How to export the Volume Rendering into models?


(Dr.Xie) #1

Hello,everyone!
How to explore the result of Volume Rendering into models?


(deepmech.maurya) #2

:-1)In scientific visualization and computer graphics, volume
rendering
is a set of techniques used to display a
2D projection of a 3D discretely sampled data set, typically a 3D scalar
field.
2)so what you will see in models is just the 3D image.
3) what else you want to know you should specify and according to
that other modules are available
according to me but i am also new user


(Dr.Xie) #3


The result of CTA with Volume Rendering is much better than any other modules,but the 3D view can not be saved solely.
What i want to know is how to save the 3D view in the proper format,so we can edit the result just like models.


Get 3D output of Volume rendering
(deepmech.maurya) #4

after volume rendering use segmentation>export(the last option)> there are
some format


(Andras Lasso) #5

Volume rendering is a visualization technique. No data is generated that could be exported to models (surface meshes). See detailed explanation in this topic:


(Matt) #6

My understanding is that volumetric rendering is essentially a function (often specific to a tissue and/or imaging modality) which, given a 3D volume (let’s say just a CT volume with voxels with intensity values from 0 to 1), assigns color or intensity/magnitude values and opacity values to each voxel. It is therefore different data than the original 3D volume (although it could be instantly re-created by combining the original volume and the function). When I use the word function I am referring to the display preset in Slicer such as “MR-Default”.

I understand that volume data is inherently different from a surface mesh. However, it would still be useful to be able to export the volumetric rendering as a 3D matrix of intensity values (or color values) with associated opacity values. This would be tremendously useful for a variety of reasons which is why this topic seems to be so popular. I think that many folks are seeing some potential in the Slicer volumetric segmentation module and they want to export some of this secret sauce for use in their own applications/projects.

Is there any way to do this using Slicer?


(Andras Lasso) #7

By burning in looked-up RGBA values into the voxel array you would remove a trivial look-up step, but you would make the data unusable for rendering, as you would lose ability to estimate surface normal from voxel gradient. You could save gradient in a separate volume but then you would end up with a more complicated rendering task overall, increased memory need (about 5x more), and complete inflexibility in how you display your data. This does not seem useful to me and that’s why this kind of data export is not implemented in Slicer (or elsewhere).


(Csaba Pinter) #8

Yes, probably exporting the volume after applying the transfer function would not be too useful.

But maybe we could use some information from volume rendering for simple segmentation. How about allowing the user to specify the desired “color” for thresholding? We could determine the original voxel values from that color (using the transfer function) and a tolerance factor maybe, and do a thresholding to include that interval.


Exporting OBJ with texture from volume rendering
(Andras Lasso) #9

I think live preview in slice views in Threshold effect already makes threshold setting quite easy. With multi-volume rendering (that has just been merged into VTK master today) we will be able to show a live preview in 3D views, too.


(Andras Lasso) split this topic #10

4 posts were split to a new topic: Convert model to volume rendering