can any one point me how i can generated object in the game at run time

can any one point me how i can generated object in the game at run time the object it self not on the items in content browser its say cube i make within the code??
can any one point me to that
as well can i work with opengl within the game (have a lib i need work with for a game i make) if so how?

Well its not easy.First you need to create a vertex and index buffer.You need to provide all 8 vertex ( cube ) and 36 indices in order to render engine appropiately draw it.Its not the good way to draw things especially you have a powerful editor…

https://docs.unrealengine.com/latest/INT/API/Runtime/RenderCore/index.html

you can check this link for further info but as I said if you’re not familiar with some D3D11 basic rendering pipeline stuff you’re gonna have hard time implementing that.

then let me ask different approach how i can apply on a mesh heightmap say the mesh its self i will premade???