OBJ_IO
Read and Write Routines
Alias OBJ 3D Graphics Files

OBJ_IO is a C++ library which reads or writes some of the 3D graphics information stored in an Alias OBJ file.

Licensing:

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

Languages:

OBJ_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 STLA and other formats.

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

OBJ, a data directory which has some examples of OBJ files.

OBJ_TO_PLY, a C program which reads an OBJ file and writes similar information to a PLY file.

OBJ_TO_TRI_MESH, a MATLAB program which reads an OBJ file and extracts the surface mesh data as a TRI_MESH dataset.

OBJ2OPENGL, a PERL script which converts an OBJ file to a C/C++ include file appropriate for use with OPEN_GL.

PLY_TO_OBJ, a C program which reads a PLY 3D graphics file and writes an equivalent OBJ graphics file.

Reference:

1. http://www.alias.com/eng/index.shtml, The Alias web site.
2. obj_format.txt, some information about the OBJ format.

Source Code:

• obj_io.cpp, the source code.
• obj_io.hpp, the include file.
• obj_io.sh, commands to compile the source code.

Examples and Tests:

• obj_io_prb.cpp, a sample calling program.
• obj_io_prb.sh, commands to compile and run the sample program.
• cube.obj, a simple OBJ file that describes a cube.
• cube_no_normals.obj, an OBJ file describing a cube, without normal vectors, written by OBJ_WRITE.
• cube_normals.obj, an OBJ file describing a cube, including normal vectors, written by OBJ_WRITE.
• obj_io_prb_output.txt, the output file.

List of Routines:

• I4_MAX returns the maximum of two I4's.
• OBJ_FACE_NODE_PRINT prints the node indices for each face.
• OBJ_NORMAL_VECTOR_PRINT prints the normal vectors.
• OBJ_NODE_XYZ_PRINT prints the node coordinates.
• OBJ_SIZE determines sizes of graphics objects in an Alias OBJ file.
• OBJ_SIZE_PRINT prints sizes associated with an OBJ file.
• OBJ_VERTEX_NORMAL_PRINT prints the normal vectors indices per vertex.
• OBJ_WRITE writes graphics information to an Alias OBJ file.
• R8VEC_CROSS_PRODUCT_3D computes the cross product of two R8VEC's in 3D.
• S_LEN_TRIM returns the length of a string to the last nonblank.
• S_WORD_COUNT counts the number of "words" in a string.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

You can go up one level to the C++ source codes.