Placement of Sprite3D goes different on different devices cocos2d-x

cocos2d-x C++
1

I am working on the game project having a Sprite3D as a base ground and all other will be placed over it, but It’s placement is different on different devices.
Here is my code

float zeye = Director::getInstance()->getZEye();

m_table = Sprite3D::create(“GR_Table_Base_v2.c3b”);
m_table->setPosition3D(Vec3(0,0, zeye * 0.8f));
m_container->addChild(m_table);
m_table->setTag(kTableTag);

How can I calculate the zPosition perfectly ?

float zeye = Director::getInstance()->getZEye();
gives different values with different devices and that why making the Sprite3D object visibility ambiguous.