Fix build with disable_3d=yes, remove dependency on WorldEnvironment

scene/3d/SCsub

@@ -3,10 +3,7 @@
 Import('env')
 
 if env['disable_3d']:
-    env.add_source_files(env.scene_sources, "spatial.cpp")
-    env.add_source_files(env.scene_sources, "skeleton.cpp")
-    env.add_source_files(env.scene_sources, "particles.cpp")
-    env.add_source_files(env.scene_sources, "visual_instance.cpp")
-    env.add_source_files(env.scene_sources, "world_environment.cpp")
+    env.add_source_files(env.scene_sources, "node_3d.cpp")
+    env.add_source_files(env.scene_sources, "skeleton_3d.cpp")
 else:
     env.add_source_files(env.scene_sources, "*.cpp")

scene/main/viewport.cpp

@@ -1223,17 +1223,20 @@ void Viewport::_propagate_enter_world(Node *p_node) {
 		if (!p_node->is_inside_tree()) //may not have entered scene yet
 			return;
 
+#ifndef _3D_DISABLED
 		if (Object::cast_to<Node3D>(p_node) || Object::cast_to<WorldEnvironment>(p_node)) {
-
 			p_node->notification(Node3D::NOTIFICATION_ENTER_WORLD);
 		} else {
+#endif
 			Viewport *v = Object::cast_to<Viewport>(p_node);
 			if (v) {
 
 				if (v->world.is_valid() || v->own_world.is_valid())
 					return;
 			}
+#ifndef _3D_DISABLED
 		}
+#endif
 	}
 
 	for (int i = 0; i < p_node->get_child_count(); i++) {
@@ -1260,17 +1263,20 @@ void Viewport::_propagate_exit_world(Node *p_node) {
 		if (!p_node->is_inside_tree()) //may have exited scene already
 			return;
 
+#ifndef _3D_DISABLED
 		if (Object::cast_to<Node3D>(p_node) || Object::cast_to<WorldEnvironment>(p_node)) {
-
 			p_node->notification(Node3D::NOTIFICATION_EXIT_WORLD);
 		} else {
+#endif
 			Viewport *v = Object::cast_to<Viewport>(p_node);
 			if (v) {
 
 				if (v->world.is_valid() || v->own_world.is_valid())
 					return;
 			}
+#ifndef _3D_DISABLED
 		}
+#endif
 	}
 
 	for (int i = 0; i < p_node->get_child_count(); i++) {

scene/register_scene_types.cpp

@@ -173,6 +173,10 @@
 #include "scene/resources/world_margin_shape_3d.h"
 #include "scene/scene_string_names.h"
 
+// Needed by animation code, so keep when 3D disabled.
+#include "scene/3d/node_3d.h"
+#include "scene/3d/skeleton_3d.h"
+
 #ifndef _3D_DISABLED
 #include "scene/3d/area_3d.h"
 #include "scene/3d/arvr_nodes.h"
@@ -186,7 +190,6 @@
 #include "scene/3d/gi_probe.h"
 #include "scene/3d/gpu_particles_3d.h"
 #include "scene/3d/immediate_geometry_3d.h"
-
 #include "scene/3d/light_3d.h"
 #include "scene/3d/listener_3d.h"
 #include "scene/3d/mesh_instance_3d.h"
@@ -195,7 +198,6 @@
 #include "scene/3d/navigation_agent_3d.h"
 #include "scene/3d/navigation_obstacle_3d.h"
 #include "scene/3d/navigation_region_3d.h"
-#include "scene/3d/node_3d.h"
 #include "scene/3d/path_3d.h"
 #include "scene/3d/physics_body_3d.h"
 #include "scene/3d/physics_joint_3d.h"
@@ -204,7 +206,6 @@
 #include "scene/3d/ray_cast_3d.h"
 #include "scene/3d/reflection_probe.h"
 #include "scene/3d/remote_transform_3d.h"
-#include "scene/3d/skeleton_3d.h"
 #include "scene/3d/soft_body_3d.h"
 #include "scene/3d/spring_arm_3d.h"
 #include "scene/3d/sprite_3d.h"
@@ -367,12 +368,13 @@ void register_scene_types() {
 
 	/* REGISTER 3D */
 
-	ClassDB::register_class<Skin>();
-	ClassDB::register_virtual_class<SkinReference>();
-
+	// Needed even with _3D_DISABLED as used in animation code.
 	ClassDB::register_class<Node3D>();
 	ClassDB::register_virtual_class<Node3DGizmo>();
+	ClassDB::register_class<Skin>();
+	ClassDB::register_virtual_class<SkinReference>();
 	ClassDB::register_class<Skeleton3D>();
+
 	ClassDB::register_class<AnimationPlayer>();
 	ClassDB::register_class<Tween>();