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

[Elvis Stansvik]

2016-10-26 16:27 GMT+02:00 Alvaro Sanchez <alvaro.sanchez at kitware.com>:
> Hi Elvis,
>
> I found the root cause of this, the noise texture is not being correctly
> sampled in the shader.  I will tag you on the MR once the patch is ready so
> that you can try it out.

That's great news \o/ Thanks a lot Alvaro.

Elvis

>
> Cheers,
>
> On Thu, Oct 20, 2016 at 1:30 AM, Elvis Stansvik
> <elvis.stansvik at orexplore.com> wrote:
>>
>> 2016-10-20 5:46 GMT+02:00 Alvaro Sanchez <alvaro.sanchez at kitware.com>:
>> > I ran your test program and I could reproduce the wood-grain artifacts
>> > you
>> > see.  It seems to me that the jitter noise might need some tweaking.  I
>> > will
>> > try a few things and investigate further, will let you know my findings.
>>
>> Thanks Alvaro.
>>
>> Elvis
>>
>> >
>> >
>> > On Wed, Oct 19, 2016 at 8:07 AM, Elvis Stansvik
>> > <elvis.stansvik at orexplore.com> wrote:
>> >>
>> >> 2016-10-19 14:03 GMT+02:00 Alvaro Sanchez <alvaro.sanchez at kitware.com>:
>> >> > Hi Elvis,
>> >> >
>> >> > thanks for the test case.  Sorry, I did not have time to run it yet
>> >> > but
>> >> > I
>> >> > will have a look at it today.
>> >> >
>> >> > It seems unlikely to me that the small data spacing is affecting
>> >> > jittering.
>> >> > I will come back to you after debugging a bit with your test case.
>> >>
>> >> Alright, no hurry. Thanks a lot for having a look.
>> >>
>> >> Elvis
>> >>
>> >> >
>> >> > Cheers,
>> >> > Alvaro
>> >> >
>> >> > On Wed, Oct 19, 2016 at 1:54 AM, Elvis Stansvik
>> >> > <elvis.stansvik at orexplore.com> wrote:
>> >> >>
>> >> >> 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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>> >> >> >>>
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>> >> >> >>
>> >> >> >>
>> >> >> >>
>> >> >> >> --
>> >> >> >> Alvaro Sanchez
>> >> >> >> Kitware, Inc.
>> >> >> >> Senior R&D Engineer
>> >> >> >> 21 Corporate Drive
>> >> >> >> Clifton Park, NY 12065-8662
>> >> >> >> Phone: 518-881-4901
>> >> >
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > Alvaro Sanchez
>> >> > Kitware, Inc.
>> >> > Senior R&D Engineer
>> >> > 21 Corporate Drive
>> >> > Clifton Park, NY 12065-8662
>> >> > Phone: 518-881-4901
>> >
>> >
>> >
>> >
>> > --
>> > Alvaro Sanchez
>> > Kitware, Inc.
>> > Senior R&D Engineer
>> > 21 Corporate Drive
>> > Clifton Park, NY 12065-8662
>> > Phone: 518-881-4901
>
>
>
>
> --
> Alvaro Sanchez
> Kitware, Inc.
> Senior R&D Engineer
> 21 Corporate Drive
> Clifton Park, NY 12065-8662
> Phone: 518-881-4901