[vtkusers] rendering a series of BMP images - revisited

[Prathamesh Kulkarni]

They are gary-scale images. Hence I don't use the color transfer function.
Is this correct? I increased the number of files from 5 to 20 and now it
shows me a volume but with intermediate slices blanked. I think this is a
problem of the opacity function, and I am trying to learn how to use it.
Please let me know if there is any example for it.

Thanks,
Prathamesh

On Mon, Nov 29, 2010 at 1:02 PM, David Gobbi <david.gobbi at gmail.com> wrote:

> Hi Prathamesh,
>
> The range is set by SetDataExtent(), which you do.
>
> But there are several unusual things about your application that you don't
> explain in your email.
> - Are the BMP files RGB or are they greyscale?
> - Did you mean to make a vtkColorTransferFunction for your volume?
> - Why only five slices?
>
>   - David
>
> On Mon, Nov 29, 2010 at 11:57 AM, Prathamesh Kulkarni <
> prathameshmkulkarni at gmail.com> wrote:
>
>> For that I used the SetFilePrefix() and SetFilePattern. Is there any other
>> way of setting the range of files?
>>
>> - Prathamesh
>>
>>
>> On Mon, Nov 29, 2010 at 12:50 PM, Darshan Pai <darshanpai at gmail.com>wrote:
>>
>>> You probably need to set the range of the files
>>>
>>> On Mon, Nov 29, 2010 at 11:36 AM, Prathamesh Kulkarni <
>>> prathameshmkulkarni at gmail.com> wrote:
>>>
>>>>
>>>> Hello,
>>>>
>>>> I am trying to render a series of BMP images as a volume using Ray
>>>> Casting in vtk. However, what I see is only a single slice of image.
>>>>
>>>> Please point me out to where I am doing a mistake. My code is attached
>>>> below.
>>>>
>>>>
>>>>
>>>> #................................................................................................#
>>>>
>>>> import vtk
>>>> from vtk import *
>>>>
>>>> bmp_reader = vtk.vtkBMPReader()
>>>>
>>>> bmp_reader.SetFilePrefix('../sampleData/sample_')
>>>> bmp_reader.SetFilePattern('%s%d.bmp')
>>>>
>>>> #print bmp_reader
>>>>
>>>> height = 512
>>>> width = 496
>>>> depth = 5
>>>>
>>>> #this is default behaviour anyways..
>>>> bmp_reader.SetFileNameSliceOffset(1)
>>>> bmp_reader.SetFileNameSliceSpacing(1)
>>>>
>>>> #bmp_reader.SetNumberOfScalarComponents(3)
>>>> bmp_reader.SetDataSpacing(1, 1, 1)
>>>> bmp_reader.SetDataOrigin(0, 0, 0)
>>>> bmp_reader.SetDataExtent(0, width-1, 0, height-1, 0, depth-1)
>>>> bmp_reader.SetDataScalarTypeToUnsignedChar()
>>>>
>>>> alpha_channel_function = vtk.vtkPiecewiseFunction()
>>>> alpha_channel_function.AddPoint(20, 0.1)
>>>> alpha_channel_function.AddPoint(100, 1.0)
>>>>
>>>> volume_property = vtk.vtkVolumeProperty()
>>>> volume_property.SetScalarOpacity(alpha_channel_function)
>>>>
>>>> composite_function = vtk.vtkVolumeRayCastCompositeFunction()
>>>>  #volume_mapper = vtk.vtkVolumeRayCastMapper()
>>>> volume_mapper = vtk.vtkFixedPointVolumeRayCastMapper()
>>>>
>>>> #volume_mapper.SetVolumeRayCastFunction(composite_function)
>>>> volume_mapper.SetInput(bmp_reader.GetOutput())
>>>>
>>>> volume = vtk.vtkVolume()
>>>> volume.SetMapper(volume_mapper)
>>>> volume.SetProperty(volume_property)
>>>>
>>>> renderer = vtk.vtkRenderer()
>>>> render_window = vtk.vtkRenderWindow()
>>>> render_window_interactor = vtk.vtkRenderWindowInteractor()
>>>>
>>>> render_window.AddRenderer(renderer)
>>>> render_window_interactor.SetRenderWindow(render_window)
>>>>
>>>> renderer.AddVolume(volume)
>>>> renderer.SetBackground(1, 1, 1)
>>>> render_window.SetSize(500, 500)
>>>>
>>>> render_window_interactor.Initialize()
>>>> render_window.Render()
>>>> render_window_interactor.Start()
>>>>
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>>>
>>
>> _______________________________________________
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>>
>> Visit other Kitware open-source projects at
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>> Please keep messages on-topic and check the VTK FAQ at:
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