TRI_SURFACE_TO_PLY
Convert data from TRI_SURFACE to PLY format

TRI_SURFACE_TO_PLY is a MATLAB program which converts data describing a triangular mesh of a 3D surface, and reformats it into a data structure suitable for storage as a PLY file.

A TRI_SURFACE or triangulated mesh surface, is described by a pair of arrays:

• a node coordinate array containing the coordinates of nodes;
• a triangle node array containing triples of the indices of the nodes used to form each triangle;

A PLY file contains a sophisticated data structure describing a polygonal surface. A triangulated mesh is a very simply case of such a surface; a PLY file can also describe a mesh surface involving higher order polygons, and it can contain auxilliary information about normal vectors and so on.

Author:

The files PLY_WRITE.M and TRI_SURFACE_TO_PLY were created by Pascal Getreuer.

Related Data and Programs:

BEZIER_SURFACE_DISPLAY is a MATLAB program which reads two files defining a Bezier surface and displays it.

FEM_BASIS_T3_DISPLAY is a MATLAB program which displays a basis function associated with a linear triangle ("T3") mesh.

FEM_BASIS_T6_DISPLAY is a MATLAB program which reads a quadratic triangle mesh and displays any associated basis function.

PLY is a data directory which contains a description and examples of PLY files.

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

PLY_TO_TRI_SURFACE is a MATLAB program which can read a PLY file, extract the polygonal surface information, and return it as a TRI_SURFACE dataset.

POLYGONAL_SURFACE is a data directory which contains examples of polygonal surface files.

STLA_DISPLAY is a MATLAB program which reads an ASCII STL file and displays it.

TRI_SURFACE is a data directory which contains examples of TRI_SURFACE files.

TRI_SURFACE_DISPLAY is a MATLAB program which can display a TRI_SURFACE.

TRI_SURFACE_IO, a MATLAB library which reads and writes the 3D graphics information in a TRI_SURFACE file;

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

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

TRIANGULATION_DISPLAY_OPEN_GL is a C++ program which reads files defining a triangulation and displays an image using Open GL.

Usage:

ply_data = tri_surface_to_ply ( node_xyz, triangle_node )

reads the node coordinate and triangle node arrays for a TRI_SURFACE structure and writes out a data structure suitable for storage as a PLY file.

Source Code:

• i4mat_transpose_print_some.m, prints some of the transpose of an I4MAT.
• ply_write.m, writes a PLY data structure out to a PLY file.
• r8mat_transpose_print_some.m, prints some of the transpose of an R8MAT.
• s_len_trim.m returns the length of a string to the last nonblank.
• timestamp.m prints the current YMDHMS date as a time stamp.
• tri_surface_to_ply.m converts TRI_SURFACE data to PLY data.

Examples and Tests:

• tri_surface_to_ply_test.m runs all the tests.
• tri_surface_to_ply_test01.m sets up a TRI_SURFACE data for a pyramid, displays it, converts it to a PLY format and writes it to a PLY file.
• pyramid.png a PNG image of MATLAB's display of the TRI_SURFACE data.
• pyramid.ply the PLY file created by the test.
• tri_surface_to_ply_test_output.txt output from the tests.

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