3D: the group refusal lists groups and clipping groups among what it builds from

The message for a group member that can't become a solid now names groups
and clipping groups too. docs/three-d.md states that an image left out of a
clipping group also needs no visible fills or strokes of its own.

crates/effects/src/solids.rs

@@ -318,7 +318,7 @@ pub(crate) fn members(n: &Node, label: &str) -> Result<Vec<Profile>, String> {
                     _ => "other objects",
                 };
                 return Err(format!(
-                    "{label} on a group needs paths, compound paths, type, blends and symbol instances: release or expand its {what} first."
+                    "{label} on a group needs paths, compound paths, type, groups, clipping groups, blends and symbol instances: release or expand its {what} first."
                 ));
             };
             if w.out.len() >= MAX_MEMBERS {

crates/effects/src/solids/tests.rs

@@ -598,6 +598,7 @@ fn a_3d_effect_on_a_group_turns_every_member_about_one_shared_axis() {
     }
     let err = validate_solid(&g, EXTRUDE, &json!({})).unwrap_err();
     assert!(err.contains("release or expand its other objects"), "{err}");
+    assert!(err.contains("type, groups, clipping groups, blends and symbol instances"), "{err}");
     assert!(solid_art(&g).is_none(), "drawn as the group it is");
 }
 

docs/three-d.md

@@ -153,8 +153,8 @@ solids are ([Groups](#groups)), turned about one shared axis.
 - An image is refused, alone or in a group: trace it first with Object › Image Trace › Make. The help page routes
   images to 3D through Image Trace ([Create 3D vector artwork](https://helpx.adobe.com/illustrator/desktop/special-effects-styles/create-3d-graphics/create-3d-vector-artwork.html)).
   A hidden image in a group is left out like any hidden member, and so is an image in a clipping group whose bounds
-  lie wholly outside the clipping path's bounds, when neither the image nor a group holding it inside the clipping
-  group has effects.
+  lie wholly outside the clipping path's bounds, when the image has no visible fills or strokes of its own and
+  neither the image nor a group holding it inside the clipping group has effects.
 
 ## Rotate