Hello, Attn: Sam Skillman (Matthew thinks you might know a solution) I'm attempting to follow the Simple Volume Rendering recipe given in the cookbook (http://yt-project.org/doc/cookbook/simple_plots.html#Simple_Volume_Rendering). I'm using Ramses simulation output and after consulting Matthew Turk it should be fine, using the bleeding edge version, which I am. My code that fails is: pf = load(header) dd = pf.h.all_data() mi,ma = dd.quantities['Extrema']('Density')[0] tf = ColorTransferFunction((np.log10(mi)+1,np.log10(ma))) tf.add_layers(5,w=0.02) center=pf.domain_center look = [0.0,0.0,-1.0] width = 1.0 res = 512 cam = pf.h.camera(center,look,width,res,tf) cam.snapshot("%s_test_snap.png" % pf, clip_ratio=8.0) #Something fails in the progressbar of all places! I get a series of "Failed to split grids." It fails at snapshot, and at the end of the traceback I find: /data2/albert/ramses/yt-x86_64/src/yt-hg/yt/extern/progressbar/widgets.pyc in update_js(self, pbar) 344 $myPB.progressbar({{value: 0, max: {pbar.maxval:d}}}); 345 }} --> 346 """.format(divid=self.uuid, pbar=pbar) 347 348 ValueError: Unknown format code 'd' for object of type 'float' Any idea how to solve this easily? Possibly a good idea to optionally remove the progressbar in the future? -- Best Regards, Joshua G. Albert