import PLY file using java

What is PLY?

PLY is a very simple computer file format also known as Polygon File Format or Stanford Triangle Format. It is used to store 3D data of a single object in a simple format and contains description of an object as a list of flat polygons. It was designed to store data from 3D scanners  which consist properties of a 3D object such as color, transparency, surface normals, texture coordinate and indexes.  It has two versions of file formats : ASCII and  Binary.  Complete details about PLY file formats is not covered in this topic. Click here to read more about PLY file formats.

Java Library to Read PLY Files

jPLY is a library to read PLY files. Download jPLY from here and include source code in your project.

Add following code to read PLY file.

import java.io.File;
import java.io.IOException;

import org.smurn.jply.Element;
import org.smurn.jply.ElementReader;
import org.smurn.jply.PlyReader;
import org.smurn.jply.PlyReaderFile;

import com.jme3.scene.Mesh;
import com.jme3.scene.VertexBuffer.Type;
import com.jme3.util.BufferUtils;

import util.Log;
import util.Log.LogType;

public class PlyImporter {

        /* data fields to store points, colors, faces information read from PLY file */
	private float[] points = null;
	private float[] colors = null;
	private int[] faces = null;
	private Mesh mesh = null;

	@Override
	public Mesh loadPLY(File file) throws IOException {
		PlyReader ply = new PlyReaderFile(file);

		int vertexCount = ply.getElementCount("vertex");
		int triangleCount = ply.getElementCount("face");
		
		ElementReader reader;
		

		/* Iterate to read elements */
		while ((reader = ply.nextElementReader()) != null) {
			String elementType = reader.getElementType().getName();

			if (elementType.equals("vertex")) {
				if (points != null)
					continue;
				points = new float[3 * vertexCount];
				colors = new float[3 * vertexCount];

				Element element;
				int x = 0;
				while ((element = reader.readElement()) != null) {
                                   /* manipulated array indexes to store  */
					points[3 * x + 0] = (float) element.getDouble("x");
					points[3 * x + 1] = (float) element.getDouble("y");
					points[3 * x + 2] = (float) element.getDouble("z");
					colors[3 * x + 0] = (float) element.getDouble("red") / 255f;
					colors[3 * x + 1] = (float) element.getDouble("green") / 255f;
					colors[3 * x + 2] = (float) element.getDouble("blue") / 255f;
					x++;
				}
				Log.debug(LogType.IO, "PLY importer: " + x + " vertices counted");

			} else if (elementType.equals("face")) {
				
				if (faces != null)
					continue;
				faces = new int[triangleCount * 3];

				Element element;
				int x = 0;
				while ((element = reader.readElement()) != null) {
					int[] vertex_index = null;

					try {
						vertex_index = element.getIntList("vertex_indices");
					}
					
					catch (Exception e) {}

					if(vertex_index == null) {
						try {
							vertex_index = element.getIntList("vertex_index");
						}
						
						catch (Exception e) {}
					}

					if(vertex_index == null) {
						throw new IOException("Failed to read vertices");
					}

					faces[3 * x + 0] = vertex_index[0];
					faces[3 * x + 1] = vertex_index[1];
					faces[3 * x + 2] = vertex_index[2];
					x++;
				}
				Log.debug(LogType.IO, "PLY importer: " + x + " faces counted");
			}

			reader.close();
		}

		ply.close();

                /* Mesh is a class of JME 3.0 library */
		mesh = new Mesh();

		/* created mesh object to include PLY object in JME 3 environment */
		mesh.setBuffer(Type.Position, 3, BufferUtils.createFloatBuffer(points));
		mesh.setBuffer(Type.Index, 3, BufferUtils.createIntBuffer(faces));
		mesh.setBuffer(Type.Color, 3, BufferUtils.createFloatBuffer(colors));

		mesh.updateBound();

		return mesh;
	}
       
        /* additional methods to return detailed description of object for further manipulation */
	public float[] getPoints(){
		return this.points;
	}
	
	public int[] getFaces(){
		return this.faces;
	}
	
	public float[] getColors(){
		return this.colors;
	}
	
	public Mesh getMesh(){
		return this.mesh;
	}
}