在我的渲染器中，我有：
private float[] MATRIX_VIEW = new float[16];
private float[] MATRIX_PROJECTION = new float[16];
private float[] MATRIX_VP = new float[16];
在“onSurfaceChanged”中：
...
//Set projection
Matrix.orthoM(
MATRIX_PROJECTION,0,
-hDim,hDim,
-vDim,vDim,
1,100
);
//Set View
Matrix.setLookAtM(
MATRIX_VIEW,0,
cameraPosition[0],
cameraPosition[1],
cameraPosition[2],
cameraFacing[0],
cameraFacing[1],
cameraFacing[2],
cameraHook[0],
cameraHook[1],
cameraHOOK[2]
);
//SetView*Projection
Matrix.multiplyMM(
MATRIX_VP,0,
MATRIX_PROJECTION,0,
MATRIX_VIEW,0
);
...
我有一个形状的许多克隆，所以我编写了“ShapeSet_Set”类：
...
private float[] MATRIX_ORIGIN = new float[16];
private float[] MATRIX_VPO = new float[16];
private float[] MATRIX_SCALE = new float[16];
...
/*
origin matrix is group of all shapes center position
scale matrix represents zoom
*/
和“ShapeSet_Element”：
...
private float[] MATRIX_POSITION = new float[16];
private float[] MATRIX_ROTATION = new float[16];
private float[] MATRIX_ALL = new float[16];
...
/*
position matrix is position of shape relative to origin position
rotation matrix is shape rotation arond its center
all matrix is matrix which will be passed to shader
*/
在渲染器的“DrawFrame”上，ShapeSet_Set 的“onDrawFrame”被调用。它计算 View*Projection*Origin 矩阵：
...
Matrix.multiplyMM(
MATRIX_VPO,0,
RENDERER.getVPMatrix(),0,
MATRIX_ORIGIN,0
);
...
并调用每个 ShapeSet_Element 的“onDrawFrame”，其中包含：
...
//Get View*Projection*Origin matrix
System.arraycopy(
SET.getVPOMatrix(),0,
MATRIX_ALL,0,
16
);
//Apply zoom
Matrix.multiplyMM(
MATRIX_ALL,0,
MATRIX_ALL,0,
SET.getScaleMatrix(),0
);
//Apply element's position
Matrix.multiplyMM(
MATRIX_ALL,0,
MATRIX_ALL,0,
MATRIX_POSITION,0
);
//Apply element's rotation
Matrix.multiplyMM(
MATRIX_ALL,0,
MATRIX_ALL,0,
MATRIX_ROTATION,0
);
...
一切正常，直到我应用旋转。这是设置元素旋转的方法：
public void setRotation(float xDeg,float yDeg,float zDeg)
{
//Set new rotation values to open up actual values
rotation_X = xDeg;
rotation_Y = yDeg;
rotation_Z = zDeg;
//Set new rotation matrix
Matrix.setIdentityM(MATRIX_ROTATION,0);
//Rotate around x axis
Matrix.rotateM(
MATRIX_ROTATION,0,
rotation_X,0,
1,0,0
);
//Rotate around y axis
Matrix.rotateM(
MATRIX_ROTATION,0,
-rotation_Y,0,
0,1,0
);
//Rotate around z axis
Matrix.rotateM(
MATRIX_ROTATION,0,
rotation_Z,0,
0,0,-1
);
}
当元素围绕 x 或 y 轴旋转时，它可以正常工作，但是......当围绕 z 轴旋转时，元素的高度（原始 y 尺寸）在几何上减小到 0，当旋转 90 度并在旋转 180 时放大到原始值度。
有谁知道，这可能是什么原因？
如果这是通过错误的矩阵乘法或错误的旋转矩阵设置完成的，我无法解决。