android - OpenGL ES 1.0 - Incorrect rendering -

i loading .obj file , render in android emulator. although 3rd-party .obj viewers show model correctly (open3mod), when launch on android emulator looks strange. please explain why in enulator model reders incorrectly?

import android.content.context; import android.opengl.glsurfaceview; import android.opengl.glu; import java.util.hashtable; import java.util.arraylist; import java.io.inputstreamreader; import java.io.bufferedreader; import java.nio.floatbuffer; import java.nio.bytebuffer; import java.nio.byteorder; import javax.microedition.khronos.egl.eglconfig; import javax.microedition.khronos.opengles.gl10;  public class myglsurfaceview extends glsurfaceview implements glsurfaceview.renderer {     private context context;     private hashtable<string, arraylist<float>> obj;      public myglsurfaceview(context context)     {         super(context);         setrenderer(this);         this.context = context;     }      public void onsurfacecreated(gl10 gl, eglconfig config)     {         obj = new hashtable<string, arraylist<float>>();          try         {             bufferedreader reader = new bufferedreader(               new inputstreamreader(context.getassets().open("calculator.obj")));              arraylist<float> vertex = new arraylist<float>();              string name = null;             string line = null;             while ((line = reader.readline()) != null)             {                 if (line.startswith("v "))                 {                     string[] parts = line.substring(2).trim().split("\\s+");                      vertex.add(float.valueof(float.valueof(parts[0]).floatvalue() / 2f)); // scale smaller twice                     vertex.add(float.valueof(float.valueof(parts[1]).floatvalue() / 2f)); // scale smaller twice                     vertex.add(float.valueof(float.valueof(parts[2]).floatvalue() / 2f)); // scale smaller twice                 }                  if (line.startswith("f "))                 {                     string[] parts = line.substring(2).trim().split("\\s+");                      obj.get(name).add(vertex.get(integer.valueof(parts[0]).intvalue() - 1));                     obj.get(name).add(vertex.get(integer.valueof(parts[1]).intvalue() - 1));                     obj.get(name).add(vertex.get(integer.valueof(parts[2]).intvalue() - 1));                 }                  if (line.startswith("g "))                 {                     name = line.substring(2).trim();                      obj.put(name, new arraylist<float>());                }             }              reader.close();         }         catch (exception e)         {             system.exit(0);         }     }      public void onsurfacechanged(gl10 gl, int width, int height)     {         gl.glviewport(0, 0, width, height);     }      public void ondrawframe(gl10 gl)     {         gl.glclearcolor(0.0f, 0.0f, 0.0f, 1.0f);         gl.glcleardepthf(1.0f);          int i;          bytebuffer fbytebuffer = bytebuffer.allocatedirect(obj.get("calculator").size() * 4);         fbytebuffer.order(byteorder.nativeorder());         floatbuffer faces = fbytebuffer.asfloatbuffer();         (i = 0; < obj.get("calculator").size(); i++)           faces.put(obj.get("calculator").get(i).floatvalue());                     faces.position(0);          gl.glenableclientstate(gl10.gl_vertex_array);         gl.glvertexpointer(3, gl10.gl_float, 0, faces);          gl.gldrawarrays(gl10.gl_triangles, 0, faces.capacity() / 3);     } } 

obj files indexed geometry format (that's face element lines start "f " encoding - tell vertices in vertex array make each triangle).

your current code decoding index values, totally ignores them when comes rendering. need use gldrawelements, using index buffer pick vertices contribute triangles.

edit missed fact manually repack vertex data on load. don't need - api supports indexed rendering natively (and more efficient shared verts processed once).