libgdx：sprepitebatch没有显示perspectivecamera

Question

虽然我确实具有OpenGL的基本知识，我刚刚从LibGDX开始。

我的问题是：为什么有完全相同的代码，但只有从orthographiccamera切换到perspectivecamera的效果不再显示任何Spritebatches？

这是我使用的代码：

create（）方法：

public void create() {
    textureMesh = new Texture(Gdx.files.internal("data/texMeshTest.png"));
    textureSpriteBatch = new Texture(Gdx.files.internal("data/texSpriteBatchTest.png"));

    squareMesh = new Mesh(true, 4, 4, 
            new VertexAttribute(Usage.Position, 3, "a_position")
            ,new VertexAttribute(Usage.TextureCoordinates, 2, "a_texCoords")

    );

    squareMesh.setVertices(new float[] {
            squareXInitial, squareYInitial, squareZInitial,             0,1,    //lower left
            squareXInitial+squareSize, squareYInitial, squareZInitial,  1,1,    //lower right
            squareXInitial, squareYInitial+squareSize, squareZInitial,  0,0,    //upper left
            squareXInitial+squareSize, squareYInitial+squareSize, squareZInitial,1,0});  //upper right 

    squareMesh.setIndices(new short[] { 0, 1, 2, 3});

    spriteBatch = new SpriteBatch();        
}

.

和render（）方法：

public void render() {
    GLCommon gl = Gdx.gl;

    camera.update();
    camera.apply(Gdx.gl10);
    spriteBatch.setProjectionMatrix(camera.combined);

    gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    gl.glEnable(GL10.GL_DEPTH_TEST);

    gl.glEnable(GL10.GL_TEXTURE_2D);
    textureMesh.bind();
    squareMesh.render(GL10.GL_TRIANGLE_STRIP, 0, 4);

    spriteBatch.begin();
    spriteBatch.draw(textureSpriteBatch, -10, 0);
    spriteBatch.end();        
}

.

现在，如果在我的调整大小（int宽度，int height）方法中，我将相机设置如下：

   public void resize(int width, int height) {
        float aspectRatio = (float) width / (float) height;
        camera = new OrthographicCamera(cameraViewHeight * aspectRatio, cameraViewHeight);

.

我得到这个：

但如果我更改相机类型：

public void resize(int width, int height) {
    float aspectRatio = (float) width / (float) height;
    camera = new PerspectiveCamera(64, cameraViewHeight * aspectRatio, cameraViewHeight);
}       

.

我得到这个：

我要问的原因是因为我真的很喜欢Libgdx的内置能力绘制OpenGL中的文本（字体）。但在他们的例子中，他们使用他们向字体实例路径的SpriteBatch，它们也始终使用Ortho相机。如果SpriteBatch和字体绘制功能与PerspectivCamera一起工作，我想知道。

Answer 1

嗯，好的，我解决了它：

简短答案：

Spritebatch在内部使用正交性。如果使用perspectivecamera，则需要将自定义视图矩阵传递到Sprepitebatch。您可以在调整大小（...）方法中执行此操作：

@Override
public void resize(int width, int height) {
    float aspectRatio = (float) width / (float) height;
    camera = new PerspectiveCamera(64, cameraViewHeight * aspectRatio, cameraViewHeight);
    viewMatrix = new Matrix4();
    viewMatrix.setToOrtho2D(0, 0,width, height);
    spriteBatch.setProjectionMatrix(viewMatrix);
}

.

然后没有必要使用该精灵的投影矩阵（除非您想改变Sprite在屏幕上显示的方式），

public void render() {
    GLCommon gl = Gdx.gl;

    camera.update();
    camera.apply(Gdx.gl10);
    //this is no longer needed:
    //spriteBatch.setProjectionMatrix(camera.combined);
    //...

.

长答：由于我的最终目标是能够使用sprepitebatch来绘制文本，而在上面提到的修改到我的代码我可以做到这一点，从某种意义上是Sprite上的文本和网格上的文本纹理现在可见，我注意到，如果我没有为我的网格的顶点指定颜色，则所述顶点将获得我用于文本的颜色。换句话说，纹理网格如下所示：

 squareMesh = new Mesh(true, 4, 4, 
            new VertexAttribute(Usage.Position, 3, "a_position")
            ,new VertexAttribute(Usage.TextureCoordinates, 2, "a_texCoords")

    );

    squareMesh.setVertices(new float[] {
            squareXInitial, squareYInitial, squareZInitial,             0,1,    //lower left
            squareXInitial+squareSize, squareYInitial, squareZInitial,  1,1,    //lower right
            squareXInitial, squareYInitial+squareSize, squareZInitial,  0,0,    //upper left
            squareXInitial+squareSize, squareYInitial+squareSize, squareZInitial,1,0});  //upper right 

    squareMesh.setIndices(new short[] { 0, 1, 2, 3});

.

在我的渲染（...）方法中也有此代码将使网格红色：

font.setColor(Color.RED);
spriteBatch.draw(textureSpriteBatch, 0, 0);
font.draw(spriteBatch, (int)fps+" fps", 0, 100);

.

此方法是从开始时将颜色设置在网格顶点上：

squareMesh = new Mesh(true, 4, 4, 
        new VertexAttribute(Usage.Position, 3, "a_position")
        ,new VertexAttribute(Usage.ColorPacked, 4, "a_color")
        ,new VertexAttribute(Usage.TextureCoordinates, 2, "a_texCoords")

);

squareMesh.setVertices(new float[] {
        squareXInitial, squareYInitial, squareZInitial,                         Color.toFloatBits(255, 255, 255, 255),  0,1,    //lower left
        squareXInitial+squareSize, squareYInitial, squareZInitial,              Color.toFloatBits(255, 255, 255, 255),  1,1,    //lower right
        squareXInitial, squareYInitial+squareSize, squareZInitial,              Color.toFloatBits(255, 255, 255, 255),  0,0,    //upper left
        squareXInitial+squareSize, squareYInitial+squareSize, squareZInitial,   Color.toFloatBits(255, 255, 255, 255),  1,0});  //upper right 

squareMesh.setIndices(new short[] { 0, 1, 2, 3});

.