[vtkusers] VTK6 + Java7 on Mac: offscreen rendering?

Tue Sep 10 13:06:00 EDT 2013

Hi Seb,

thanks for your feedback.

The example was indeed useful: I am now using vtkJoglCanvasComponent (got
current VTK 6.1 from GIT) as my rendering component, and now I am rendering
my 3D view through JOGL, after loading a bunch of JARs and native libs.

Rendering seems to work quite fine on Windows (I am testing on this OS
first of all, then I will move to Mac later), and I can see my 3
vtkImagePlaneWidgets in the 3D view. Also, if I programmatically
change vtkImagePlaneWidgets' plane positions or orientations, and then call
Render() on my vtkJoglCanvasComponent, the 3D view is updating fine.

On the other side, if I try to interact with the widgets in the 3D view
through the mouse, my Java application immediately and completely freezes,
and the CPU goes up to 25%.

Can you guess what is causing this behavior? Is interaction with widgets
supposed to work when using JOGL?

I have not tested this, but I have the impression that the application
freezes when the widget's native code calls "this->Interactor->Render();".
Will this call be somehow "intercepted" by JOGL, and become equivalent to
calling Render() on the vtkJoglCanvasComponent (which, on the other side,
seems to work fine)?

Thanks again for your feedback: this path seems really promising, and may
open a whole new world with using VTK from Java.

Regards,

Marco

On Mon, Sep 9, 2013 at 5:33 PM, Sebastien Jourdain <
sebastien.jourdain at kitware.com> wrote:

> Hi Marco,
>
> you will have to use another class. But you will have the same integration
> capability.
>
> Look at src/VTK/Wrapping/Java/vtk/sample/rendering/JoglConeRendering.java
> for more details.
>
> Seb
>
>
> On Mon, Sep 9, 2013 at 10:37 AM, Marco Sambin <m.sambin at gmail.com> wrote:
>
>> Hi Seb,
>>
>> this is great news, and I will give it a try!
>> One question: will I be able to keep using vtkCanvas as a Java panel
>> class, or rather shall I move to something different?
>> Thanks again for your feedback.
>>
>> Best regards,
>>
>> Marco Sambin
>>
>>
>>
>> On Mon, Sep 9, 2013 at 2:45 PM, Sebastien Jourdain <
>> sebastien.jourdain at kitware.com> wrote:
>>
>>> Hi Marco,
>>>
>>> you won't be able to rely on offscreen rendering on Mac to properly
>>> handle the issue you are trying to overcome.
>>>
>>> Although, a couple of weeks ago, I've pushed a new set of classes that
>>> works on Mac OS X and Java7 (and on the other of the platforms).
>>> Those classes rely on JOGL to do the rendering. So if adding JOGL as a
>>> dependency is not an issue, you can directly use those.
>>>
>>> For that you will need to get VTK/master from git and when you build
>>> VTK, you will have to turn ON that component. Moreover if you already
>>> download JOGL/GLUGEN using maven, CMake should find the appropriate jars
>>> for you.
>>> Otherwise you will need to specify their paths.
>>>
>>> Here is the dependency for Maven.
>>>
>>> +                <dependency>
>>> +                    <groupId>org.jogamp.jogl</groupId>
>>> +                    <artifactId>jogl-all-main</artifactId>
>>> +                    <version>2.0.2</version>
>>> +                </dependency>
>>> +                <dependency>
>>> +                    <groupId>org.jogamp.gluegen</groupId>
>>> +                    <artifactId>gluegen-rt-main</artifactId>
>>> +                    <version>2.0.2</version>
>>> +                </dependency>
>>>
>>> Hope that could help you,
>>>
>>> Seb
>>>
>>>
>>>
>>> On Mon, Sep 9, 2013 at 7:22 AM, Marco Sambin <m.sambin at gmail.com> wrote:
>>>
>>>> Dear VTKers,
>>>>
>>>> I am developing a VTK 6-based Java application, and I am making some
>>>> efforts to make it compatible with Mac OS X as well.
>>>>
>>>> I know that the jawt embedding currently supported by Java 7 on Mac
>>>> (which is CALayer-based) does not work with VTK 6 (nor with previous VTK
>>>> versions), but there are several portions of my application which do not
>>>> use direct drawing by VTK classes to Java panels (i.e., do not use jawt),
>>>> hence will work fine on Mac + Java 7 as well.
>>>>
>>>> Now, for the portions of my application where VTK classes need to
>>>> actually "draw", my question is: will offscreen rendering work on Mac? The
>>>> basic idea would be to grab the output of the offscreen rendering, convert
>>>> it to a Java-compatible image, and draw it to a Java panel. I know this
>>>> will be a significant performance penalty, but my requirements in this
>>>> moment are not so strict or demanding under this point of view.
>>>>
>>>> In particular, I have a vtkCanvas-derived panel, where I display some
>>>> planes in 3D (actually, they are vtkImagePlaneWidgets, but I am mainly
>>>> interested in the "display" functionality, not in the interactivity of the
>>>> widget with the user). Will it be sufficient to call
>>>> myVtkCanvas.GetRenderWindow().SetOffScreenRendering(1) to obtain offscreen
>>>> rendering on my Mac? Or it is more complicated than that?
>>>>
>>>> Currently, calling just
>>>> myVtkCanvas.GetRenderWindow().SetOffScreenRendering(1), I am obtaining a
>>>> crash in the OpenGL library when running my application on the Mac.
>>>>
>>>> Thanks in advance for your feedback.
>>>>
>>>> Best regards,
>>>>
>>>> Marco
>>>>
>>>>
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>>
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