[vtkusers] Transparency issue beetween actors

Jothy jothybasu at gmail.com
Thu Aug 19 09:45:28 EDT 2010


I thought you are using vtkRenderWindow and vtkRenderer for the
visualization. After seeing your code I realized you are using
vtkImageViewer2. vtkImageViewer2 is a convenient class which bundles all the
necessary classes for the visualization.

If you rotate the objects rendered in the viewer, you should be able to see
the circle, because it must be behind the image that's why you are not
seeing it.

To overcome this problem either use separate vtkRenderWindow+vtkRenderer
with coincidentTopologyToPolygonOffset in mapper or set appropriate offset
to the circle actor (in Z direction).

Hope this helps!

Jothy

On Thu, Aug 19, 2010 at 2:14 PM, Bertrand de Boisdeffre <
bertrand.boisdeffre at gmail.com> wrote:

> The language what i use is C#. I can't call a class static method, with an
> object of this class. The call of these methods have to be like this :
>
> ClassName.StaticMethod();
>
> // this code is wrong
> Class classObject = new Class();
> classObject.StaticMethod();
>
>
> 2010/8/19 Jothy <jothybasu at gmail.com>
>
>> What about setting
>> sliceMapper->SetSetResolveCoincidentTopologyToPolygonOffset() ?
>>
>> Jothy
>>
>>
>> On Thu, Aug 19, 2010 at 11:03 AM, Bertrand de Boisdeffre <
>> bertrand.boisdeffre at gmail.com> wrote:
>>
>>>  I tried this code (maybe wrong):
>>>
>>> vtkPolyDataMapper.SetSetResolveCoincidentTopologyToPolygonOffset()
>>> slicemapper= vtkPolyDataMapper.New();
>>> sliceMapper.SetInput( "");
>>> ...
>>>
>>> but it doesn't resolve my problem. However, this method is static and i
>>> don't know if i have to call it as I do in my code.
>>>
>>> 2010/8/19 Jothy <jothybasu at gmail.com>
>>>
>>> Try setting .SetResolveCoincidentTopologyToPolygonOffset in the
>>>> vtkPolyDataMapper.
>>>>
>>>>
>>>> Jothy
>>>>
>>>> On Thu, Aug 19, 2010 at 9:18 AM, Bertrand de Boisdeffre <
>>>> bertrand.boisdeffre at gmail.com> wrote:
>>>>
>>>>> Hi,
>>>>> I have an issue about actors transparency. I try to display in a 3D
>>>>> scene, some volumes ( vtkPolyData are the source) intersected by a plane
>>>>> which has an image texture.
>>>>> I manage to display correctly all my actors, but when i set an actor
>>>>> opacity to a value different to 1, if this actor is located beetween the
>>>>> camera and the "image plane", it diseapears.
>>>>>
>>>>> Here is my code to built my "image plane":
>>>>>
>>>>>  vtkActor sliceActor = new vtkActor();
>>>>>             // ImageSlice full path
>>>>>             string imageFullPath =
>>>>> System.IO.Path.GetFullPath(xmlBinding.GetSlice(XmlSlice.SliceRef).pictureRelativePathWithOverlays);
>>>>>
>>>>>
>>>>>             // Read the file
>>>>>             vtkPNGReader imageReader = new vtkPNGReader();
>>>>>             if(System.IO.File.Exists(imageFullPath))
>>>>>             {
>>>>>                 imageReader.SetFileName(imageFullPath);
>>>>>                 imageReader.Update();
>>>>>
>>>>>  vtkPlaneSource plane = vtkPlaneSource.New();
>>>>>                 plane.SetOrigin(0, 0, 0);
>>>>>
>>>>>                 if (XmlSlice.SliceRef != 0)
>>>>>                 {
>>>>>                     plane.SetPoint1(511 * THOutline.PIXELSIZE, 0, 0);
>>>>>                     plane.SetPoint2(0, 0, -674 * THOutline.PIXELSIZE);
>>>>>                     plane.SetXResolution(1);
>>>>>                     plane.SetYResolution(1);
>>>>>
>>>>>                 }
>>>>>                 else
>>>>>                 {
>>>>>                     plane.SetPoint1(0, 511 * THOutline.PIXELSIZE, 0);
>>>>>                     plane.SetPoint2(0, 0, -674 * THOutline.PIXELSIZE);
>>>>>                     plane.SetXResolution(1);
>>>>>                     plane.SetYResolution(1);
>>>>>                 }
>>>>>                 plane.SetCenter(XmlSlice.SlicePos.Xum,
>>>>> XmlSlice.SlicePos.Yum, XmlSlice.SlicePos.Zum + (674 * THOutline.PIXELSIZE /
>>>>> 2 - this.GetFocalPositionImageTopUm()));
>>>>>
>>>>>                 vtkPolyDataMapper sliceMapper =
>>>>> vtkPolyDataMapper.New();
>>>>>                 sliceMapper.SetInput(plane.GetOutput());
>>>>>
>>>>>
>>>>>
>>>>>                 sliceActor.SetMapper(sliceMapper);
>>>>>
>>>>>                 vtkTexture sliceTexture = vtkTexture.New();
>>>>>                 sliceTexture.SetInput(imageReader.GetOutput());
>>>>>                 sliceTexture.InterpolateOn();
>>>>>                 sliceTexture.SetQualityTo32Bit();
>>>>>
>>>>>                 sliceActor.SetTexture(sliceTexture);
>>>>>
>>>>>                 }
>>>>>             return sliceActor;
>>>>>
>>>>> So the image is correctly display, but if i had an a other actor as in
>>>>> this schema (top view):
>>>>>
>>>>>                            _________                                 :
>>>>> image slice actor
>>>>>
>>>>>                          00000000000                               :
>>>>> "volume actor"
>>>>>
>>>>>
>>>>>                                    -
>>>>>                                   |
>>>>> |                                       : camera
>>>>>
>>>>>
>>>>> if volume actor opacity = 1, all work well.
>>>>> if volume actor opacity != 1 =>
>>>>>
>>>>>                             _________       : image slice actor
>>>>>
>>>>>
>>>>>                            0               00   : "volume actor"
>>>>>
>>>>>
>>>>>                                    -
>>>>>                                   | |               : camera
>>>>>
>>>>>
>>>>> I make some researches on web, and i found (maybe) a solution : using
>>>>> "vtkDephtSortPolyData but I am not sure to know how it works ( and maybe it
>>>>> is not the solution) .
>>>>>
>>>>> So i ask your help.
>>>>>
>>>>> Best Regards,
>>>>> --
>>>>> Bertrand de Boisdeffre
>>>>> Etudiant 2A  SICOM Phelma Grenoble-INP
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Powered by www.kitware.com
>>>>>
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>>>>>
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>>>>>
>>>>>
>>>>
>>>
>>>
>>> --
>>> Bertrand de Boisdeffre
>>> Etudiant 2A  SICOM Phelma Grenoble-INP
>>>
>>>
>>
>
>
> --
> Bertrand de Boisdeffre
> Etudiant 2A  SICOM Phelma Grenoble-INP
>
>
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