cart2stl.java

	/**
	 * Convert file of cartesian points to an STL file
	 */
import java.io.*;
import java.util.*;


public class cart2stl {
//EDIT THE NEXT TWO LINES WITH THE APPROPRIATE INPUT/OUTPUT FILE NAMES
	public static final String fileIn = "face.txt";
	public static final String outputFile = "face.stl";
	
	
	public static int pointsRead = 0;
	public static int facetsMade = 0;
	public static int totalPoints =0;
	public static PrintWriter fileOut = null;
	
	public static void main(String[] args) throws IOException {
		
		System.out.println("Cartesian Points to STL File Convertor");
		System.out.println("Developed by Noah Lorang, Fall 2006");
		System.out.println("\n\nNow beginning conversion on " + fileIn);
		double[] i = new double[3];
		double[] j = new double[3];
		double[] k = new double[3];
		//Open file, read first line and set totalPoints
		
			BufferedReader fileReader = new BufferedReader(new FileReader (fileIn));	
			StringTokenizer st = new StringTokenizer(fileReader.readLine());
			totalPoints = Integer.parseInt(st.nextToken())*Integer.parseInt(st.nextToken());
				
			//Now, read the next three lines and make the right arrays to hold them
			//First line
			st = new StringTokenizer(fileReader.readLine());
			for (int a = 0; a<3; a++){
				i[a]=Double.parseDouble(st.nextToken());
			}
			
			//second line
			st = new StringTokenizer(fileReader.readLine());
			for (int a = 0; a<3; a++){
				j[a]=Double.parseDouble(st.nextToken());
			}
			
			//third line
			st = new StringTokenizer(fileReader.readLine());
			for (int a = 0; a<3; a++){
				k[a]=Double.parseDouble(st.nextToken());
			}
			
			pointsRead += 3;
			
			//Start file to write to
			fileOut = new PrintWriter (new FileWriter(outputFile));
			fileOut.println("solid");
			fileOut.println();
			
			for(int b = 1; b <totalPoints-2; b++) {	//temp solution

				makeFacet(i,j,k);
				//move up old points
				i[0] = j[0];
				i[1] = j[1];
				i[2] = j[2];
				j[0] = k[0];
				j[1] = k[1];
				j[2] = k[2];
				
			//Read new point
				st = new StringTokenizer(fileReader.readLine());
				for (int a = 0; a<3; a++){
					k[a]=Double.parseDouble(st.nextToken());
				}
				
				pointsRead++;
				facetsMade++;
							}
			fileOut.println("endsolid");
			fileOut.close();
			System.out.println("Total points read: " + pointsRead);
			System.out.println("Total facets made: " + facetsMade);
			System.out.println("File written to " + outputFile);

	}
	
		 
		

	public static void makeFacet(double[] i, double[] j, double[] k) {
		//construct vectors between points
		double[] ij = new double[3];
		double[] jk = new double[3];
		for (int a = 0; a<3; a++){
			ij[a] = j[a]-i[a];
			jk[a] = k[a]-j[a];
		}
		
		
		//calculate normal ij x jk
		double[] normal = new double[3];
		normal[0] = ij[1]*jk[2] - ij[2]*jk[1];
		normal[1] = ij[2]*jk[0] - ij[0]*jk[2];
		normal[2] = ij[0]*jk[1] - ij[1]*jk[0];
		
		
		//add to file
		fileOut.println(" facet normal " + normal[0] + " " + normal[1] + " " + normal[2]);
		fileOut.println("  outer loop");
		fileOut.println("   vertex " + i[0] + " " + i[1] + " " + i[2]);
		fileOut.println("   vertex " + j[0] + " " + j[1] + " " + j[2]);
		fileOut.println("   vertex " + k[0] + " " + k[1] + " " + k[2]);
		fileOut.println("  endloop");
		fileOut.println(" endfacet");
		fileOut.println();
	}

}

This is cool.