[IDV #SUD-184603]: problem loading polar stereographic data into idv

Hi Randy-

> can you explain what "fast rendering is" and how it is different from having 
> the option turned off.

It turns off checking for data that crosses a projection seam which is an
expensive computation.  If you are displaying your data in the native
projection, there is no need to check.  See:

http://www.unidata.ucar.edu/software/idv/release/nightly/docs/userguide/misc/PerformanceTuning.html#fastrender

for more info. 

Don Murray
> ----- Original Message ----
> From: Unidata IDV Support <address@hidden>
> To: address@hidden
> Cc: address@hidden
> Sent: Tuesday, March 24, 2009 3:03:17 PM
> Subject: [IDV #SUD-184603]: problem loading polar stereographic data into idv
> 
> Randy-
> 
> This is Don.  Jeff and Yuan are both away this week.
> 
> > Katie and I are both working this, thus her response below. To clarify 
> > alittle.
> >
> > 1) run IDV 2.6u2 and load 0.5 deg Global GFS. all raw data and formula 
> > computed loads correctly.
> > 2) run IDV 2.7a1 and load 0.5 deg Global GFS. all raw data loads correctly 
> > but an isosurface of total winds does not display correctly.
> 
> Turn on Fast Rendering and you'll see the other half.  A change was
> made between 2.6 and 2.7 on how projections are handled.  We may
> back out of that eventually, but you should have Fast Rendering turned
> on by default anyway with the grids you are using.
> 
> > We definetly see up to 800% CPU on the activity monitor now as it reads the 
> > data in. Before your email below i thought it was parrallelizing the 
> > formula computations.
> 
> No, just reading and rendering.  We'll look into computations later.
> 
> > Katie will be trying volume rendering next.
> 
> That will be an interesting experiment.
> 
> Don Murray
> >
> >
> > ----- Original Message ----
> > From: northrop grumman <address@hidden>
> > To: address@hidden
> > Sent: Tuesday, March 24, 2009 11:29:42 AM
> > Subject: Re: [IDV #SUD-184603]: problem loading polar stereographic data 
> > into idv
> >
> > Hi there. So we played around with the thread count, using 2, 4, and 8 for 
> > both rendering and data reading. It works fine unless we do an isosurface. 
> > Then, only the left half of the data appears (the right half is missing). 
> > If I visualize the same thing in an older version of IDV, all the data is 
> > there. Also, plan views give us full (global) data but isosurfaces don't 
> > (only half, and no the data is not smushed, it's to the correct scale but 
> > the right half is not appearing). Any ideas of what is causing this? Screen 
> > shot attached so you get a better idea of the issue.
> >
> > Thanks!
> >
> >
> > ----- Original Message ----
> > From: Unidata IDV Support <address@hidden>
> > To: address@hidden
> > Cc: address@hidden
> > Sent: Monday, March 23, 2009 11:38:41 AM
> > Subject: [IDV #SUD-184603]: problem loading polar stereographic data into 
> > idv
> >
> > >
> > > Ok we'll give it a spin. do you think there will be a speed up when 
> > > applying a formula to the data for example calculating the total wind 
> > > from the u and v wind components?
> > >
> >
> > Right we we don't parallelize the formula computations, just the final 
> > display rendering and the remote data reading.
> > We will be looking at doing that in the future though.
> >
> > -Jeff
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: SUD-184603
> > Department: Support IDV
> > Priority: Emergency
> > Status: Closed
> >
> >
> >
> >
> >
> 
> 
> Ticket Details
> ===================
> Ticket ID: SUD-184603
> Department: Support IDV
> Priority: Emergency
> Status: Open
> 
> 
> 
> 
> 


Ticket Details
===================
Ticket ID: SUD-184603
Department: Support IDV
Priority: Emergency
Status: Open