[Paraview] Stream Tracer Problem

[Paul Graham]

Hi Ken,

Thanks for figuring it out.  It's a tremendous help!

So now I know I should have used the transform filter on the data from the
beginning, rather than the transform option in the display properties.
This makes a lot of sense since it saves having to transform each and every
time a new variable is displayed (I feel like a dummy for not doing this
first off, but I am fairly new to Paraview).

Greatly appreciated,

Paul


On 8 November 2013 09:40, Moreland, Kenneth <kmorel at sandia.gov> wrote:

>  Yup, figured it out. There are a couple of problems with the state file
> you sent me.
>
>  First, you have the stream tracer filter connected to the output of the
> glyph filter. It needs to be connected to the calculator (VectorCalc)
> filter. I'm sure that was just a silly mistake.
>
>  Second, your data set is super extremely long. The dimensions are 45 x
> 40 x 98,800. As I said in a previous email, if your data is very skinny (or
> thin), then the point seed for the stream tracer is likely to completely
> miss the data. The line source doesn't seem to be working either. Perhaps
> the cells are so long and thin the cell locator or integrator is not
> operating correctly.
>
>  I see you tried to correct this skinniness by using the scale transform
> in the display properties. This only scaled the data when rendering. The
> underlying data that filters operate on is still really, really skinny. I
> advise to never, never, never use the transform options in the display
> properties. They screw up some other features in ParaView and also lead to
> pretty confusing behavior even when the result is technically "right" (as
> you just experienced). I've advocated in the past in getting rid of this
> feature, but too many people rely on it.
>
>  Anyway, the right thing to do is use the transform filter to adjust the
> scale of the actual data. Once you do that, the data will behave as
> expected. Attached is a screenshot of some successful streamlines.
>
>  -Ken
>
>
>   From: Paul Graham <meteorpaul at gmail.com>
> Date: Thursday, November 7, 2013 2:35 PM
>
> To: Kenneth Moreland <kmorel at sandia.gov>
> Cc: "paraview at paraview.org" <paraview at paraview.org>
> Subject: [EXTERNAL] Re: [Paraview] Stream Tracer Problem
>
>    Hi Ken,
>
>  I have attached a sample of the data to this message along with the saved
> Paraview state.  Hopefully this will help diagnose why it is not working.
>
> Thanks again for your help.
>
>  Paul
>
>
> On 8 November 2013 02:46, Moreland, Kenneth <kmorel at sandia.gov> wrote:
>
>>   Would it be possible to send a small example of your data to the list
>> so we could try it out? If not, could you at least send a screen shot so we
>> could have a look at the mesh? Right now I'm just making blind guesses.
>>
>>  -Ken
>>
>>
>>   From: Paul Graham <meteorpaul at gmail.com>
>> Date: Thursday, November 7, 2013 1:26 AM
>> To: Kenneth Moreland <kmorel at sandia.gov>
>> Cc: "paraview at paraview.org" <paraview at paraview.org>
>> Subject: [EXTERNAL] Re: [Paraview] Stream Tracer Problem
>>
>>    Hi Ken,
>>
>>  Thanks for your suggestions.  I still haven't worked out why it's not
>> working, but I notice that no data is registering in the Stream Tracer
>> filter.  It's mesh is empty - no points or cells - and the bounding
>> information not available.
>>
>> I tried a high density Line Source, as you suggested, as well as
>> increasing the number of seed points within the radial ball of the Point
>> Source but without success.  However, both the Line Source and the Point
>> Source correctly display within the domain of the 3D vector field.
>>
>>  The vectors themselves (from the glyph filter) display correctly.
>>
>>  Paul
>>
>>
>> On 7 November 2013 09:05, Moreland, Kenneth <kmorel at sandia.gov> wrote:
>>
>>>   That is not a lot of detail to go on so I have to guess what the
>>> problem is. It is probably either that the seeds are not intersecting the
>>> mesh or that vectors do not yield good lines.
>>>
>>>  If you mesh is very thin or comprises surface elements, then chances
>>> are all the seed points are outside your mesh. The default point source is
>>> actually a point cloud with randomly selected points within a sphere of a
>>> certain radius. If your mesh is flat, the chance of any seed happening to
>>> hit it are extremely low. Try changing to a line source and see if that
>>> helps.
>>>
>>>  It could be that the vectors your creating are not integrating well.
>>> It could be that the vectors are pointing off of the mesh (which is also
>>> common in thin or flat meshes). Thus it dies before it starts. Or perhaps
>>> it has some other feature that makes it difficult to integrate.
>>>
>>>  -Ken
>>>
>>>   From: Paul Graham <meteorpaul at gmail.com>
>>> Date: Wednesday, November 6, 2013 2:40 PM
>>> To: "paraview at paraview.org" <paraview at paraview.org>
>>> Subject: [EXTERNAL] [Paraview] Stream Tracer Problem
>>>
>>>    Hi Everyone,
>>>
>>> I am unable to display a Stream Tracer and not sure what is going
>>> wrong.  After creating a vector field using the Calculator Filter, I added
>>> the Stream Tracer filter using a point source seed (default setting).  The
>>> point source  origin is displayed but nothing else.  Can anyone help me as
>>> to what I have to do to get the stream lines to show?
>>>
>>>  Thanks in advance,
>>>
>>>  Paul
>>>
>>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.paraview.org/pipermail/paraview/attachments/20131108/c276f947/attachment.htm>