3d_from_array(np.column_stack((xs, ys, zs)))
+
 
 def _get_data_scale(X, Y, Z):
     """
@@ -1087,6 +1116,10 @@
             return self.get_facecolor()
         return self._maybe_depth_shade_and_sort_colors(super().get_edgecolor())
 
+    def _get_datalim3d(self):
+        xs, ys, zs = self._offsets3d
+        return create_bbox3d_from_array(np.column_stack((xs, ys, zs)))
+
 
 def patch_collection_2d_to_3d(
     col,
@@ -1464,6 +1497,9 @@
             self.do_3d_projection()
         return np.asarray(self._edgecolors2d)
 
+    def _get_datalim3d(self):
+        return create_bbox3d_from_array(self._faces.reshape(-1, 3))
+
 
 def poly_collection_2d_to_3d(col, zs=0, zdir='z', axlim_clip=False):
     """

diff --git a/lib/mpl_toolkits/mplot3d/axes3d.py b/lib/mpl_toolkits/mplot3d/axes3d.py
@@ -608,6 +608,25 @@ def auto_scale_xyz(self, X, Y, Z=None, had_data=None):
         # Let autoscale_view figure out how to use this data.
         self.autoscale_view()
 
+    def auto_scale_lim(self, bbox3d, had_data=False):
+        """
+        Expand the 3D axes data limits to include the given Bbox3d.
+
+        Parameters
+        ----------
+        bbox3d : _Bbox3d
+            The 3D bounding box to incorporate into the data limits.
+        had_data : bool, default: False
+            Whether the axes already had data limits set before.
+        """
+        self.xy_dataLim.update_from_bbox(bbox3d.to_bbox_xy(), ignore=not had_data)
+        self.zz_dataLim.update_from_bbox(bbox3d.to_bbox_zz(), ignore=not had_data)
+        if not had_data:
+            self._xy_dataLim_set = True
+            self._zz_dataLim_set = True
+        self.autoscale_view()
+
+
     def autoscale_view(self, tight=None,
                        scalex=True, scaley=True, scalez=True):
         """
@@ -2887,19 +2906,9 @@ def add_collection3d(self, col, zs=0, zdir='z', autolim=True, *,
                                             axlim_clip=axlim_clip)
             col.set_sort_zpos(zsortval)
 
-        if autolim:
-            if isinstance(col, art3d.Line3DCollection):
-                self.auto_scale_xyz(*np.array(col._segments3d).transpose(),
-                                    had_data=had_data)
-            elif isinstance(col, art3d.Poly3DCollection):
-                self.auto_scale_xyz(col._faces[..., 0],
-                                    col._faces[..., 1],
-                                    col._faces[..., 2], had_data=had_data)
-            elif isinstance(col, art3d.Patch3DCollection):
-                pass
-                # FIXME: Implement auto-scaling function for Patch3DCollection
-                # Currently unable to do so due to issues with Patch3DCollection
-                # See https://github.com/matplotlib/matplotlib/issues/14298 for details
+        if autolim and hasattr(col, "_get_datalim3d"):
+            bbox3d = col._get_datalim3d()
+            self.auto_scale_lim(bbox3d, had_data=had_data)
 
         collection = super().add_collection(col)
         return collection

diff --git a/lib/mpl_toolkits/mplot3d/bbox3d.py b/lib/mpl_toolkits/mplot3d/bbox3d.py
@@ -0,0 +1,39 @@
+from matplotlib.transforms import Bbox
+
+
+class _Bbox3d:
+    """
+    A helper class to represent a 3D bounding box.
+
+    This class stores the minimum and maximum extents of data in 3D space
+    (xmin, xmax, ymin, ymax, zmin, zmax). It provides methods to convert
+    these extents into 2D bounding boxes (`Bbox`) for compatibility with
+    existing matplotlib functionality.
+
+    Attributes
+    ----------
+    xmin, xmax : float
+        The minimum and maximum extents along the x-axis.
+    ymin, ymax : float
+        The minimum and maximum extents along the y-axis.
+    zmin, zmax : float
+        The minimum and maximum extents along the z-axis.
+
+    Methods
+    -------
+    to_bbox_xy():
+        Converts the x and y extents into a 2D `Bbox`.
+    to_bbox_zz():
+        Converts the z extents into a 2D `Bbox`, with the y-component unused.
+    """
+    def __init__(self, points):
+        ((self.xmin, self.xmax),
+         (self.ymin, self.ymax),
+         (self.zmin, self.zmax)) = points
+
+    def to_bbox_xy(self):
+        return Bbox(((self.xmin, self.ymin), (self.xmax, self.ymax)))
+
+    def to_bbox_zz(self):
+        # first component contains z, second is unused
+        return Bbox(((self.zmin, 0), (self.zmax, 0)))
diff --git a/lib/mpl_toolkits/mplot3d/meson.build b/lib/mpl_toolkits/mplot3d/meson.build
@@ -4,6 +4,7 @@ python_sources = [
   'axes3d.py',
   'axis3d.py',
   'proj3d.py',
+  'bbox3d.py'
 ]
 
 py3.install_sources(python_sources, subdir: 'mpl_toolkits/mplot3d')