0
votes

i create object 3d in android using tutorial from learnopengles, and i create cube from the lesson six of that tutorial (texture filtering), after that i want replace the cube with my object (i create the strawberry object). i want my object can display in the view, so i parsing the my object (my object use extension file .obj) to my renderer class, but the object in view is displaying random triangle object. this is my parsing code :

public ObjLoader(Context mActivityContext) {
    FileReader fr;
    String str;

    ArrayList<Float> tempModelVertices = new ArrayList<Float>();
    ArrayList<Float> tempTextureVertices = new ArrayList<Float>();
    ArrayList<Float> tempNormalVertices = new ArrayList<Float>();
    ArrayList<Integer> facesM = new ArrayList<Integer>();
    ArrayList<Integer> facesT = new ArrayList<Integer>();
    ArrayList<Integer> facesN = new ArrayList<Integer>();

    try {
        fr = new FileReader(new File("model/straw_obj"));
        BufferedReader br = new BufferedReader(fr);
        while((str = br.readLine())!=null){
            if(str.startsWith("f")){
                String[] strAr = str.replaceAll("f", "").trim().split(" ");
                for(String s : strAr){
                    String[] cornerAr = s.split("/");
                    facesM.add(Integer.parseInt(cornerAr[0].trim())-1);
                    facesT.add(Integer.parseInt(cornerAr[1].trim())-1);
                    facesN.add(Integer.parseInt(cornerAr[2].trim())-1);
                }
            }
            else if(str.startsWith("vt")){
                String[] strAr = str.replaceAll("vt", "").trim().split(" ");
                tempTextureVertices.add(Float.valueOf(strAr[0].trim()));
                tempTextureVertices.add(-1*Float.valueOf(strAr[1].trim()));
            }
            else if(str.startsWith("vn")){
                String[] strAr = str.replaceAll("vn", "").trim().split(" ");
                tempNormalVertices.add(Float.valueOf(strAr[0].trim()));
                tempNormalVertices.add(Float.valueOf(strAr[1].trim()));
                tempNormalVertices.add(Float.valueOf(strAr[2].trim()));
            }
            else if(str.startsWith("v")){               
                String[] strAr = str.replaceAll("v", "").trim().split(" ");
                tempModelVertices.add(Float.valueOf(strAr[0].trim()));
                tempModelVertices.add(Float.valueOf(strAr[1].trim()));
                tempModelVertices.add(Float.valueOf(strAr[2].trim()));      
            }
        }
        //Log.v(LOG_TAG, "v :"+ String.valueOf(v) + "vt :"+ String.valueOf(vt) + "vn :"+ String.valueOf(vn) + "f :"+ String.valueOf(f));
    } catch (IOException e) {
        // TODO Auto-generated catch block
        Log.v(TAG, "error");
    }
    Log.v(TAG, "vt " + String.valueOf(tempTextureVertices.size()) + " vn " + String.valueOf(tempNormalVertices.size()) + " v " + String.valueOf(tempModelVertices.size()));

    ModelPositionData = new float[facesM.size()];
    ModelTextureCoordinateData = new float[facesT.size()];
    ModelNormalData = new float[facesN.size()];

    for(int i=0; i<facesM.size(); i++){
        ModelPositionData[i] = tempModelVertices.get(facesM.get(i));
    }
    for(int i=0; i<facesT.size(); i++){
        ModelTextureCoordinateData[i] = tempTextureVertices.get(facesT.get(i));
    }
    for(int i=0; i<facesN.size(); i++){
        ModelNormalData[i] = tempNormalVertices.get(facesN.get(i));
    }
}

and this is how i create the glsurface renderer

public class TesterRenderer implements GLSurfaceView.Renderer{
private static final String TAG = "TesterRenderer";


private final Context mActivityContext;

/**
 * Store the model matrix. This matrix is used to move models from object space (where each model can be thought
 * of being located at the center of the universe) to world space.
 */
private float[] mModelMatrix = new float[16];

/**
 * Store the view matrix. This can be thought of as our camera. This matrix transforms world space to eye space;
 * it positions things relative to our eye.
 */
private float[] mViewMatrix = new float[16];

/** Store the projection matrix. This is used to project the scene onto a 2D viewport. */
private float[] mProjectionMatrix = new float[16];

/** Allocate storage for the final combined matrix. This will be passed into the shader program. */
private float[] mMVPMatrix = new float[16];

/** Store the accumulated rotation. */
private final float[] mAccumulatedRotation = new float[16];

/** Store the current rotation. */
private final float[] mCurrentRotation = new float[16];

/** A temporary matrix. */
private float[] mTemporaryMatrix = new float[16];

/** 
 * Stores a copy of the model matrix specifically for the light position.
 */
private float[] mLightModelMatrix = new float[16];  

/** Store our model data in a float buffer. */
private final FloatBuffer mModelPositions;  
private final FloatBuffer mModelNormals;
private final FloatBuffer mModelTextureCoordinates;

// private final FloatBuffer mModelTextureCoordinatesForPlane;

/** This will be used to pass in the transformation matrix. */
private int mMVPMatrixHandle;

/** This will be used to pass in the modelview matrix. */
private int mMVMatrixHandle;

/** This will be used to pass in the light position. */
private int mLightPosHandle;

/** This will be used to pass in the texture. */
private int mTextureUniformHandle;

/** This will be used to pass in model position information. */
private int mPositionHandle;

/** This will be used to pass in model normal information. */
private int mNormalHandle;

/** This will be used to pass in model texture coordinate information. */
private int mTextureCoordinateHandle;

/** How many bytes per float. */
private final int mBytesPerFloat = 4;   

/** Size of the position data in elements. */
private final int mPositionDataSize = 3;    

/** Size of the normal data in elements. */
private final int mNormalDataSize = 3;

/** Size of the texture coordinate data in elements. */
private final int mTextureCoordinateDataSize = 2;

/** Used to hold a light centered on the origin in model space. We need a 4th coordinate so we can get translations to work when
 *  we multiply this by our transformation matrices. */
private final float[] mLightPosInModelSpace = new float[] {0.0f, 0.0f, 0.0f, 1.0f};

/** Used to hold the current position of the light in world space (after transformation via model matrix). */
private final float[] mLightPosInWorldSpace = new float[4];

/** Used to hold the transformed position of the light in eye space (after transformation via modelview matrix) */
private final float[] mLightPosInEyeSpace = new float[4];

/** This is a handle to our cube shading program. */
private int mProgramHandle;

/** This is a handle to our light point program. */
private int mPointProgramHandle;

/** These are handles to our texture data. */
private int mTextureDataHandle;

// private int mGrassDataHandle;

/** Temporary place to save the min and mag filter, in case the activity was restarted. */
private int mQueuedMinFilter;
private int mQueuedMagFilter;

// These still work without volatile, but refreshes are not guaranteed to happen.                   
public volatile float mDeltaX;                  
public volatile float mDeltaY;                      


public TesterRenderer(final Context activityContext)
{   
    mActivityContext = activityContext;

    ObjLoader obj = new ObjLoader(mActivityContext);

    mModelPositions = ByteBuffer.allocateDirect(obj.ModelPositionData.length * mBytesPerFloat)
    .order(ByteOrder.nativeOrder()).asFloatBuffer();                            
    mModelPositions.put(obj.ModelPositionData).position(0);

    mModelNormals = ByteBuffer.allocateDirect(obj.ModelNormalData.length * mBytesPerFloat)
    .order(ByteOrder.nativeOrder()).asFloatBuffer();                            
    mModelNormals.put(obj.ModelNormalData).position(0);

    mModelTextureCoordinates = ByteBuffer.allocateDirect(obj.ModelTextureCoordinateData.length * mBytesPerFloat)
    .order(ByteOrder.nativeOrder()).asFloatBuffer();
    mModelTextureCoordinates.put(obj.ModelTextureCoordinateData).position(0);
}

@Override
public void onSurfaceCreated(GL10 glUnused, EGLConfig config) 
{
    // Set the background clear color to black.
    GLES20.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);

    // Use culling to remove back faces.
    GLES20.glEnable(GLES20.GL_CULL_FACE);

    // Enable depth testing
    GLES20.glEnable(GLES20.GL_DEPTH_TEST);

    // The below glEnable() call is a holdover from OpenGL ES 1, and is not needed in OpenGL ES 2.
    // Enable texture mapping
    // GLES20.glEnable(GLES20.GL_TEXTURE_2D);

    // Position the eye in front of the origin.
    final float eyeX = 0.0f;
    final float eyeY = 0.0f;
    final float eyeZ = -0.5f;

    // We are looking toward the distance
    final float lookX = 0.0f;
    final float lookY = 0.0f;
    final float lookZ = -5.0f;

    // Set our up vector. This is where our head would be pointing were we holding the camera.
    final float upX = 0.0f;
    final float upY = 1.0f;
    final float upZ = 0.0f;

    // Set the view matrix. This matrix can be said to represent the camera position.
    // NOTE: In OpenGL 1, a ModelView matrix is used, which is a combination of a model and
    // view matrix. In OpenGL 2, we can keep track of these matrices separately if we choose.
    Matrix.setLookAtM(mViewMatrix, 0, eyeX, eyeY, eyeZ, lookX, lookY, lookZ, upX, upY, upZ);        

    final String vertexShader = RawResourceReader.readTextFileFromRawResource(mActivityContext, R.raw.per_pixel_vertex_shader_tex_and_light);           
    final String fragmentShader = RawResourceReader.readTextFileFromRawResource(mActivityContext, R.raw.per_pixel_fragment_shader_tex_and_light);           

    final int vertexShaderHandle = ShaderHelper.compileShader(GLES20.GL_VERTEX_SHADER, vertexShader);       
    final int fragmentShaderHandle = ShaderHelper.compileShader(GLES20.GL_FRAGMENT_SHADER, fragmentShader);     

    mProgramHandle = ShaderHelper.createAndLinkProgram(vertexShaderHandle, fragmentShaderHandle, 
            new String[] {"a_Position",  "a_Normal", "a_TexCoordinate"});                                                                                                  

    // Define a simple shader program for our point.
    final String pointVertexShader = RawResourceReader.readTextFileFromRawResource(mActivityContext, R.raw.point_vertex_shader);                   
    final String pointFragmentShader = RawResourceReader.readTextFileFromRawResource(mActivityContext, R.raw.point_fragment_shader);

    final int pointVertexShaderHandle = ShaderHelper.compileShader(GLES20.GL_VERTEX_SHADER, pointVertexShader);
    final int pointFragmentShaderHandle = ShaderHelper.compileShader(GLES20.GL_FRAGMENT_SHADER, pointFragmentShader);
    mPointProgramHandle = ShaderHelper.createAndLinkProgram(pointVertexShaderHandle, pointFragmentShaderHandle, 
            new String[] {"a_Position"}); 

    // Load the texture
    mTextureDataHandle = TextureHelper.loadTexture(mActivityContext, R.drawable.strawberry_texture);        
    GLES20.glGenerateMipmap(GLES20.GL_TEXTURE_2D);

// mGrassDataHandle = TextureHelper.loadTexture(mActivityContext, R.drawable.noisy_grass_public_domain); // GLES20.glGenerateMipmap(GLES20.GL_TEXTURE_2D);

    if (mQueuedMinFilter != 0)
    {
        setMinFilter(mQueuedMinFilter);
    }

    if (mQueuedMagFilter != 0)
    {
        setMagFilter(mQueuedMagFilter);
    }

    // Initialize the accumulated rotation matrix
    Matrix.setIdentityM(mAccumulatedRotation, 0);
}   

@Override
public void onSurfaceChanged(GL10 glUnused, int width, int height) 
{
    // Set the OpenGL viewport to the same size as the surface.
    GLES20.glViewport(0, 0, width, height);

    // Create a new perspective projection matrix. The height will stay the same
    // while the width will vary as per aspect ratio.
    final float ratio = (float) width / height;
    final float left = -ratio;
    final float right = ratio;
    final float bottom = -1.0f;
    final float top = 1.0f;
    final float near = 1.0f;
    final float far = 1000.0f;

    Matrix.frustumM(mProjectionMatrix, 0, left, right, bottom, top, near, far);
}   

@Override
public void onDrawFrame(GL10 glUnused) 
{
    GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);                    

    // Do a complete rotation every 10 seconds.
    long time = SystemClock.uptimeMillis() % 10000L;
    long slowTime = SystemClock.uptimeMillis() % 100000L; 
    float angleInDegrees = (360.0f / 10000.0f) * ((int) time);
    float slowAngleInDegrees = (360.0f / 100000.0f) * ((int) slowTime); 

    // Set our per-vertex lighting program.
    GLES20.glUseProgram(mProgramHandle);

    // Set program handles for cube drawing.
    mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgramHandle, "u_MVPMatrix");
    mMVMatrixHandle = GLES20.glGetUniformLocation(mProgramHandle, "u_MVMatrix"); 
    mLightPosHandle = GLES20.glGetUniformLocation(mProgramHandle, "u_LightPos");
    mTextureUniformHandle = GLES20.glGetUniformLocation(mProgramHandle, "u_Texture");
    mPositionHandle = GLES20.glGetAttribLocation(mProgramHandle, "a_Position");        
    mNormalHandle = GLES20.glGetAttribLocation(mProgramHandle, "a_Normal"); 
    mTextureCoordinateHandle = GLES20.glGetAttribLocation(mProgramHandle, "a_TexCoordinate");                        

    // Calculate position of the light. Rotate and then push into the distance.
    Matrix.setIdentityM(mLightModelMatrix, 0);
    Matrix.translateM(mLightModelMatrix, 0, 0.0f, 0.0f, -2.0f);      
    Matrix.rotateM(mLightModelMatrix, 0, angleInDegrees, 0.0f, 1.0f, 0.0f);
    Matrix.translateM(mLightModelMatrix, 0, 0.0f, 0.0f, 3.5f);

    Matrix.multiplyMV(mLightPosInWorldSpace, 0, mLightModelMatrix, 0, mLightPosInModelSpace, 0);
    Matrix.multiplyMV(mLightPosInEyeSpace, 0, mViewMatrix, 0, mLightPosInWorldSpace, 0);                        

    // Draw a cube.
    // Translate the cube into the screen.
    Matrix.setIdentityM(mModelMatrix, 0);
    Matrix.translateM(mModelMatrix, 0, 0.0f, 0.0f, -7.0f);     

    // Set a matrix that contains the current rotation.
    Matrix.setIdentityM(mCurrentRotation, 0);        
    Matrix.rotateM(mCurrentRotation, 0, mDeltaX, 0.0f, 1.0f, 0.0f);
    Matrix.rotateM(mCurrentRotation, 0, mDeltaY, 1.0f, 0.0f, 0.0f);
    mDeltaX = 0.0f;
    mDeltaY = 0.0f;

    // Multiply the current rotation by the accumulated rotation, and then set the accumulated rotation to the result.
    Matrix.multiplyMM(mTemporaryMatrix, 0, mCurrentRotation, 0, mAccumulatedRotation, 0);
    System.arraycopy(mTemporaryMatrix, 0, mAccumulatedRotation, 0, 16);

    // Rotate the cube taking the overall rotation into account.        
    Matrix.multiplyMM(mTemporaryMatrix, 0, mModelMatrix, 0, mAccumulatedRotation, 0);
    System.arraycopy(mTemporaryMatrix, 0, mModelMatrix, 0, 16);

    // Set the active texture unit to texture unit 0.
    GLES20.glActiveTexture(GLES20.GL_TEXTURE0);

    // Bind the texture to this unit.
    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureDataHandle);

    // Tell the texture uniform sampler to use this texture in the shader by binding to texture unit 0.
    GLES20.glUniform1i(mTextureUniformHandle, 0);

    // Pass in the texture coordinate information
    GLES20.glEnableVertexAttribArray(mTextureCoordinateHandle);
    mModelTextureCoordinates.position(0);
    GLES20.glVertexAttribPointer(mTextureCoordinateHandle, mTextureCoordinateDataSize, GLES20.GL_FLOAT, false, 
            0, mModelTextureCoordinates);



    drawModel();  

    // Draw a plane
    Matrix.setIdentityM(mModelMatrix, 0);
    Matrix.translateM(mModelMatrix, 0, 0.0f, -2.0f, -5.0f);
    Matrix.scaleM(mModelMatrix, 0, 25.0f, 1.0f, 25.0f);
    Matrix.rotateM(mModelMatrix, 0, slowAngleInDegrees, 0.0f, 1.0f, 0.0f);

    // Set the active texture unit to texture unit 0.
    GLES20.glActiveTexture(GLES20.GL_TEXTURE0);

    // Bind the texture to this unit.
    //GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mGrassDataHandle);

    // Tell the texture uniform sampler to use this texture in the shader by binding to texture unit 0.
    GLES20.glUniform1i(mTextureUniformHandle, 0);

    // Pass in the texture coordinate information
    GLES20.glEnableVertexAttribArray(mTextureCoordinateHandle);

    drawModel();

    GLES20.glUseProgram(mPointProgramHandle);        
    drawLight();
}   

public void setMinFilter(final int filter)
{
    if (mTextureDataHandle != 0)
    {
        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureDataHandle);
        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, filter);

// GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mGrassDataHandle); // GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, filter); } else { mQueuedMinFilter = filter; } }

public void setMagFilter(final int filter)
{
    if (mTextureDataHandle != 0)
    {
        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureDataHandle);
        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, filter);

// GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mGrassDataHandle); // GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, filter); } else { mQueuedMagFilter = filter; } }

private void drawModel()
{       
    // Pass in the position information
    GLES20.glEnableVertexAttribArray(mPositionHandle);
    mModelPositions.position(0);        
    GLES20.glVertexAttribPointer(mPositionHandle, mPositionDataSize, GLES20.GL_FLOAT, false,
            0, mModelPositions);        



    // Pass in the normal information
    GLES20.glEnableVertexAttribArray(mNormalHandle);
    mModelNormals.position(0);
    GLES20.glVertexAttribPointer(mNormalHandle, mNormalDataSize, GLES20.GL_FLOAT, false, 
            0, mModelNormals);



    // This multiplies the view matrix by the model matrix, and stores the result in the MVP matrix
    // (which currently contains model * view).
    Matrix.multiplyMM(mMVPMatrix, 0, mViewMatrix, 0, mModelMatrix, 0);   

    // Pass in the modelview matrix.
    GLES20.glUniformMatrix4fv(mMVMatrixHandle, 1, false, mMVPMatrix, 0);                

    // This multiplies the modelview matrix by the projection matrix, and stores the result in the MVP matrix
    // (which now contains model * view * projection).        
    Matrix.multiplyMM(mTemporaryMatrix, 0, mProjectionMatrix, 0, mMVPMatrix, 0);
    System.arraycopy(mTemporaryMatrix, 0, mMVPMatrix, 0, 16);

    // Pass in the combined matrix.
    GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mMVPMatrix, 0);

    // Pass in the light position in eye space.        
    GLES20.glUniform3f(mLightPosHandle, mLightPosInEyeSpace[0], mLightPosInEyeSpace[1], mLightPosInEyeSpace[2]);

    // Draw the cube.
    GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 36);                               
}           

/**
 * Draws a point representing the position of the light.
 */
private void drawLight()
{
    final int pointMVPMatrixHandle = GLES20.glGetUniformLocation(mPointProgramHandle, "u_MVPMatrix");
    final int pointPositionHandle = GLES20.glGetAttribLocation(mPointProgramHandle, "a_Position");

    // Pass in the position.
    GLES20.glVertexAttrib3f(pointPositionHandle, mLightPosInModelSpace[0], mLightPosInModelSpace[1], mLightPosInModelSpace[2]);

    // Since we are not using a buffer object, disable vertex arrays for this attribute.
    GLES20.glDisableVertexAttribArray(pointPositionHandle);  

    // Pass in the transformation matrix.
    Matrix.multiplyMM(mMVPMatrix, 0, mViewMatrix, 0, mLightModelMatrix, 0);
    Matrix.multiplyMM(mTemporaryMatrix, 0, mProjectionMatrix, 0, mMVPMatrix, 0);
    System.arraycopy(mTemporaryMatrix, 0, mMVPMatrix, 0, 16);
    GLES20.glUniformMatrix4fv(pointMVPMatrixHandle, 1, false, mMVPMatrix, 0);

    // Draw the point.
    GLES20.glDrawArrays(GLES20.GL_POINTS, 0, 1);
}

}

can someone help me fix this ?

1
please someone help meadiwijaya G.A
Can you reduce this to a more minimal example? The idea of this site is really not that you post your entire code, and let people debug it for you. The intention is that you post specific questions with the minimal code necessary to reproduce the problem you are having.Reto Koradi
okay thanks before, i will reduce it into the problemadiwijaya G.A
at first, i create the objloader, an then iam combine the objloader with the renderer of glsurface, in the renderer before i combine it, i create cube in it, but i want to replace the cube with the object i created with blender, after that i parsing that file.obj to my android project, but the shape of my obj is randomly, what's hapeen ?adiwijaya G.A

1 Answers

0
votes

It looks like there is a problem with the way you reorder the coordinates based on the indices in the faces:

for(int i=0; i<facesM.size(); i++){
    ModelPositionData[i] = tempModelVertices.get(facesM.get(i));
}

Each position consists of 3 coordinates. This loop copies only one value per position, though. It should look something like this:

for(int i=0; i<facesM.size(); i++){
    ModelPositionData[3 * i    ] = tempModelVertices.get(3 * facesM.get(i)    );
    ModelPositionData[3 * i + 1] = tempModelVertices.get(3 * facesM.get(i) + 1);
    ModelPositionData[3 * i + 2] = tempModelVertices.get(3 * facesM.get(i) + 2);
}

You will also need to adjust the allocation accordingly:

ModelPositionData = new float[3 * facesM.size()];

and make the equivalent changes for the normals and texture coordinates.