# Is there a segmentation mapper available in VTK/VTK.js?
**URL:** https://discourse.vtk.org/t/is-there-a-segmentation-mapper-available-in-vtk-vtk-js/16459
**Category:** Web
**Created:** [June 15, 2026, 9:53pm UTC](https://discourse.vtk.org/t/is-there-a-segmentation-mapper-available-in-vtk-vtk-js/16459 "2026-06-15T21:53:05Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Pranathi\_Induri](https://discourse.vtk.org/u/Pranathi_Induri)
#### Post date: [June 15, 2026, 9:53pm UTC](https://discourse.vtk.org/t/is-there-a-segmentation-mapper-available-in-vtk-vtk-js/16459/1 "2026-06-15T21:53:05Z")
Hi everyone,
I am working on a medical imaging viewer using VTK/VTK.js for DICOM volume rendering. I wanted to understand whether VTK has a built-in **segmentation mapper** or recommended pipeline for displaying segmentation masks over a CT/MRI volume.
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### Author:  [@PaulHax](https://discourse.vtk.org/u/PaulHax)
#### Post date: [June 18, 2026, 8:54pm UTC](https://discourse.vtk.org/t/is-there-a-segmentation-mapper-available-in-vtk-vtk-js/16459/2 "2026-06-18T20:54:02Z")
Here is a 2D slice example:
> **[VTK.js | Example - ImageResliceMapperLabelOutline](https://kitware.github.io/vtk-js/examples/ImageResliceMapperLabelOutline/index.html)**
If you use the Volumn dropdown to change to “sphere labelmap volume” in this example there is a volumn mapper approach:
> **[VTK.js | Example - VolumeMapper](https://kitware.github.io/vtk-js/examples/VolumeMapper/index.html)**
Some folk convert their lablemaps to polydatas via marching cubes and render that together with the volumn mapper. See:
>
>
> Ideally this will be a polygonal representation, as mixed volumes in vtk.js is n…ot yet supported.
and
> **[GitHub - PaulHax/labelmap-polydata: Convert ImageData labelmap to PolyData meshes...](https://github.com/PaulHax/labelmap-polydata)**
>
> Convert ImageData labelmap to PolyData meshes using marching cubes.