透明度点缀 OpenGL ES 2.0

Question

我目前正在使用 OpenGL ES 2.0 为 Android 开发游戏。我几乎所有的东西都使用纹理和顶点颜色，但是当我在纹理中使用透明度时，透明部分会被点缀。这是它的截图：Dotted transparency

当前显示的棉铃（蓝色圆圈）在其顶部有 3 层平面，即眼睛、嘴巴和牙齿。所有图层都具有相同的尺寸和透明度，我添加的图层越多，点似乎越差。这是渲染器的 onCreate 方法：

    mMVPMatrix = new float [16];
    mViewMatrix = new float [16];
    mProjectionMatrix = new float [16];
    mModelMatrix = new float [16];

    Matrix.setLookAtM(mViewMatrix, 0, 0.0f, 0.0f, mZoom, 0.0f, 0.0f, -0.1f, 0.0f, 1.0f, 0.0f);
    Matrix.setIdentityM(mModelMatrix, 0);

    mTexturePointer = new int [32];

    loadTextures();

    GLES20.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    mShaderPointer = loadProgram();

    GLES20.glEnable(GLES20.GL_BLEND);
    GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA);

    GLES20.glUseProgram(mShaderPointer);

    mMVPMatrixPointer = GLES20.glGetUniformLocation(mShaderPointer, "uMVPMatrix");
    mPositionPointer = GLES20.glGetAttribLocation(mShaderPointer, "a_position");
    mTexCoordPointer = GLES20.glGetAttribLocation(mShaderPointer, "a_texCoord");
    mSamplerPointer = GLES20.glGetUniformLocation(mShaderPointer, "s_texture");
    mColorPointer = GLES20.glGetAttribLocation(mShaderPointer, "a_color");

这是片段着色器：

              "precision mediump float;                                         \n" 
            + "uniform sampler2D s_texture;                                                 \n"
            + "                                                                             \n" 
            + "varying vec4 v_color;                                                        \n" 
            + "varying vec2 v_texCoord;                                                     \n"
            + "                                                                             \n" 
            + "void main()                                                                  \n" 
            + "{                                                                            \n"
            + "                                                                             \n"
            + "     vec4 final_color = vec4(texture2D(s_texture, v_texCoord).r * v_color.r,   "
            + "                             texture2D(s_texture, v_texCoord).g * v_color.g,   " 
            + "                             texture2D(s_texture, v_texCoord).b * v_color.b,   "
            + "                             texture2D(s_texture, v_texCoord).a + v_color.a);\n" 
            + "                                                                             \n" 
            + "     //Set the Fragments colour                                              \n" 
            + "     gl_FragColor = final_color;                                             \n" 
            + "}                                                                            \n";

还有顶点着色器：

              "attribute vec4 a_position;       \n" 
            + "uniform mat4 uMVPMatrix;                     \n" 
            + "                                             \n"
            + "attribute vec2 a_texCoord;                   \n" 
            + "attribute vec4 a_color;                      \n" 
            + "                                             \n" 
            + "varying vec4 v_color;                        \n"
            + "varying vec2 v_texCoord;                     \n" 
            + "                                             \n" 
            + "void main()                                  \n"
            + "{                                            \n" 
            + "   gl_Position = uMVPMatrix * a_position;    \n" 
            + "   v_texCoord = a_texCoord;                  \n"
            + "   v_color = a_color;                        \n" 
            + "}                                            \n";

最后但并非最不重要的一点是draw（这是每个对象的draw方法）：

GLES20.glViewport(0, 0, mScreenWidth, mScreenHeight);

GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);

protected void draw(GameRenderer aRenderer){
    if(mVisible){
        // Do the animation.
        if(mAnimated)
            animate();

        GLES20.glEnableVertexAttribArray(aRenderer.mPositionPointer);
        GLES20.glEnableVertexAttribArray(aRenderer.mTexCoordPointer);
        GLES20.glEnableVertexAttribArray(aRenderer.mColorPointer);

        // Load the texture mapping.
        mTexture.position(0);
        GLES20.glVertexAttribPointer(aRenderer.mTexCoordPointer, 2, GLES20.GL_FLOAT, false, 2 * 4, mTexture);

        // Load the vertex position.
        mVertices.position(0);
        GLES20.glVertexAttribPointer(aRenderer.mPositionPointer, 3, GLES20.GL_FLOAT, false, 3 * 4, mVertices);

        // Load the vertex color.
        mColor.position(0);
        GLES20.glVertexAttribPointer(aRenderer.mColorPointer, 4, GLES20.GL_FLOAT, false, 4 * 4, mColor);

        // Set the texture.
        GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, aRenderer.mTexturePointer[mTextureId]);
        GLES20.glUniform1i(aRenderer.mSamplerPointer, 0);

        // Calculate stuff.
        Matrix.multiplyMM(aRenderer.mMVPMatrix, 0, aRenderer.mViewMatrix, 0, aRenderer.mModelMatrix, 0);
        Matrix.multiplyMM(aRenderer.mMVPMatrix, 0, aRenderer.mProjectionMatrix, 0, aRenderer.mMVPMatrix, 0);

        GLES20.glUniformMatrix4fv(aRenderer.mMVPMatrixPointer, 1, false, aRenderer.mMVPMatrix, 0);

        GLES20.glDrawElements(GLES20.GL_TRIANGLES, 6, GLES20.GL_UNSIGNED_SHORT, mIndices);

        GLES20.glDisableVertexAttribArray(aRenderer.mPositionPointer);
        GLES20.glDisableVertexAttribArray(aRenderer.mTexCoordPointer);
        GLES20.glDisableVertexAttribArray(aRenderer.mColorPointer);
    }
}

loadTexture() 方法：

public void loadTextures(){

    Log.d("loadTextures()", "Loading textures");

    Bitmap tBitmap = null;

    // Tell OpenGL to generate textures.
    GLES20.glGenTextures(32, mTexturePointer, 0);

    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inTempStorage = new byte [16 * 1024];
    options.inScaled = false;

    // TEXTURE 0
    GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTexturePointer[0]);

    // Scale up if the texture if smaller.
    GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
    GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);

    tBitmap = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.ingame_boll_spritesheet_new_style, options);

    GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, tBitmap, 0);

    tBitmap.recycle();
    // TEXTURE 1
    GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTexturePointer[1]);

    // Scale up if the texture if smaller.
    GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
    GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);

    tBitmap = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.ingame_boll_mouth, options);

    GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, tBitmap, 0);

    tBitmap.recycle();

    // And so on for all textures

    Log.d("loadTextures()", "Loaded textures");

}

我仔细看了看，.pngs 不是问题。我尝试将顶点颜色 alpha 设置为 -1，是的，纹理消失了，但点仍然存在。当我禁用混合时，所有透明度都变黑并且点消失。当片段着色器输出 alpha 0.0 并且它仍然被点缀时，我不知道接下来要尝试什么。

感谢您对尝试的事情提供任何反馈。谢谢！

Answer 1

这似乎是一个颜色深度问题。您应该将表面和窗口设置为 32 位模式，看看是否有帮助：

glview.setEGLConfigChooser(8, 8, 8, 8, 16, 0);

和

getWindow().setFormat(PixelFormat.RGBA_8888);

现在应该没有必要抖动任何东西，因为窗口和表面使用相同数量的位，但有时它可以提供更好的结果，因此您可以尝试同时为窗口和 openGL 启用它。

Answer 2

你的“loadTextures()”函数是什么样的？这可能是 glTexParameteri(...) 问题，您可以在其中设置纹理过滤。 （插值可能不正确）