fixed block for 3D ROI

src/main/java/plugins/adufour/roi/Convexify.java

@@ -141,9 +141,9 @@ public class Convexify extends EzPlug implements ROIBlock
                 output = new ROI3DPolygonalMesh(qhull);
 
                 // copy position info
-                final ROI3D roi2d = (ROI3D) roi;
-                ((ROI3D) output).setT(roi2d.getT());
-                ((ROI2D) output).setC(roi2d.getC());
+                final ROI3D roi3d = (ROI3D) roi;
+                ((ROI3D)output).setT(roi3d.getT());
+                ((ROI3D)output).setC(roi3d.getC());
             }
         }
         catch (Throwable t)