readerobj.java

基于java的3d开发库。对坐java3d的朋友有很大的帮助。

        {
            return ImagePersistence.importRGBA(
              new File(dirObj+System.getProperty("file.separator")+nomImage));
        }
        catch(ImageNotRecognizedException inre) {
            return null;
        }
    }
    
    /**
    This method reads a polygon from a face line. It returns a set of triangles
    as an ArrayList of matrices. For each matrix, there is the information of
    a single triangle, where there are 3 vertexes with: vertex position index,
    texture coordinates index and vertex normal index.
    Note that the triangle set is builded as a triangle fan: the first vertex
    (p0) is a pivot which is fixed for all triangles, the second point 
    determines the first triangle edge, and for each following vertex,
    a new triangle is builded.
    */
    private static ArrayList<_ReaderObjVertex[]>
    readPolygonAsTriangleFan(String lineOfText) {
        ArrayList<_ReaderObjVertex[]> ret;
        StringTokenizer st = new StringTokenizer(lineOfText, " \n\r\t");
        st.nextToken(); // The "f" token
        int numberOfTokens = st.countTokens();
        _ReaderObjVertex p0 = null;
        _ReaderObjVertex p1 = null;
        _ReaderObjVertex p2 = null;
        _ReaderObjVertex[] aux = null;
        int i;

        ret = new ArrayList<_ReaderObjVertex[]>();
        for( i = 0; i < numberOfTokens; i++ ) {
            String token = st.nextToken();
            _ReaderObjVertex indexes = readFaceVertex(token);

            if( i == 0 ) {
                p0 = indexes;
            }
            else if( i == 1 ) {
                p1 = indexes;
            }
            else {
                p2 = indexes;

                aux = new _ReaderObjVertex[3];
                aux[0] = new _ReaderObjVertex(p0);
                aux[1] = new _ReaderObjVertex(p1);
                aux[2] = new _ReaderObjVertex(p2);
                ret.add(aux);

                p1 = new _ReaderObjVertex(p2);
            }
        }
        return ret;
    }

    /**
    In some obj files (particulary those exported from 3DSMax) some array
    indexes contains negative numbers. This method is supposed to parse integer
    numbers from a string token, and returning the absolute value of it.
    */
    private static int readIndexInteger(String inToken)
    {
        int val = Integer.parseInt(inToken);
        if ( val < 0 ) val *= -1;
        return val;
    }

    /**
    Returns three indices: vertex position, texture coordinates and normal,
    as a vertex
    */    
    private static _ReaderObjVertex readFaceVertex(String lineOfText)
    {
        _ReaderObjVertex ret = new _ReaderObjVertex();

        StringTokenizer st=new StringTokenizer(lineOfText, "/");

        if ( st.countTokens() == 2 ) {
            if( lineOfText.endsWith("/") ) {
                // Has vertex and texture
                try {
                    ret.vertexPositionIndex = readIndexInteger(st.nextToken());
                }
                catch ( NumberFormatException nfe ) {
                    ret.vertexPositionIndex = -1;
                }
                try {
                    ret.vertexTextureCoordinateIndex =
                        readIndexInteger(st.nextToken());
                }
                catch ( NumberFormatException nfe ) {
                    ret.vertexTextureCoordinateIndex = -1;
                }
                ret.vertexNormalIndex = -1;
              }
              else {
                // Has vertex and normal
                try {
                    ret.vertexPositionIndex = readIndexInteger(st.nextToken());
                }
                catch ( NumberFormatException nfe ) {
                    ret.vertexPositionIndex = -1;
                }
                ret.vertexTextureCoordinateIndex=-1;
                try {
                    ret.vertexNormalIndex = readIndexInteger(st.nextToken());
                }
                catch ( NumberFormatException nfe ) {
                    ret.vertexNormalIndex = -1;
                }
            }
          }
          else {
            // Has all
            try {
                ret.vertexPositionIndex = readIndexInteger(st.nextToken());
            }
            catch ( NumberFormatException nfe ) {
                ret.vertexPositionIndex = -1;
            }
            try {
                ret.vertexTextureCoordinateIndex =
                    readIndexInteger(st.nextToken());
            }
            catch ( NumberFormatException nfe ) {
                ret.vertexTextureCoordinateIndex = -1;
            }
            try {
                ret.vertexNormalIndex = readIndexInteger(st.nextToken());
            }
            catch ( NumberFormatException nfe ) {
                ret.vertexNormalIndex = -1;
            }
          }
        ;
        return ret;
    }
    
    private static Vector3D readVertex(String lineOfText)
    {
        Vector3D vert = new Vector3D();
        StringTokenizer st = new StringTokenizer(lineOfText);
        st.nextToken();
        vert.x = Double.parseDouble(st.nextToken());
        vert.y = Double.parseDouble(st.nextToken());
        vert.z = Double.parseDouble(st.nextToken());

        return vert;
    }

    private static Vector3D readVertexTexture(String lineOfText) {
        Vector3D vert = new Vector3D();
        StringTokenizer st = new StringTokenizer(lineOfText);
        st.nextToken();
        vert.x = Double.parseDouble(st.nextToken());
        vert.y = Double.parseDouble(st.nextToken());
        try {
            vert.z = Double.parseDouble(st.nextToken());
        }
        catch( Exception e ) {}
        return vert;
    }

    private static HashMap<String, Material>
    readMaterials(String material, String fileName) {
        HashMap<String, Material> ret = new HashMap<String, Material>();
        StringTokenizer st = new StringTokenizer(material, " ");
        st.nextToken(); // "mtlib" token
        File arc = new File(fileName);
        File dirArc = arc.getParentFile();
        String nomArc;
        nomArc = dirArc + System.getProperty("file.separator")+st.nextToken();
        
        try {
            BufferedReader in=new BufferedReader(new FileReader(nomArc));
            String lineOfText="";

            Material activeMaterial=new Material();
            activeMaterial.setName("default");

            while( (lineOfText = in.readLine()) != null ) {
                if ( lineOfText.startsWith("Ns") ) {
                    StringTokenizer stMat=new StringTokenizer(lineOfText, " ");
                    stMat.nextToken(); // Ns
                    activeMaterial.setPhongExponent(
                        Float.parseFloat(stMat.nextToken()));
                }
                if ( lineOfText.startsWith("Kd") ) {
                    StringTokenizer stMat=new StringTokenizer(lineOfText, " ");
                    stMat.nextToken(); // Kd
                    ColorRgb color=new ColorRgb();
                    color.r=Float.parseFloat(stMat.nextToken());
                    color.g=Float.parseFloat(stMat.nextToken());
                    color.b=Float.parseFloat(stMat.nextToken());
                    activeMaterial.setDiffuse(color);
                }
                if ( lineOfText.startsWith("Ka") ) {
                    StringTokenizer stMat=new StringTokenizer(lineOfText, " ");
                    stMat.nextToken(); // Ka
                    ColorRgb color=new ColorRgb();
                    color.r=Float.parseFloat(stMat.nextToken());
                    color.g=Float.parseFloat(stMat.nextToken());
                    color.b=Float.parseFloat(stMat.nextToken());
                    activeMaterial.setAmbient(color);
                }
                if ( lineOfText.startsWith("Ks") ) {
                    StringTokenizer stMat=new StringTokenizer(lineOfText, " ");
                    stMat.nextToken(); // Ks
                    ColorRgb color=new ColorRgb();
                    color.r=Float.parseFloat(stMat.nextToken());
                    color.g=Float.parseFloat(stMat.nextToken());
                    color.b=Float.parseFloat(stMat.nextToken());
                    activeMaterial.setSpecular(color);
                }
                if ( lineOfText.startsWith("d") ) {
                    StringTokenizer stMat=new StringTokenizer(lineOfText, " ");
                    stMat.nextToken(); // d
                    //activeMaterial.setAlpha(Float.parseFloat(stMat.nextToken()));
                }
                if ( lineOfText.startsWith("newmtl") ) {
                    StringTokenizer stMat=new StringTokenizer(lineOfText, " ");
                    stMat.nextToken();//newmtl
                    ret.put(activeMaterial.getName(), activeMaterial);
                    activeMaterial = new Material();
                    activeMaterial.setName(stMat.nextToken());
                }
            }
            ret.put(activeMaterial.getName(), activeMaterial);
        }
        catch( IOException ioe ) {
        }
        return ret;
    }

    private static Material defaultMaterial()
    {
        Material m = new Material();

        m.setAmbient(new ColorRgb(0.2, 0.2, 0.2));
        m.setDiffuse(new ColorRgb(0.5, 0.9, 0.5));
        m.setSpecular(new ColorRgb(1, 1, 1));
        return m;
    }

    private static void addThing(Geometry g,
        ArrayList<SimpleBody> inoutSimpleBodiesArray)
    {
        if ( inoutSimpleBodiesArray == null ) return;

        SimpleBody thing;

        thing = new SimpleBody();
        thing.setGeometry(g);
        thing.setPosition(new Vector3D());
        thing.setRotation(new Matrix4x4());
        thing.setRotationInverse(new Matrix4x4());
        thing.setMaterial(defaultMaterial());
        inoutSimpleBodiesArray.add(thing);
    }

    public static void
    importEnvironment(File inSceneFileFd, SimpleScene inoutSimpleScene)
        throws Exception
    {
        //-----------------------------------------------------------------
        ArrayList<SimpleBody> simpleBodiesArray = inoutSimpleScene.getSimpleBodies();
        ArrayList<Light> lightsArray = inoutSimpleScene.getLights();
        ArrayList<Background> backgroundsArray = inoutSimpleScene.getBackgrounds();
        ArrayList<Camera> camerasArray = inoutSimpleScene.getCameras();

        //-----------------------------------------------------------------
        TriangleMeshGroup mg = null;
        mg = read(inSceneFileFd.getAbsolutePath());
        addThing(mg, simpleBodiesArray);
    }
}

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