# Shift in Volume Render - Better than I can segment bones

**URL:** <https://discourse.slicer.org/t/shift-in-volume-render-better-than-i-can-segment-bones/2488>\
**Category:** Support\
**Tags:** segmentation\
**Created:** [April 1, 2018, 3:24pm UTC](https://discourse.slicer.org/t/shift-in-volume-render-better-than-i-can-segment-bones/2488 "2018-04-01T15:24:38Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![brockgs](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/brockgs/32/1359_2.png) [@brockgs](https://discourse.slicer.org/u/brockgs)\
**Post date:** [April 1, 2018, 3:24pm UTC](https://discourse.slicer.org/t/shift-in-volume-render-better-than-i-can-segment-bones/2488/1 "2018-04-01T15:24:38Z")

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Scenario: When I load a DICOM series of a head, If I go straight to Volume Render and use one of the bone presents, and then slide the “Shift” slider all the way to the right, I get an almost perfectly cleaned up view of all the bones, surgical implants and orthodontics. When I go to the Segment Editor and follow along with the various tutorials to attempt to segment out the bones and implants, I can get something somewhat close…but really no where near the sharpness and accuracy of what the “Shift” operation produces on the unsegmented volume using either of the bone presets.

Question: Is there a way to create a model (or a segment) of what is rendered in Volume Render screen after tweaking the presents and “Shift”?

Thank you.

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [April 1, 2018, 5:46pm UTC](https://discourse.slicer.org/t/shift-in-volume-render-better-than-i-can-segment-bones/2488/2 "2018-04-01T17:46:24Z")

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Hi -

This question comes up from time to time - have a look at this discussion for background on this:

> [@Save volume rendering as STL file](https://discourse.slicer.org/t/save-volume-rendering-as-stl-file/524/6):
>
> Semi-transparent volumetric cloud = your image data, so you already have it. No processing is performed on the data, it is visualized directly using [raycasting](https://en.wikipedia.org/wiki/Volume_rendering). Volume rendering visualization parameters are mostly defined by transfer functions (opacity, color, gradient), which are saved in the Slicer scene. STL file cannot store volumetric cloud, it only stores a surface mesh = hard boundary of your printed object. What confuses most people that volume rendering may give the illusion that ther…

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**Author:** ![brockgs](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/brockgs/32/1359_2.png) [@brockgs](https://discourse.slicer.org/u/brockgs)\
**Post date:** [April 1, 2018, 6:34pm UTC](https://discourse.slicer.org/t/shift-in-volume-render-better-than-i-can-segment-bones/2488/3 "2018-04-01T18:34:18Z")

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Thank you for pointing me to that thread. I remembered as soon as I clicked over to it, that I had read it a few weeks ago and forgotten about those “small” but critical differences between volumetric rendering and the creation of actual 3d meshes that are the output of segmentation.