Reintroduce improved logic for mesh interior region fill determination (#4464)

node-graph/nodes/vector/src/vector_modification_nodes.rs

@@ -23,6 +23,10 @@ fn path_modify<'e>(
 		modification.apply(&mut element);
 	}
 
+	// Users draw subpaths in arbitrary winding directions, so normalize them here rather than
+	// letting the drawn direction decide fill insideness downstream
+	element.normalize_winding_directions();
+
 	// Set the path to the encapsulating subgraph (drop our own trailing entry from `node_path`),
 	// matching the `path_of_subgraph` proto so editor tools can route data back to the parent layer.
 	let path = match existing.is_empty() {

node-graph/nodes/vector/src/vector_nodes.rs

@@ -1475,9 +1475,11 @@ pub(crate) fn replace_with_polygons(vector: &mut Vector, polygons: Vec<Vec<DVec2
 				if start == end {
 					continue;
 				}
+				// Emit shared walls in index-canonical direction: a cycle can't be monotone in point index,
+				// so no cell's boundary can wind coherently and read as deliberate negative space
 				let edge = if start < end { (start, end) } else { (end, start) };
 				if seen_edges.insert(edge) {
-					segment_domain.push(next_segment.next_id(), start, end, BezierHandles::Linear);
+					segment_domain.push(next_segment.next_id(), edge.0, edge.1, BezierHandles::Linear);
 				}
 			}
 		}