From faea09e7ef2667aad5cef1efc2a6516677ca2915 Mon Sep 17 00:00:00 2001
From: Devu-trenser <91659097+Devu-trenser@users.noreply.github.com>
Date: Wed, 15 Oct 2025 19:05:26 +0530
Subject: [PATCH] fix: Segmentation not displayed and unable to draw segments
 in volume viewport after converting Labelmap to Surface (#5488)

* fix: unable to draw segment after 3d layout

* comment update

---------
---
 .../createHydrateSegmentationSynchronizer.ts      | 12 +++++-------
 .../ViewportService/CornerstoneViewportService.ts | 15 +++++----------
 2 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/extensions/cornerstone/src/services/SyncGroupService/createHydrateSegmentationSynchronizer.ts b/extensions/cornerstone/src/services/SyncGroupService/createHydrateSegmentationSynchronizer.ts
index f72c7f89f..f20bbd6b8 100644
--- a/extensions/cornerstone/src/services/SyncGroupService/createHydrateSegmentationSynchronizer.ts
+++ b/extensions/cornerstone/src/services/SyncGroupService/createHydrateSegmentationSynchronizer.ts
@@ -65,13 +65,11 @@ const segmentationRepresentationModifiedCallback = async (
     return;
   }
 
-  // whatever type the source viewport has, we need to add that to the target viewport
-  const sourceViewportRepresentation = segmentationService.getSegmentationRepresentations(
-    sourceViewport.viewportId,
-    { segmentationId }
-  );
-
-  const type = sourceViewportRepresentation[0].type;
+  // Ensure the segmentation representation aligns with the target viewport type.
+  const type: Enums.SegmentationRepresentations =
+    viewport.type === CoreEnums.ViewportType.VOLUME_3D
+      ? Enums.SegmentationRepresentations.Surface
+      : Enums.SegmentationRepresentations.Labelmap;
 
   await segmentationService.addSegmentationRepresentation(targetViewportId, {
     segmentationId,
diff --git a/extensions/cornerstone/src/services/ViewportService/CornerstoneViewportService.ts b/extensions/cornerstone/src/services/ViewportService/CornerstoneViewportService.ts
index 765ab204d..319817ee9 100644
--- a/extensions/cornerstone/src/services/ViewportService/CornerstoneViewportService.ts
+++ b/extensions/cornerstone/src/services/ViewportService/CornerstoneViewportService.ts
@@ -1336,17 +1336,12 @@ class CornerstoneViewportService extends PubSubService implements IViewportServi
       const { segmentationId, type, hydrated } = presentationItem;
 
       const { Labelmap, Surface } = csToolsEnums.SegmentationRepresentations;
-      const representationType = (() => {
-        if (type === Surface) {
-          if (viewport.type === csEnums.ViewportType.VOLUME_3D) {
-            return Surface;
-          } else {
-            return Labelmap;
-          }
-        }
+      const isVolume3D = viewport.type === csEnums.ViewportType.VOLUME_3D;
 
-        return type;
-      })();
+      // Determine the appropriate segmentation representation for the viewport.
+      // If the current type is Surface but the viewport is not 3D, fallback to Labelmap.
+      // Otherwise, use the existing type.
+      const representationType = type === Surface && !isVolume3D ? Labelmap : type;
 
       if (hydrated) {
         segmentationService.addSegmentationRepresentation(viewport.id, {