5 files changed, 23 insertions, 12 deletions
diff --git a/modules/csg/csg_gizmos.cpp b/modules/csg/csg_gizmos.cpp
index 71891c8704..9a6a33fad3 100644
--- a/modules/csg/csg_gizmos.cpp
+++ b/modules/csg/csg_gizmos.cpp
@@ -50,7 +50,7 @@ CSGShape3DGizmoPlugin::CSGShape3DGizmoPlugin() {
 	create_handle_material("handles");
 }
 
-String CSGShape3DGizmoPlugin::get_handle_name(const EditorNode3DGizmo *p_gizmo, int p_id) const {
+String CSGShape3DGizmoPlugin::get_handle_name(const EditorNode3DGizmo *p_gizmo, int p_id, bool p_secondary) const {
 	CSGShape3D *cs = Object::cast_to<CSGShape3D>(p_gizmo->get_spatial_node());
 
 	if (Object::cast_to<CSGSphere3D>(cs)) {
@@ -72,7 +72,7 @@ String CSGShape3DGizmoPlugin::get_handle_name(const EditorNode3DGizmo *p_gizmo,
 	return "";
 }
 
-Variant CSGShape3DGizmoPlugin::get_handle_value(const EditorNode3DGizmo *p_gizmo, int p_id) const {
+Variant CSGShape3DGizmoPlugin::get_handle_value(const EditorNode3DGizmo *p_gizmo, int p_id, bool p_secondary) const {
 	CSGShape3D *cs = Object::cast_to<CSGShape3D>(p_gizmo->get_spatial_node());
 
 	if (Object::cast_to<CSGSphere3D>(cs)) {
@@ -98,7 +98,7 @@ Variant CSGShape3DGizmoPlugin::get_handle_value(const EditorNode3DGizmo *p_gizmo
 	return Variant();
 }
 
-void CSGShape3DGizmoPlugin::set_handle(const EditorNode3DGizmo *p_gizmo, int p_id, Camera3D *p_camera, const Point2 &p_point) {
+void CSGShape3DGizmoPlugin::set_handle(const EditorNode3DGizmo *p_gizmo, int p_id, bool p_secondary, Camera3D *p_camera, const Point2 &p_point) {
 	CSGShape3D *cs = Object::cast_to<CSGShape3D>(p_gizmo->get_spatial_node());
 
 	Transform3D gt = cs->get_global_transform();
@@ -201,7 +201,7 @@ void CSGShape3DGizmoPlugin::set_handle(const EditorNode3DGizmo *p_gizmo, int p_i
 	}
 }
 
-void CSGShape3DGizmoPlugin::commit_handle(const EditorNode3DGizmo *p_gizmo, int p_id, const Variant &p_restore, bool p_cancel) {
+void CSGShape3DGizmoPlugin::commit_handle(const EditorNode3DGizmo *p_gizmo, int p_id, bool p_secondary, const Variant &p_restore, bool p_cancel) {
 	CSGShape3D *cs = Object::cast_to<CSGShape3D>(p_gizmo->get_spatial_node());
 
 	if (Object::cast_to<CSGSphere3D>(cs)) {
@@ -343,6 +343,16 @@ void CSGShape3DGizmoPlugin::redraw(EditorNode3DGizmo *p_gizmo) {
 	p_gizmo->add_lines(lines, material);
 	p_gizmo->add_collision_segments(lines);
 
+	Array csg_meshes = cs->get_meshes();
+	if (csg_meshes.size() != 2) {
+		return;
+	}
+
+	Ref<Mesh> csg_mesh = csg_meshes[1];
+	if (csg_mesh.is_valid()) {
+		p_gizmo->add_collision_triangles(csg_mesh->generate_triangle_mesh());
+	}
+
 	if (p_gizmo->is_selected()) {
 		// Draw a translucent representation of the CSG node
 		Ref<ArrayMesh> mesh = memnew(ArrayMesh);
diff --git a/modules/csg/csg_gizmos.h b/modules/csg/csg_gizmos.h
index 1dcee642c7..46761370dd 100644
--- a/modules/csg/csg_gizmos.h
+++ b/modules/csg/csg_gizmos.h
@@ -45,10 +45,10 @@ public:
 	virtual bool is_selectable_when_hidden() const override;
 	virtual void redraw(EditorNode3DGizmo *p_gizmo) override;
 
-	virtual String get_handle_name(const EditorNode3DGizmo *p_gizmo, int p_id) const override;
-	virtual Variant get_handle_value(const EditorNode3DGizmo *p_gizmo, int p_id) const override;
-	virtual void set_handle(const EditorNode3DGizmo *p_gizmo, int p_id, Camera3D *p_camera, const Point2 &p_point) override;
-	virtual void commit_handle(const EditorNode3DGizmo *p_gizmo, int p_id, const Variant &p_restore, bool p_cancel) override;
+	virtual String get_handle_name(const EditorNode3DGizmo *p_gizmo, int p_id, bool p_secondary) const override;
+	virtual Variant get_handle_value(const EditorNode3DGizmo *p_gizmo, int p_id, bool p_secondary) const override;
+	virtual void set_handle(const EditorNode3DGizmo *p_gizmo, int p_id, bool p_secondary, Camera3D *p_camera, const Point2 &p_point) override;
+	virtual void commit_handle(const EditorNode3DGizmo *p_gizmo, int p_id, bool p_secondary, const Variant &p_restore, bool p_cancel) override;
 
 	CSGShape3DGizmoPlugin();
 };
diff --git a/modules/csg/csg_shape.cpp b/modules/csg/csg_shape.cpp
index 41b4682c84..4b36bca02a 100644
--- a/modules/csg/csg_shape.cpp
+++ b/modules/csg/csg_shape.cpp
@@ -1694,7 +1694,7 @@ CSGBrush *CSGPolygon3D::_build_brush() {
 	}
 	int shape_sides = shape_polygon.size();
 	Vector<int> shape_faces = Geometry2D::triangulate_polygon(shape_polygon);
-	ERR_FAIL_COND_V_MSG(shape_faces.size() < 3, brush, "Failed to triangulate CSGPolygon");
+	ERR_FAIL_COND_V_MSG(shape_faces.size() < 3, brush, "Failed to triangulate CSGPolygon. Make sure the polygon doesn't have any intersecting edges.");
 
 	// Get polygon enclosing Rect2.
 	Rect2 shape_rect(shape_polygon[0], Vector2());
diff --git a/modules/csg/doc_classes/CSGMesh3D.xml b/modules/csg/doc_classes/CSGMesh3D.xml
index 2810343139..42fcb7bd2b 100644
--- a/modules/csg/doc_classes/CSGMesh3D.xml
+++ b/modules/csg/doc_classes/CSGMesh3D.xml
@@ -4,7 +4,7 @@
 		A CSG Mesh shape that uses a mesh resource.
 	</brief_description>
 	<description>
-		This CSG node allows you to use any mesh resource as a CSG shape, provided it is closed, does not self-intersect, does not contain internal faces and has no edges that connect to more than two faces.
+		This CSG node allows you to use any mesh resource as a CSG shape, provided it is closed, does not self-intersect, does not contain internal faces and has no edges that connect to more than two faces. See also [CSGPolygon3D] for drawing 2D extruded polygons to be used as CSG nodes.
 	</description>
 	<tutorials>
 	</tutorials>
diff --git a/modules/csg/doc_classes/CSGPolygon3D.xml b/modules/csg/doc_classes/CSGPolygon3D.xml
index ecbb7962d1..5a49eebc7b 100644
--- a/modules/csg/doc_classes/CSGPolygon3D.xml
+++ b/modules/csg/doc_classes/CSGPolygon3D.xml
@@ -4,7 +4,7 @@
 		Extrudes a 2D polygon shape to create a 3D mesh.
 	</brief_description>
 	<description>
-		An array of 2D points is extruded to quickly and easily create a variety of 3D meshes.
+		An array of 2D points is extruded to quickly and easily create a variety of 3D meshes. See also [CSGMesh3D] for using 3D meshes as CSG nodes.
 	</description>
 	<tutorials>
 	</tutorials>
@@ -46,7 +46,8 @@
 			When [member mode] is [constant MODE_PATH], this is the distance along the path, in meters, the texture coordinates will tile. When set to 0, texture coordinates will match geometry exactly with no tiling.
 		</member>
 		<member name="polygon" type="PackedVector2Array" setter="set_polygon" getter="get_polygon" default="PackedVector2Array(0, 0, 0, 1, 1, 1, 1, 0)">
-			The point array that defines the 2D polygon that is extruded.
+			The point array that defines the 2D polygon that is extruded. This can be a convex or concave polygon with 3 or more points. The polygon must [i]not[/i] have any intersecting edges. Otherwise, triangulation will fail and no mesh will be generated.
+			[b]Note:[/b] If only 1 or 2 points are defined in [member polygon], no mesh will be generated.
 		</member>
 		<member name="smooth_faces" type="bool" setter="set_smooth_faces" getter="get_smooth_faces" default="false">
 			If [code]true[/code], applies smooth shading to the extrusions.