[vtkusers] Overlaying a slice on top of a vtk volume

[Anja Ende]

Hi David,

Thanks for the quick reply!

So with this I can just create a vtkImageActor, set my volume as an
input and then use the SetDisplayExtent to show the relevant slice.
This actor, I guess just gets added to the renderer. Thanks for the
top on adding the vtkPlane to the volume mapper. Just a couple of
questions:

- Is there something that I will have to to ensure that the volume is
behind the image actor?
- Also, I am not very experienced with using the vtkImageMapToColors.
So, I have a grayscale MR slice and I would like to display it the way
it is. I guess just scaling the values to [0, 255] would do the
trick... Could you give me some further pointer on how I can go about
doing this?

Thanks again for your help.

Anja


On 8 February 2010 22:20, David Gobbi <david.gobbi at gmail.com> wrote:
> As long as an orthogonal slice is okay (i.e. along the x, y, or z
> direction), just use vtkImageActor and use the SetDisplayExtent method
> of the image actor to set the slice that you want to display.
> ImageActor expects RGB (or RGBA) data, so you will have to pass the
> image through vtkImageMapToColors (with an appropriate vtkLookupTable)
> before putting it into the image actor.
>
> You will probably also have to add a vtkPlane to the VolumeMapper as a
> clipping plane, so that you can clip away the part of the volume that
> would otherwise be in front of the image.  The clipping plane must be
> set to coincide with the image slice shown on the image actor.
>
>  David
>
>
> On Mon, Feb 8, 2010 at 2:56 PM, Anja Ende <anja.ende at googlemail.com> wrote:
>> Hello everyone,
>>
>> I am going a simple volume rendering with vtkVolume and it seems to
>> all work ok. One thing I want to do is overlay a slice on top of this
>> rendered volume. For doing the volume rendering, I used David Gobbi's
>> Medical4.cxx example and it works quite well.
>>
>> So, I want to create a small animation where I render the volume and
>> render some particular slice (vtkImageData) on top of it. What would
>> be the best way to go about doing this?
>>
>> Cheers,
>>
>> Anja
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-- 
Cheers,

Anja