# Vector to scalar volume grayed out

**URL:** <https://discourse.slicer.org/t/vector-to-scalar-volume-grayed-out/33832>\
**Category:** Support\
**Tags:** 3d-model\
**Created:** [January 17, 2024, 4:19pm UTC](https://discourse.slicer.org/t/vector-to-scalar-volume-grayed-out/33832 "2024-01-17T16:19:20Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![Andreas\_Vossinakis](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/andreas_vossinakis/32/68985_2.png) [@Andreas\_Vossinakis](https://discourse.slicer.org/u/Andreas_Vossinakis)\
**Post date:** [January 17, 2024, 4:19pm UTC](https://discourse.slicer.org/t/vector-to-scalar-volume-grayed-out/33832/1 "2024-01-17T16:19:20Z")

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Hi, I load the images in a volume but when I try to convert this volume to a scalar volume, the ‘input vector volume’ dropdown menu is grayed and I can’t choose the volume I work on. Please help

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**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [January 17, 2024, 4:31pm UTC](https://discourse.slicer.org/t/vector-to-scalar-volume-grayed-out/33832/2 "2024-01-17T16:31:28Z")

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Make sure you indeed have vector volume loaded into the scene:

Right click on the Volume, choose “Edit Properties” and then in the opened `Volumes` module, navigate to the Volume Information and look at the **Volume type r** eported

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/6/5/6580c13b2253c1dd8e15d87d56ea17a9c1ac9cce.png)

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**Author:** ![Andreas\_Vossinakis](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/andreas_vossinakis/32/68985_2.png) [@Andreas\_Vossinakis](https://discourse.slicer.org/u/Andreas_Vossinakis)\
**Post date:** [January 18, 2024, 7:43am UTC](https://discourse.slicer.org/t/vector-to-scalar-volume-grayed-out/33832/3 "2024-01-18T07:43:40Z")

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Hi, thanks for your reply. These are the volume properties  
 ![2024-01-18_094039](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/7/e/7e0ee26bba2f01122369e10609c27c41d8f2ae3e.jpeg)

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**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [January 18, 2024, 3:13pm UTC](https://discourse.slicer.org/t/vector-to-scalar-volume-grayed-out/33832/4 "2024-01-18T15:13:40Z")

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That’s the issue. You don’t have a vector volume, but a scalar one. So the input node selector is grayed out.

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<div class="post-metadata">

**Author:** ![Andreas\_Vossinakis](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/andreas_vossinakis/32/68985_2.png) [@Andreas\_Vossinakis](https://discourse.slicer.org/u/Andreas_Vossinakis)\
**Post date:** [January 19, 2024, 7:31am UTC](https://discourse.slicer.org/t/vector-to-scalar-volume-grayed-out/33832/5 "2024-01-19T07:31:35Z")

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Can I convert the scalar volume to a vector one??

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<div class="post-metadata">

**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [January 19, 2024, 3:42pm UTC](https://discourse.slicer.org/t/vector-to-scalar-volume-grayed-out/33832/6 "2024-01-19T15:42:54Z")

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You can, but it will be somewhat pointless. All three channels of the vector volume will contain the same value as the original scalar volume.

What are you trying to accomplish?

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<div class="post-metadata">

**Author:** ![Andreas\_Vossinakis](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/andreas_vossinakis/32/68985_2.png) [@Andreas\_Vossinakis](https://discourse.slicer.org/u/Andreas_Vossinakis)\
**Post date:** [January 19, 2024, 3:43pm UTC](https://discourse.slicer.org/t/vector-to-scalar-volume-grayed-out/33832/7 "2024-01-19T15:43:46Z")

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I have a set of images and I want to make a 3d model

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<div class="post-metadata">

**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [January 19, 2024, 4:14pm UTC](https://discourse.slicer.org/t/vector-to-scalar-volume-grayed-out/33832/8 "2024-01-19T16:14:06Z")

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That’s usually done by segmentation. And segmentation works on scalar volumes, not vectors ones. I would suggest making yourself familiar with the Slicer documentation, particularly the section on Image Segmentation. [https://slicer.readthedocs.io](https://slicer.readthedocs.io)