[vtk-developers] UseJitteringOn() has no effect in 7.1.0.rc1

[Elvis Stansvik]

2016-10-15 11:16 GMT+02:00 Elvis Stansvik <elvis.stansvik at orexplore.com>:
> 2016-10-14 15:54 GMT+02:00 Alvaro Sanchez <alvaro.sanchez at kitware.com>:
>> Hi Elvis,
>>
>> the mapper uses a vtkPerlinNoise instance to generate the jitter noise and
>> as far as I know there are currently no knobs exposed to tweak the amount of
>> ray perturbation.  Are you using the GL2 backend?  It would also be good to
>> know what features are active along with ray jittering (multiple components,
>> etc.), so if you could provide some sample data or code would be very
>> helpful.
>
> Hi again Alvaro,
>
> Here's a minimal test case including sample data (129 MB):
>
>     https://dl.dropboxusercontent.com/u/22350696/test_grain.tar.gz
>
> Build with:
>
>     cmake .
>     make
>
> and run with:
>
>     ./test_grain rec-0300mm-0400mm.xml
>
> The result should be as in the attached screenshot.

Anyone had time to run my test case? Are you seeing the same thing?

Elvis

>
> Elvis
>
>>
>> Thanks!
>> Alvaro
>>
>> On Fri, Oct 14, 2016 at 3:47 AM, Elvis Stansvik
>> <elvis.stansvik at orexplore.com> wrote:
>>>
>>> Hi all,
>>>
>>> I updated our product to use VTK 7.1.0.rc1, as I was interested in
>>> trying out vtkGPUVolumeRayCastMapper::UseJitteringOn() to get rid of
>>> some woodgrain effects we're suffering from in our volume rendering
>>> (mostly when the volumes are rendered very opaque).
>>>
>>> But turning the option on seems to have little to no effect. This is
>>> the result with the option on:
>>>
>>>     https://dl.dropboxusercontent.com/u/22350696/out.ogv
>>>
>>> It looks about the same to me as it does with the option off.
>>>
>>> Are there any knobs for this option? How does it determine how much to
>>> perturbate the rays?
>>>
>>> Thanks for any advise.
>>>
>>> Elvis
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>>
>>
>>
>> --
>> Alvaro Sanchez
>> Kitware, Inc.
>> Senior R&D Engineer
>> 21 Corporate Drive
>> Clifton Park, NY 12065-8662
>> Phone: 518-881-4901