By default, segmentation segments are shown in slice views as consisting only of whole voxels, which is how their binary labelmap representations are encoded. Each voxel of the segmentation volume is either part of the segment or not part of the segment. If this view is too “pixelated” for you, there are two ways to address this: 1) Increase the resolution of the segmentation volume so that the stair steps are smaller, or 2) display a smoothed model representation on slice views instead of the binary label map representation.
There are many other posts in this forum about how to do option 1. Here’s one which might be helpful: How do I set segmentation resolution
For option 2, if you go to the Segmentations module, you can select to show the smoothed “Closed surface” representation in slice views instead of the “Binary labelmap”. This will not change your underlying segmentation at all, just the view you are seeing of it.
