<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">2016-08-11 13:26 GMT+02:00 Elvis Stansvik <span dir="ltr"><<a href="mailto:elvis.stansvik@orexplore.com" target="_blank">elvis.stansvik@orexplore.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><span class="">2016-08-11 11:37 GMT+02:00 Elvis Stansvik <span dir="ltr"><<a href="mailto:elvis.stansvik@orexplore.com" target="_blank">elvis.stansvik@orexplore.com</a>></span><wbr>:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><span>2016-08-11 11:18 GMT+02:00 Elvis Stansvik <span dir="ltr"><<a href="mailto:elvis.stansvik@orexplore.com" target="_blank">elvis.stansvik@orexplore.com</a>></span><wbr>:<br></span><span><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div><div><div>Hi all,<br><br></div>I'm wrestling with a volume rendering problem.<br><br></div>I've set up a very basic pipeline that just renders a volume.<br><br></div><div>As source it uses a custom reader I wrote that loads a volume from a HDF5 dataset (float).<br><br>It seemed to be working fine with the volume I had been testing with (see attached works_fine.png), which was a 120x120x2000. In addition to the the rendering itself, the screenshot shows a histogram plot I was using for debugging, as well as some editor controls I use to modify the color/opacity transfer function.<br><br></div><div>I then tested with another volume which is larger (300x300x5000), but apart from that has pretty much the same characteristic for its scalar values as the first one, and all of a sudden I don't see anything. See the attached not_working.png, which shows the setup using the problematic volume.<br><br></div><div>As you can in the histogram, there's a lot of voxel values roughly around 1, much like in the first volume, so I would expect that with the same transfer functions (black color, and an opacity ramp from 0.0,0.0 up to 5.0,1.0), I should see _something_.<br><br></div><div>I'm pretty sure I'm missing something basic here, but does anyone have an idea why I get the expected rendering with my smaller volume, but not with the bigger one?<br><br></div><div>Thanks a lot for any advice!<span><font color="#888888"><br></font></span></div></div></blockquote><div><br></div></span><div>Sorry, shortly after sending this I think I got one step closer to an explanation. The file from which I load this second, larger, volume is actually a concatenation of several files, and I just tried loading one of the files separately and it worked fine (the rendering looks as expected). So something is probably wrong in the script I use for concatenating HDF5 files. I'll do some digging there.<span><font color="#888888"><br></font></span></div></div></div></div></blockquote><div><br></div></span><div>There seems to be nothing wrong with the concatenation script I'm using. I've now tried creating smaller volumes by not concatenating the full set of files, and up until a resulting volume of around ~2500x300x300 it works okay, but if I extend the volume more than that, the rendering fails like described previously. It's quite strange :/ And I don't think I'm hitting some out-of-memory condition inside VTK, since it normally prints nice errors and crashes if that happens.<span class=""><font color="#888888"><br></font></span></div></div></div></div></blockquote><div><br></div><div>I'm beginning to think that maybe I'm running out of graphics memory? Could this be a symptom of that?<br><br></div><div>I've now created a minimal test case, and would very much appreciate if someone could try it out to see if they get the same problem:<br><br></div><div>Download<br><br> <a href="https://drive.google.com/open?id=0B1a2u6qVxaL7M1B6bFhreE1RQW8">https://drive.google.com/open?id=0B1a2u6qVxaL7M1B6bFhreE1RQW8</a><br><br></div><div>and extract the .tar archive (162 MB since it includes two volumes). Then<br><br></div><div> cmake .<br></div><div> make<br></div><div> ./voltest working.hdf5<br></div><div> ./voltest not_working.hdf5<br><br></div><div>For me, rendering of working.hdf5 works, but not rendering of not_working.hdf5. Is that the case also for you?<br><br></div><div>The only difference between the two volumes is that not_working.hdf5 is slightly larger than working.hdf5 (2500 voxels high vs 2000). Apart from that they were both created in the same way.<br><br></div><div>Thanks a lot in advance,<br></div><div>Elvis<br><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div><span class=""><font color="#888888"><br></font></span></div><span class=""><font color="#888888"><div>Elvis<br></div></font></span><span class=""><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div><span><font color="#888888"><br></font></span></div><span><font color="#888888"><div>Elvis<br></div></font></span><span><div> <br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div><span><font color="#888888"><br></font></span></div><span><font color="#888888"><div>Elvis<br></div></font></span><div><br></div><div>PS. If you're confused by the range of the vtkAxisActor that you see in the screenshots, when comparing to the the volume sizes I stated above, it's because my custom render currently hardcodes the spacing to 0.2. DS.<br></div></div>
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