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
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