Help with UV on my obj loader for android

Question

I'm trying to make my first android game and to do this I made an OBJ loader which takes a resource id and uses the InputStream returned by Context.getResources().openRawResource().

I managed to read vertex information and face info and I can successfully load a mesh without any textures.

See the problem is that the textures are not mapped correctly. I managed to read the information from the file by putting all the numbers after 'vt' into an array as well as the indexes in f after the first '/' (ie 'f 1/1 ...')

I'm not exactly sure what I'm supposed to do with the numbers though...if I just put everything into a bytebuffer and continue as I normally would the way I learned from these two tutorials(jayway, and the nehe ports) it will still come out wrong.

My thoughts are that the 'vt' info in the file is out of order(hence the need for the '/x' in the 'f' data) and I'm supposed to put it in order somehow before creating the bytebuffer from the array....I don't know how to do that :(

So I ask, can anyone offer me some help please? I know there are other obj loaders out there on the internet but I already made this one and I know how it works, not only that but its a better learning experience for me.

Heres the code I'm using:

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Vector;

import android.content.Context;
import android.util.Log;
import com.snakeinalake.catchthemoney.Mesh.CMeshInfo;

public class CMeshParserOBJ extends CMeshParser{

 public CMeshParserOBJ(){
  type = "OBJ";  
 }

 @Override
 public CMeshInfo loadMesh(Context context, int FileID){
  CMeshInfo ret = new CMeshInfo(type);

  String buildWord = "";
  int data;
  int found = -1;

  Vector<Float> vert = new Vector<Float>();
  Vector<Float> uv = new Vector<Float>();
  Vector<Short> ind = new Vector<Short>();
  Vector<Short> map = new Vector<Short>();

  InputStream is = context.getResources().openRawResource(FileID);
  InputStreamReader rd = new InputStreamReader(is);

  try {
   data = rd.read();
   while(data!=-1){ 
    char c = (char)data;

     if(found == -1){
      if(c == 'v'){    //found vertex data
       data = rd.read();
        if((char)data == ' '){
         found = 1;
        }else if((char)data == 't'){ //found uv map data
         data = rd.read();
         if((char)data == ' '){
          found = 3;
         }
        }else{
         found = -1;        
        }
      }else if(c == 'f'){   //found index data (faces)
       data = rd.read();
       if((char)data == ' '){
        found = 2;
       }else{
        found = -1;        
       }
      }else{
       found = -1;       
      }
     }

     if(found == 1){
      float x = 0,y = 0,z = 0;     
      for(int repeat = 0; repeat<3; repeat++){
       buildWord="";
       do{
        data = rd.read();
        c = (char)data;    
        buildWord+=c;
       }while((char)data!=' ' && (char)data!='\n');
       if(repeat==0)
        x = Float.parseFloat(buildWord.trim());
       else if(repeat==1)
        y = Float.parseFloat(buildWord.trim());
       else if(repeat==2)
        z = Float.parseFloat(buildWord.trim());
      }
      vert.add(x);
      vert.add(y);
      vert.add(z);
      found = -1;
     }

     if(found == 2){
      short v1 = 0, v2 = 0, v3 = 0;
      short map1 = 0, map2 = 0, map3 = 0;
      boolean uvdata = false;
      for(int repeat = 0; repeat<3; repeat++){
       buildWord="";
       do{
        data = rd.read();
        if(!uvdata && (char)data == '/'){
         uvdata = true;        
        }else{
         c = (char)data;    
         buildWord+=c;
        }
       }while((char)data!=' ' && (char)data!='\n' && (char)data!='/');
       if(repeat==0){
        v1 = Short.parseShort(buildWord.trim());
       }else if(repeat==1){
        v2 = Short.parseShort(buildWord.trim());
       }else if(repeat==2){
        v3 = Short.parseShort(buildWord.trim());
       }

       if(uvdata){
        uvdata = false;
        buildWord = "";
        do{
         data = rd.read();
         c = (char)data;    
         buildWord+=c;
         if(!uvdata && (char)data == '/'){
          uvdata = true;        
         }
        }while((char)data!=' ' && (char)data!='\n');
        if(repeat == 0)
         map1 = Short.parseShort(buildWord.trim());
        else if(repeat == 1)
         map2 = Short.parseShort(buildWord.trim());
        else if(repeat == 2)
         map3 = Short.parseShort(buildWord.trim());
        else{
         map1 = 0; map2  = 0; map3 = 0;     
        }
       }
      }       
      ind.add(v1);
      ind.add(v2);
      ind.add(v3);

      map.add(map1);
      map.add(map2);
      map.add(map3);
      found = -1;
     }
     if(found == 3){
      float uvx = 0, uvy = 0;     
      for(int repeat = 0; repeat<2; repeat++){
       buildWord="";
       do{
        data = rd.read();
        c = (char)data;    
        buildWord+=c;
       }while((char)data!=' ' && (char)data!='\n');
       if(repeat==0)
        uvx = Float.parseFloat(buildWord.trim());
       else if(repeat==1)
        uvy = Float.parseFloat(buildWord.trim());
      }
      uv.add(uvx);
      uv.add(uvy);
      found = -1;
     }

    data = rd.read();
   }
   rd.close();

  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }


  ret.vertices = new float[vert.size()];
  for(int i=0; i<ret.vertices.length; i++){
   ret.vertices[i] = vert.get(i);
   Log.d("CATCH", Float.toString(ret.vertices[i]));
  }

  ret.uvMappings = new short[map.size()];
  for(int i=0; i<ret.uvMappings.length; i++){
   ret.uvMappings[i] = (short) (map.get(i)-1);
   Log.d("CATCH", Float.toString(ret.uvMappings[i]));
  }

  ret.uvtex = new float[uv.size()];
  for(int i=0; i<ret.uvtex.length; i++){
   ret.uvtex[i] = uv.get(i);
   Log.d("CATCH", Float.toString(ret.uvtex[i]));
  }

  ret.indices = new short[ind.size()];
  for(int i=0; i<ret.indices.length; i++){
   ret.indices[i] = (short) (ind.get(i)-1);
  }

  ret.MapUVCoordinates();
  ret.fillBuffers();

  return ret;
 }}

The method 'ret.MapUVCoordiantes' doesn't work, it was just my attempt at ordering them myself...I'm not going to post it because it, just, doesn't do anything. The method 'ret.fullBuffers' is below. It just creates bytebuffers out of the arrays:

    public void fillBuffers(){
  ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
  ByteBuffer ibb = ByteBuffer.allocateDirect(indices.length * 2);
  ByteBuffer ubb = ByteBuffer.allocateDirect(uvtex.length * 4);

  Log.d("CMeshInfo::fillBuffers", Float.toString(vertices.length * 4));
  Log.d("CMeshInfo::fillBuffers", Float.toString((indices.length * 2)));
  Log.d("CMeshInfo::fillBuffers", Float.toString(uvtex.length * 4));


  vbb.order(ByteOrder.nativeOrder()); //Vertices
  ubb.order(ByteOrder.nativeOrder()); //UV coordinates
  ibb.order(ByteOrder.nativeOrder()); //Indices

  vertBuff = vbb.asFloatBuffer();
  uvBuff = ubb.asFloatBuffer();
  IndBuff = ibb.asShortBuffer();

  vertBuff.put(vertices);
  uvBuff.put(uvtex);
  IndBuff.put(indices);

  vertBuff.position(0);
  uvBuff.position(0);
  IndBuff.position(0);
 }

Answer 1

If I remember correctly those number are indexes into the vertex array.