title: frustumM / setLookAtM in OpenGL ES 2.0 on Android
body: <p>I am playing around with OpenGL on the Android platform using the OpenGL ES 2.0 tutorial as a basis. The code in question is:</p>
  
  <pre><code>public void onSurfaceChanged( GL10 unused, int width, int height )
  {   GLES20.glViewport( 0, 0, width, height );
  
      float ratio = (float) width / height;
      Matrix.frustumM( mProjMatrix, 0, -ratio, ratio, -1, 1, 1,  9.9999f );
  
      Matrix.setLookAtM( mVMatrix, 0, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f,  0.0f, 0.0f, 1.0f,  0.0f );
  
      muMVPMatrixHandle = GLES20.glGetUniformLocation( mProgram, "uMVPMatrix" );
  }
  </code></pre>
  
  <p>In particular, the "far" parameter to frustumM. Whenever that parameter is 10 the image (a triangle) does not appear. Any other value is OK. Why?</p>
  
  <p>I have done a fair bit of reading - all to no avail. Even my friend (aka Google) has not been able to help me.</p>
  
  <p>Thanks in advance.</p>