diff --git a/manimlib/mobject/three_d_shading_utils.py b/manimlib/mobject/three_d_shading_utils.py
index a0fe43c3..4d8d7190 100644
--- a/manimlib/mobject/three_d_shading_utils.py
+++ b/manimlib/mobject/three_d_shading_utils.py
@@ -4,6 +4,8 @@ from manimlib.constants import ORIGIN
 from manimlib.utils.space_ops import get_unit_normal
 
 
+# TODO, these ideas should be deprecated
+
 def get_3d_vmob_gradient_start_and_end_points(vmob):
     return (
         get_3d_vmob_start_corner(vmob),
diff --git a/manimlib/mobject/three_d_utils.py b/manimlib/mobject/three_d_utils.py
index 3138aaa1..46e83165 100644
--- a/manimlib/mobject/three_d_utils.py
+++ b/manimlib/mobject/three_d_utils.py
@@ -6,6 +6,9 @@ from manimlib.utils.space_ops import get_norm
 from manimlib.utils.space_ops import get_unit_normal
 
 
+# TODO, these ideas should be deprecated
+
+
 def get_3d_vmob_gradient_start_and_end_points(vmob):
     return (
         get_3d_vmob_start_corner(vmob),
diff --git a/manimlib/mobject/three_dimensions.py b/manimlib/mobject/three_dimensions.py
index e29ebae8..9033d232 100644
--- a/manimlib/mobject/three_dimensions.py
+++ b/manimlib/mobject/three_dimensions.py
@@ -8,6 +8,9 @@ from manimlib.utils.space_ops import z_to_vector
 ##############
 
 
+# TODO, replace these with a special 3d type, not VMobject
+
+
 class ThreeDVMobject(VMobject):
     CONFIG = {
         "shade_in_3d": True,