Thanks for the tips Dave and Sean, The particle work is not a primary focus for me at the moment, so I may not get around to testing your suggestions right away. But thanks for making them, they will come in handy when I do get back to that work.
joe. On Feb 9, 2012, at 7:00 AM, David E DeMarle wrote: > I suspect there is a path to achieve this through extract selection > with selection by ids as well. Ids are constant across time steps, > which is how we plot particular elements of interest over time. To > populate the selection list with randomly chosen ids you might need to > resort to the python programmable filter swiss army knife. > > David E DeMarle > Kitware, Inc. > R&D Engineer > 21 Corporate Drive > Clifton Park, NY 12065-8662 > Phone: 518-881-4909 > > > > On Wed, Feb 8, 2012 at 6:28 PM, Williams, Sean J <[email protected]> wrote: >> Well, here's one rather odd way of going about it... >> >> Decide on a probability k to keep a point, which is to say, if you have n >> points, you want k*n glyphs. >> >> In a python programmable filter, create a new variable "mask." For each >> point, seed a random number generator [1] with the grid point ID of the >> point, then generate a float f between 0 and 1 (i.e., the random.random() >> method). If f >= k, set mask to 1 for that point; otherwise, set mask to 0. >> (This works because the random number generator always produces the same >> sequence of numbers for the same seed value, so you'll consistently set the >> mask to the same value for the same point ID.) >> >> After the programmable filter has run, take a threshold of 1 to 1 on the >> mask variable. Then just use a glyph filter with "mask points" off. >> >> -Sean >> >> [1] http://docs.python.org/library/random.html >> ________________________________________ >> From: [email protected] [[email protected]] on >> behalf of joseph insley [[email protected]] >> Sent: Wednesday, February 08, 2012 4:17 PM >> To: David E DeMarle >> Cc: ParaView >> Subject: Re: [Paraview] "pseudo" random glyphs >> >> Thanks, Dave, >> >> That worked great for the case where I have a vtkUnstructeredGrid of tets, >> where the coordinates of the mesh does not change over time. >> >> I also have a case where I have a grid of points (particle data), where the >> coordinates of the points change over time. In this case I'd like to use >> the same particle (grid point) IDs for the glyphs for each time step. Using >> the Resample with Data filter doesn't work in this case, since the >> coordinates of the particles are different for each time step. Do you have >> any other tricks up your sleeve to resolve for this case? >> >> Thanks a bunch, >> joe. >> >> On Feb 8, 2012, at 4:37 PM, David E DeMarle wrote: >> >>> Strike that, I wasn't thinking clearly. >>> >>> Generate the seed points dataset as I said before. >>> Now use that and the TVD as inputs to the probe with Resample with >>> Dataset filter. >>> Then glyph that. >>> >>> David E DeMarle >>> Kitware, Inc. >>> R&D Engineer >>> 21 Corporate Drive >>> Clifton Park, NY 12065-8662 >>> Phone: 518-881-4909 >>> >>> >>> >>> On Wed, Feb 8, 2012 at 5:33 PM, David E DeMarle >>> <[email protected]> wrote: >>>> Not sure if the way the seed points move around over time with time >>>> varying data is a bug or a feature. >>>> >>>> A work around is to use the glyph with custom source filter. >>>> >>>> To make the custom source that you will use for the seed points, glyph >>>> the first time step as you are doing now, but make sure the output >>>> type is points. Save that output as a vtk polydata file. >>>> >>>> Next read that file back in and use it as the source input the glyph >>>> with custom source filter. >>>> >>>> David E DeMarle >>>> Kitware, Inc. >>>> R&D Engineer >>>> 21 Corporate Drive >>>> Clifton Park, NY 12065-8662 >>>> Phone: 518-881-4909 >>>> >>>> >>>> >>>> On Wed, Feb 8, 2012 at 4:56 PM, joseph insley <[email protected]> wrote: >>>>> Hi, >>>>> >>>>> Is there a way to generate pseudo-random glyphs on an unstructured grid >>>>> (or I guess any object for that matter), for time series data? That is, >>>>> randomly select the points to use, but then use the same points for each >>>>> time step. If I understand it correctly, not checking the Random Mode >>>>> box causes paraview to just select the first N points. In my case >>>>> (probably most cases), this concentrates all of the glyphs in one region >>>>> of the mesh. Instead, I would like to randomly distribute the glyphs >>>>> across the mesh, and using the Random Mode for this works fine for a >>>>> single time step. But if I want to animate a time series, I would like >>>>> to show glyphs on the same points for each time time step, rather than >>>>> have the glyphs jump all over the place. Is there currently a way of >>>>> doing this? >>>>> >>>>> Thanks, >>>>> joe. >>>>> _______________________________________________ >>>>> Powered by www.kitware.com >>>>> >>>>> Visit other Kitware open-source projects at >>>>> http://www.kitware.com/opensource/opensource.html >>>>> >>>>> Please keep messages on-topic and check the ParaView Wiki at: >>>>> http://paraview.org/Wiki/ParaView >>>>> >>>>> Follow this link to subscribe/unsubscribe: >>>>> http://www.paraview.org/mailman/listinfo/paraview >> >> _______________________________________________ >> Powered by www.kitware.com >> >> Visit other Kitware open-source projects at >> http://www.kitware.com/opensource/opensource.html >> >> Please keep messages on-topic and check the ParaView Wiki at: >> http://paraview.org/Wiki/ParaView >> >> Follow this link to subscribe/unsubscribe: >> http://www.paraview.org/mailman/listinfo/paraview >> _______________________________________________ >> Powered by www.kitware.com >> >> Visit other Kitware open-source projects at >> http://www.kitware.com/opensource/opensource.html >> >> Please keep messages on-topic and check the ParaView Wiki at: >> http://paraview.org/Wiki/ParaView >> >> Follow this link to subscribe/unsubscribe: >> http://www.paraview.org/mailman/listinfo/paraview _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the ParaView Wiki at: http://paraview.org/Wiki/ParaView Follow this link to subscribe/unsubscribe: http://www.paraview.org/mailman/listinfo/paraview
