Writes out triangular cell sets as binary STL files.
module write_stl< build_dir="iac_proj/writestl",
src_file="writestl.cxx",
out_hdr_file="gen.hxx",
out_src_file="gen.cxx",
libdeps="FLD",
cxx_hdr_files="fld/Xfld.h">
{
cxxmethod+req update<status=1>(
filename+read+req,
trigger+read+req+notify,
in+read,
.err+write,
.err_str+write);
string filename<export=2,NEportLevels={2,0}>;
int trigger<export=2,NEportLevels={2,0}>;
Mesh &in<export=2,NEportLevels={2,0}>;
int err<export=2,NEportLevels={0,2}> = 0;
string err_str<export=2,NEportLevels={0,2}> = "";
};
The write_stl module writes binary STL(Stereo Lithography) files based upon the data contained in triangular cell sets. The input to the module is a standard Mesh object which should contain one or more cell sets of type "Tri". If the Mesh contains more than one cell set then only the last cell set will be written to the STL file. The triangular cell set is written to file according to the binary STL format. Facet normal vectors are calculated and written to file. The attribute block is not used and null data is written to it.
It is intended that the write_stl module should be used to write the output of a visualization module to a STL file. Many visualization modules, such as isosurface, output field data containing a single triangular cell set. By using this module these results can be conviently output as an STL file for further manipulation. As most of these visualization modules output only a single cell set the way that the write_stl module treats multiple cell sets should not be a problem. Naturally, this module can be used with any Meshes that contain suitable triangular cell sets. However it is most easily used when combined with visualization modules, such as isosurface. An example of this is shown in WriteSTLEg.
&in
Reference to the Mesh that contains the triangular cell set that is to be written to the STL file. If no triangular cell sets are present then an error message will be given. If multiple triangular cell sets are present then the last cell set only will be written to the STL file.
filename
The name of the file that should be written to. This parameter is of type string. Note that if an existing file is specified the module will not warn that the original file is being overwritten. If error-checking of this type is required then it should be provided at a higher level.
trigger
This parameter is used to notify the module that the output file should be written. The parameter is of type int. Whenever the value of this parameter is set the write_stl module is notified. This causes the module to read the current input mesh and create the corresponding STL file. If this parameter can be connected to a UIButton component to create a simple user interface.
err
err_str
These two parameters control the output of error messages. The err parameter is an int value that is set to 1 whenever an error occurs. This parameter can therefore be used to control the display of error messages in the user interface. The err_str parameter is a string value that is used to return error messages from the write_stl module. The writeSTL user macro shows now it is possible to use the state of the err parameter to control the display of the text in the err_str parameter.
The low-level write_stl module is used in the User Macro writeSTL. This can be used as is in applications. An example of how it can be used is shown in WriteSTLEg.
An example application WriteSTLEg is provided, which calculates an isosurface of the hydrogen volume data. The resulting mesh can be written to a user specified STL file. This file can subsequently be read by either the IAC ReadSLPSTL project or other programs that use the binary STL file format.
iac_proj/writestl/wrstmods.v contains the write_stl module V definition.
The low-level WriteSTLMods library containing the module write_stl does not specify a process. By default the express process will be used.
Ian Curington
Andrew Dodd
International AVS Centre Manchester Visualization Centre Manchester Computing University of Manchester Oxford Road Manchester United Kingdom M13 9PL
write_stl, writeSTL, WriteSTLEg