TRI_SURFACE_TO_PLY
Convert data from TRI_SURFACE to PLY format

TRI_SURFACE_TO_PLY is a MATLAB program which reads data describing a triangular mesh of a 3D surface, reformats it into a PLY data structure, and then writes it to 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.

Usage:

tri_surface_to_ply ( prefix )

• prefix_nodes.txt contains the node coordinates.
• prefix_elements.txt contains the indices of nodes forming each triangular element.
• prefix.ply is the PLY file created by the command.

Licensing:

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

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.

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

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

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.

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

TRI_SURFACE_DISPLAY, 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_OPENGL, a C++ program which reads files defining a triangulation and displays an image using Open GL.

Author:

The functions PLY_WRITE.M and TRI_SURFACE_DATA_TO_PLY_DATA were created by Pascal Getreuer.

Source Code:

• tri_surface_to_ply.m the program.

Examples and Tests:

DART is a simple dart shape, involving 5 nodes and 6 triangular faces.

• dart_nodes.txt, the node file;
• dart_elements.txt, the triangle file;
• dart.ply, the PLY file;
• dart.png, a PNG image.

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