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NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
Hi Katie- > Thanks so much for getting back to me and for trying out my files on > your system. Unfortunately, my network won't allow me to receive > graphical attatchments (don't ask me why) so could you resend the > attatchment either to my personal email or > to this address but as part of a Word document? Thanks so much for all > your help and patience. I've cc'd your other email on this response with the attached image. BTW, I fixed the problem with the display only showing up as a thin column. It was a problem with the projection as I suspected. I now make sure we are in the correct projection before calculating the volume for rendering. The fix is in the latest nightly build. I also noted that your lat/lon points in the netcdf file don't match up with shape of the topography image. The topography image looks like southern Florida (except upside down and backwards), but the lat/lon points put it in a smaller area, just east of Key West (lats from 24.3762 to 24.82356, lons from -81.6238 to -81.17645). It looks like it should go from about 24 to 27 and from -82 to -79 from the topography. Maybe this was just meant to be a sample, but just wanted you to know in case it's not. Don > -----Original Message----- > From: Unidata IDV Support [mailto:address@hidden] > Sent: Wednesday, April 23, 2008 5:47 PM > To: Carbonari, Katie > Cc: address@hidden > Subject: [IDV #WNR-458825]: Problem w/volume rendering > > Hi Katie- > > > Thanks so much for your quick response. > > This one took a little longer. ;-) > > > We have been using the 64 bit version of Java, but we get the same > problems when we run the 32 bit version (of course, we have to use a > smaller data set of 250x250x50). If it's not too much trouble, could you > try to render our data set on your setup? We're using a new machine (a > Mac) and want to be sure that the problem is not with the way ours is > configured. If you could do a volume rendering of the data (lwc) and > send us a screen shot, we'd be very much appreciative. If you're > successful, please let us know what you're using (os, graphics card). > Enclosed is a screen shot of the same data in VAPOR. While VAPOR lacks a > lot of the functions we need (that IDV has), it is giving excellent > results in the volume rendering. Our goal is to get our clouds in IDV to > look as good as the clouds in VAPOR. > > I'm not sure you'll get as good as VAPOR, but I've attached a screen > shot of what I was able to produce. It took a long time because we do > on the fly what VAPOR does when it transforms your netCDF file initially > - put the data into display coordinate space. We do it on the fly > because you can display the data in any projection you want. > > I also ran into the issue with it sometimes producing just a small > column. I think that's an issue with the projection changing when you > display the data. If you set the projection to the data space first > (e.g. display a plan view of qc or something), then I don't think that > will be an issue. I'll look into that more closely when I get a chance. > > My graphics card is an ATI Mobility Radeon X1400 w/ 512 Mb. I am using > the Texture3D. Turning that off made a less pretty display. > For the attached, I set the data range to be 150 to 247 and > I set the transparency to be 50%. The other person who > had the problem with the Texture3D was also using a Mac. He had a > NVIDIA GeForce 8600M GT with 256 Mb RAM. > > Don > > -----Original Message----- > > From: Unidata IDV Support [mailto:address@hidden] > > Sent: Fri 4/18/2008 3:36 PM > > To: Carbonari, Katie > > Cc: address@hidden > > Subject: [IDV #WNR-458825]: Problem w/volume rendering > > > > Hi Katie- > > > > > Hi Don. I have a few more questions concerning volume rendering I > hope you can help me with. > > > > > > First off, a little background. I'm trying to do volume rendering of > lwc (liquid water content, clouds) over terrain. Each file is a netCDF > file (80 meg) that has 1250x1250x50 points of liquid water plus > 1250x1250 of terrain elevation. There are 60 files total to be > visualized (1 file=1min). There are several problems I've been having: > > > > > > 1) Even with 12 gig of memory allocated to IDV, often volume > rendering runs out of memory, even at much courser resolutions. Are > there any parameters I can change that will speed up the volume > rendering? > > > > Does the memory monitor actually show 12 Gb allocated? Are you > > running a 64 bit version of Java? The 32 bit version will only > allocate 2 Gb. > > > > > 2) Sometimes IDV does not use the full 12 gigs allocated to it, but > still takes a very long time to render. Is this just because my data set > is so large? > > > > Volume rendering is very much a hog of memory. To do the volume > > rendering we have to retransform the entire dataset. If these are > > staggered WRF grids, that will be even worse because we need to > destagger them. > > > > > 3) Occasionally, instead of getting the entire volume rendered, only > > > > a small "chimney" will be visualized. It appears to be the full data > > > > set but only over 1/20 of the proper area. Any ideas about what > > > causes this? (Of course, I can't get it to do it now, so I don't > > > have a screen shot to show you) > > > > I hate problems like that. ;-) I can't think of anything off the top > > of my head that would cause that. > > > > > 4) Once the data is fully loaded, I can't seem to make the clouds > > > look like clouds. I want to control the volume to be colored by > > > opacity, not color. If the lwc is below a certain threshold value, I > > > > want those points to be totally transparent (ie, want to be able to > > > see straight to the ground). Any advice on how to control the > > > opacity in this way? (see attached photo of how our clouds currently > > > > look; they are not very good-looking clouds) > > > > The image didn't come across, but here are a couple of suggestions. > > First, use the Visible Range in the display control to set the range > > of the values you want to visualize. Alternatively (or in addition > > to), edit the color table and set the transparency for the range you > > don't want to see to 100% and the values you want to see to 90%. That > > > will make those values you want to see more "cloudy". Transparency is > > > order dependent, so if you have other displays in the View, you'll > > want to use the View->Bring to Front menu on the Volume Control so you > can see the other displays. > > > > > Thank you so much for your time, > > > > Don > > > -----Original Message----- > > > From: Unidata IDV Support [mailto:address@hidden] > > > Sent: Thu 4/17/2008 5:34 PM > > > To: Carbonari, Katie > > > Cc: address@hidden > > > Subject: [IDV #WNR-458825]: Problem w/volume rendering > > > > > > Hi Katie- > > > > > > > Full Name: katie carbonari > > > > Email Address: address@hidden > > > > Organization: northrop grumman > > > > Package Version: 2.5 > > > > Operating System: linux > > > > Hardware: > > > > Description of problem: Hello. I've been trying to do some volume > rendering of clouds in IDV. Isosurface works fine (as you can see in the > attatched picture) but volume rendering gives a gray cube. This gray > cube doesn't change when I change various parameters (color range, > transparency, etc). Any ideas on why this is happening? The 2 pics are > of the same data file, so I don't know why the volume rendering doesn't > give clouds. > > > > > > This is probably a graphics card issue. What is the graphics card > > > you are using? > > > > > > Try the following: > > > > > > - do the volume rendering > > > - bring up the properties for the Volume Rendering control > > > (Edit->Properties menu of the control). > > > - Uncheck the Use Texture 3D property and click the OK button. > > > > > > Does that make your volume rendering appear? > > > > > > Don Murray > > > > > > Ticket Details > > > =================== > > > Ticket ID: WNR-458825 > > > Department: Support IDV > > > Priority: Normal > > > Status: Open > > > > > > > > > > > > > > > > > > > > > > > > Ticket Details > > =================== > > Ticket ID: WNR-458825 > > Department: Support IDV > > Priority: Normal > > Status: Open > > > > > > > > > > > > > Ticket Details > =================== > Ticket ID: WNR-458825 > Department: Support IDV > Priority: Normal > Status: Open > > Ticket Details =================== Ticket ID: WNR-458825 Department: Support IDV Priority: Normal Status: Open
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