Update standard_material_3d.rst to Godot 4 (#9641)

* Depth renamed to Height in Standard Material 3D

tutorials/3d/standard_material_3d.rst

@@ -455,12 +455,13 @@ AO map. It is recommended to bake ambient occlusion whenever possible.
 Height
 ------
 
-
-Setting a depth map on a material produces a ray-marched search to emulate the
-proper displacement of cavities along the view direction. This is not real
-added geometry, but an illusion of depth. It may not work for complex objects,
-but it produces a realistic depth effect for textures. For best results,
-*Depth* should be used together with normal mapping.
+Setting a height map on a material produces a ray-marched search to emulate the
+proper displacement of cavities along the view direction. This only creates an
+illusion of depth, and does not add real geometry — for a height map shape used
+for physics collision (such as terrain), see :ref:`class_HeightMapShape3D`. It
+may not work for complex objects, but it produces a realistic depth effect for
+textures. For best results, *Height* should be used together with normal
+mapping.
 
 .. image:: img/spatial_material20.png