PLOT3D is not a self describing format. Therefore VisIt does not know if the file it should read is:

  • 2D or 3D
  • Binary or ASCII
  • Fortran-style (record based or not) or C-style
  • Has Iblanking or not
  • Single block or multiblock
  • Structured or unstructured (unstructured currently not supported due to lack of sample data files)

To get VisIt to read your file, you need to give it hints. You do this with a text file with extension .vp3d, which describes the variant of Plot3D being used, or through the Read options that can be set when opening the file.

As of VisIt 2.10.0, for binary files, VisIt will perform some amount of auto-detection. If auto-detection fails, then VisIt will fall back to settings from '.vp3d' if used, or Read options otherwise. If VisIt doesn't display your data as expected, some of these options may need to be tweaked. Auto-detection will most likely fail for non-record based Fortran binary files.

Please Note: If your single-grid data file has the 'nblocks' field, you will need to tell VisIt it is a 'MultiGrid' file. VisIt will then correctly read 'nblocks' and create single-grid output.

Example .vp3d file

New options were added in VisIt 2.10.0, noted below

# Files:
# Note: the Grid file and Solution file fields do not have to be specified.
# If they do not appear, VisIt will assume that the .vp3d should be replaced
# with ".x" for the grid file and ".q" for the solution file.
# Support for time-series solution files added in VisIt 2.10.0.
# VisIt will look for '*' and '?' wildcards in the solution name
# Time-series example, requesting all time steps
# Time-series example requesting subset of time steps

# Single/Multi Grid.  Single grid will be assumed if no value is specified.
# Options:

# Data encoding, ASCII or Binary  Binary will be assumed if no value is
# specified.
# Options:

# Endianness.  This only applies to BINARY files.  Native endian will
# be assumed if no value is specified.
# Options:

# OBSOLETE, Structured assumed, due to lack of unstructured sample data
# Structured grid vs unstructured grids.  Structured grids will be assumed
# unless stated otherwise.
# Options:

# Iblanking.  No iblanking is assumed unless stated otherwise
# Options:

# 2D vs 3D.  3D will be assumed unless stated otherwise.
# Options:
# 3D

# Precision.  Single precision is assumed unless stated otherwise
# Options:

# Compression.  This only applies to ASCII files.  Some codes compress
# repeated values as 4*1.5 as opposed to 1.5 1.5 1.5 1.5.  It is assumed
# the data is not compressed unless stated otherwise.
# Options:

# C vs Fortran Binary. C-Binary is assumed.
# VisIt 2.10.0, added FORTRAN_BINARY_STREAM, to differentiate between
# record-based (FORTRAN_BINARY) and non record based (FORTRAN_BINARY_STREAM)
# Options:

# Time. Tells VisIt whether or not the 'Time' field in the solution file is accurate.
# If set to '1', VisIt will use this as the 'time' value displayed in plots for time-series data. (Default)
# If set to '0', and this is time-series data, VisIt will attempt to parse the 'time' from the solution file name.

# R, Gamma values (used for computing functions like Temperature, Pressure, Enthalpy, Entropy)
# Defaults are shown.
# R 1.0
# GAMMA 1.4

Read options in gui

PLOT3D ReadOptions1.png PLOT3D ReadOptions2.png

Read options in python

# MDServer must be started in order grab the default Open options for the reader
# Grab the default options
opts = GetDefaultFileOpenOptions("PLOT3D")
# and change a couple of things 
# specify sub-selection of time slices.
opts["Solution (Q) File Name"]  = r"Jespersen.1/???3?"
opts["Solution Time field accurate"] = 0
SetDefaultFileOpenOptions("PLOT3D", opts)

OpenDatabase(data_path("./TaperedCylinder/grid.p3d"), 0, "PLOT3D_1.0")

Or, you can create your own subset of the options:

opts = {'Multi Grid':1, "Solution (Q) File Name":"wbtr.bin"}
SetDefaultFileOpenOptions("PLOT3D", opts)
OpenDatabase(data_path("./WingBodyTail/wbtg.bin"), 0, "PLOT3D_1.0")

Here are the defaults:

>>> opt = GetDefaultFileOpenOptions("PLOT3D")
>>> print opt
{'File Format': 1, 'Double Precision': 0, 'Gamma (used for function calculation)': 1.4, 'IBlanking': 0, 
 'R (used for function calculations)': 1.0, 'Solution () File Name': , 'Big Endian': 1, 
 'Solution Time field accurate': 1, 'Multi Grid': 0, '3D': 1}

'File Format' options: 0 -> ASCII, 1 -> C Binary, 2 -> Fortran Binary, 3-> Fortran Binary stream