PLY_TO_TRI_SURFACE
Convert data from PLY to TRI_SURFACE format

PLY_TO_TRI_SURFACE is a MATLAB program which reads data from a PLY file describing a polygonal mesh of a 3D surface,and converts it to a pair of arrays describing a triangular mesh or TRI_SURFACE.

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.

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;

Usage:

[ node_xyz, triangle_node] = ply_to_tri_surface ( 'ply_file_name' )

• 'ply_file_name' is the name of the PLY file to be read;
• node_xyz is the node coordinate array;
• triangle_node is the triangle node array.

Related Data and Programs:

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

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

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

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

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

PLY_DISPLAY, a MATLAB program which displays an image of a 3D graphics file in PLY format;

PLY_IO, a C library which reads or writes a PLY file.

PLY_IO, a MATLAB library which reads or writes a PLY file.

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

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

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

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, a data directory which contains examples of TRI_SURFACE files.

TRI_SURFACE_DISPLAY, a MATLAB program which displays 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_PLY, a MATLAB program which converts TRI_SURFACE data to data suitable for storage as a PLY file.

TRIANGULATION_DISPLAY_OPENGL, a C++ program which reads files defining a triangulation and displays an image using OpenGL.

Author:

The original versions of the files PLY_READ.M and PLY_TO_TRI_SURFACE.M were created by Pascal Getreuer.

Source Code:

• i4mat_transpose_print_some.m, prints some of the transpose of an I4MAT.
• i4mat_write0.m, writes an I4MAT file.
• ply_to_tri_surface.m converts PLY data to TRI_SURFACE data.
• r8_epsilon.m, returns the R8 machine precision.
• r8mat_transpose_print_some.m, prints some of the transpose of an R8MAT.
• r8mat_write.m, writes an R8MAT file.
• 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_write.m writes graphics information to a TRI_SURFACE file.

Examples and Tests:

• ply_to_tri_surface_test.m runs all the tests.
• ply_to_tri_surface_test_output.txt the output file.
• ply_to_tri_surface_test01.m reads sphere.ply, extracts the TRI_SURFACE version of the data, and displays it.
• ply_to_tri_surface_test021.m reads cube.ply, extracts the TRI_SURFACE version of the data, and writes it to a pair of TRI_SURFACE files.
• sphere.ply a PLY file describing a sphere.
• sphere.png a PNG image of MATLAB's display of the TRI_SURFACE data.
• cube.ply a PLY file describing a cube.
• cube_nodes.txt the TRI_SURFACE node file for the cube.
• cube_elements.txt the TRI_SURFACE triangle file for the cube.
• cube.png a PNG image of MATLAB's display of the TRI_SURFACE data.

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