@Override
 protected void readParameters() throws Exception {
   String s = xr.getXmlData("jvxlFileTitle", null, false, false);
   jvxlFileHeaderBuffer = SB.newS(s);
   xr.toTag("jvxlVolumeData");
   String data = tempDataXml = xr.getXmlData("jvxlVolumeData", null, true, false);
   volumetricOrigin.setT(xr.getXmlPoint(data, "origin"));
   isAngstroms = true;
   readVector(0);
   readVector(1);
   readVector(2);
   line = xr.toTag("jvxlSurfaceSet");
   nSurfaces = parseIntStr(XmlReader.getXmlAttrib(line, "count"));
   Logger.info("jvxl file surfaces: " + nSurfaces);
   Logger.info("using default edge fraction base and range");
   Logger.info("using default color fraction base and range");
   cJvxlEdgeNaN = (char) (edgeFractionBase + edgeFractionRange);
 }
 @Override
 protected void gotoData(int n, int nPoints) throws Exception {
   if (n > 0) Logger.info("skipping " + n + " data sets, " + nPoints + " points each");
   vertexDataOnly = jvxlData.vertexDataOnly = (nPoints == 0);
   for (int i = 0; i < n; i++) {
     jvxlSkipData(nPoints, true);
   }
   xr.toTag("jvxlSurface");
   jvxlReadSurfaceInfo();
 }