[yt-users] chombo/orion2 projection issue

[Matthew Turk]

Hi Will,

Could you try doing OffAxisProjection of the field "Ones"?  That
should be a good bell-weather for this type of problem.

-Matt

On Thu, Oct 31, 2013 at 6:19 PM, William Gray <graywilliamj at gmail.com> wrote:
> Hi Nathan,
>
> Thanks for your response. I tried a variety of render options and was unable
> to produce a 'correct' plot.
>
> First, as a sanity check I tried a simple volume rendering just to see if
> that would work, the important calls were:
>
> mi,ma = data.quantities["Extrema"]("Density")[0]
> tf = ColorTransferFunction((np.log10(mi)+1,np.log10(ma)))
> tf.add_layers(5,w=0.02,colormap="spectral")
> cam = pf.h.camera(c,L,W,N,tf,no_ghost=False)
> den = cam.snapshot()
>
> where c is centered on some particle, L is is angular momentum vector of
> said particle, W =[1.5e15,1.5e15,1.5e15] and N is 512. This works and gives
> a nice volume render.
>
> Next I tried:
>
> tf = ProjectionTransferFunction()
> cam = pf.h.camera(c,L,W,N,tf,fields=[field],log_fields,
> [use_log],no_ghost=False)
> den = cam.snapshot()
>
> Which is the same as above except with a different transfer function. This
> gives a blank/black projection image. I also retried both
> off_axis_projection and OffAxisProjectionPlot. Both give blank images, as
> expected.
>
> I am working on a test problem to see if I can reproduce this problem. If I
> get one working I will send it along.
>
> Please let me know if there is some other info that may be of importance and
> if there is something else you want me to try.
>
> -Will
>
>
>
> On Thu, Oct 31, 2013 at 10:57 AM, Nathan Goldbaum <nathan12343 at gmail.com>
> wrote:
>>
>> Hi William,
>>
>> Both OffAxisProjectionPlot and off_axis_projection are just wrappers
>> around yt's volume renderer using the ProjectionTransferFunction.
>>
>> I’m not sure why you’re not getting good data with narrow depths, but you
>> might try again by directly calling the volume renderer.  In any case, if
>> you see the same thing it would give us more clues to figure out what is
>> going wrong.
>>
>> Also, if you have a test dataset that exhibits this behavior and you
>> wouldn’t mind sharing, that would also be useful for us to debug this.
>>
>> -Nathan
>>
>> On October 31, 2013 at 10:52:29 AM, William Gray (graywilliamj at gmail.com)
>> wrote:
>>
>> Hello yt-users,
>>
>> I am having an issue in creating off axis projection plots with short
>> depths in yt. I am looking for disks around particles which necessitates
>> using the off axis projection functionality. What I want to do is create a
>> projection where the depth is the same as or similar to the width of the
>> plot. However, I am finding that unless the depth is orders of magnitude
>> larger than the width I will always create a blank plot (for example, the
>> width is ~100 au, the depth to get a plot has to be ~1000xwidth, I want a
>> plot where the width and depth are ~100 au). I have tried using both
>> off_axis_projection and the OffAxisProjection methods with similar (bad)
>> results.
>>
>> As a comparison, I ran a low resolution FLASH simulation that did not seem
>> to have this problem. I also know that such a plot was possible with ORION2
>> data in the recent past (spring of this year) since a colleague was able
>> produce such a plot. That same script now also fails.
>>
>> Does anyone know of a way around this problem? Has there been any recent
>> changes that broke volume rendering for chombo/orion2 data?
>>
>> Thanks,
>> William Gray
>> _______________________________________________
>> yt-users mailing list
>> yt-users at lists.spacepope.org
>> http://lists.spacepope.org/listinfo.cgi/yt-users-spacepope.org
>
>
>
> _______________________________________________
> yt-users mailing list
> yt-users at lists.spacepope.org
> http://lists.spacepope.org/listinfo.cgi/yt-users-spacepope.org
>