OBJ_IO
Read and Write Routines
Alias OBJ 3D Graphics Files

OBJ_IO is a FORTRAN90 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_SURFACE, a MATLAB program which reads an OBJ file and extracts the surface mesh data as a TRI_SURFACE dataset.

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

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.

Source Code:

• obj_io.f90, the source code.

Examples and Tests:

• obj_io_test.f90, a sample calling 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_test.txt, the output file.

List of Routines:

• CH_CAP capitalizes a single character.
• CH_EQI is a case insensitive comparison of two characters for equality.
• CH_IS_CONTROL is TRUE if C is a control character.
• CH_TO_DIGIT returns the integer value of a base 10 digit.
• GET_UNIT returns a free FORTRAN unit number.
• 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_READ reads graphics information from a Wavefront OBJ file.
• 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_3D computes the cross product of two vectors in 3D.
• S_BLANK_DELETE removes blanks from a string, left justifying the remainder.
• S_BLANKS_DELETE replaces consecutive blanks by one blank.
• S_CAT concatenates two strings to make a third string.
• S_CONTROL_BLANK replaces control characters with blanks.
• S_EQI is a case insensitive comparison of two strings for equality.
• S_TO_I4 reads an I4 from a string.
• S_TO_R8 reads an R8 from a string.
• TIMESTAMP prints the current YMDHMS date as a time stamp.
• WORD_NEXT_READ "reads" words from a string, one at a time.

You can go up one level to the FORTRAN90 source codes.