STLA_IO
Read and Write Routines
ASCII STL 3D Graphics Files

STLA_IO is a MATLAB library which includes routines to read or write the 3D graphics information stored in an ASCII STL (stereolithography) file.

Especially if you are reading large ASCII STL files, you might want to consider the STLA_SIZE_FAST and STLA_READ_FAST routines, provided by Bill Seufzer of NASA Langley. These will run more quickly in MATLAB than the routines STLA_SIZE and STLA_READ.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

STLA_IO is available in a C++ version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

IVCON, a C++ program which can convert graphics information between ASCII STL and other formats.

IVREAD, a FORTRAN90 program which can convert graphics information between ASCII STL and other formats.

STLA, a data directory which contains some examples of ASCII STL files.

STLA_DISPLAY, a MATLAB program which can read an ASCII STL file and display it on the screen.

STLA_TO_TRI_SURFACE, a MATLAB program which reads an ASCII STL file and extracts the surface mesh data as a TRI_SURFACE dataset.

TRI_SURFACE_TO_STLA, a MATLAB program which reads a TRI_SURFACE dataset and extracts the surface mesh data as an ASCII STL file.

Reference:

1. 3D Systems, Inc,
   Stereolithography Interface Specification,
   October 1989.

Source Code:

• ch_cap.m capitalizes a character.
• ch_eqi.m case-insensitive comparison of two characters.
• ch_is_digit.m is true if a character represents a digit.
• ch_to_digit.m converts a character to the digit it represents.
• r8vec_cross_3d.m computes the cross product of two vectors in 3D.
• s_cat.m concatenates two strings to make a third string.
• s_eqi.m is a case insensitive comparison of two strings for equality.
• s_len_trim.m returns the length of a string to the last nonblank.
• s_to_r8.m reads an R8 from a string.
• stla_check.m checks an ASCII STL file.
• stla_face_node_print.m prints the nodes making up each face in an ASCII STL file.
• stla_face_normal_compute.m computes normal vectors for an ASCII STL file.
• stla_face_normal_print.m prints normal vectors for an ASCII STL file.
• stla_node_xyz_print.m prints the node coordinates.
• stla_read.m reads graphics information from an ASCII STL file.
• stla_read_fast.m reads graphics information from an ASCII STL file; this routine should run much faster than stla_read.
• stla_size.m determines sizes associated with an ASCII STL file.
• stla_size_fast.m determines sizes associated with an ASCII STL file; this routine should run much faster than stla_size.
• stla_size_print.m prints sizes associated with an ASCII STL file.
• stla_write.m writes graphics information to an ASCII STL file.
• timestamp.m prints the current YMDHMS date as a time stamp.
• word_next_read.m "reads" words from a string, one at a time.

Examples and Tests:

• stla_io_test.m, commands to run all the tests.
• stla_io_test01.m, tests STLA_CHECK.
• stla_io_test02.m, tests STLA_SIZE.
• stla_io_test03.m, tests STLA_READ.
• stla_io_test04.m, tests STLA_WRITE.
• stla_io_test05.m, tests STLA_FACE_NORMAL_COMPUTE.
• stla_io_test06.m, calls MATLAB's TRIMESH routine to make an image of an ASCII STL file.
• stla_io_test07.m, compares the time required by STLA_SIZE and STLA_SIZE_FAST.
• stla_io_test08.m, compares the time required by STLA_READ and STLA_READ_FAST.
• cube.stla, a simple ASCII STL file that describes a cube.
• cube_new.stla, an ASCII STL file describing a cube, written by STLA_WRITE.
• cube.png, a PNG image of the cube, create by MATLAB's TRIMESH routine.
• sphere.stla, an ASCII STL file that describes a sphere.
• teapot.stla, an ASCII STL file that describes a teapot.
• stla_io_test_output.txt, the output file.

You can go up one level to the MATLAB source codes.