Ubuntu – Kernel drive in use is not Nvidia

I am trying to install NVidia drivers on Linux mg-Ubuntu 3.16.0-45-generic #60~14.04.1-Ubuntu . Here is screen shot from GTK;

And also in here is from Nvidia settings;

However when I tried to use Unreal Engine 4 in my Ubuntu graphics are not good. There are lots of weird colors are appearing. Here is image from Unreal Engine;

Then I go and check lspci and glxinfo whether my nvidia is working correctly or not. And it says that Kernel driver in use: i915

mg@mg-Ubuntu:/.1/Programs/UnrealEngine/UnrealEngine-release/Engine/Binaries/Linux$ lspci -vnn | grep -i VGA -A 1200:02.0 VGA compatible controller [0300]: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09) (prog-if 00 [VGA controller])
    Subsystem: Lenovo Device [17aa:3912]
    Flags: bus master, fast devsel, latency 0, IRQ 45
    Memory at d3000000 (64-bit, non-prefetchable) [size=4M]
    Memory at e0000000 (64-bit, prefetchable) [size=256M]
    I/O ports at 4000 [size=64]
    Expansion ROM at <unassigned> [disabled]
    Capabilities: <access denied>
    Kernel driver in use: i915

00:14.0 USB controller [0c03]: Intel Corporation 7 Series/C210 Series Chipset Family USB xHCI Host Controller [8086:1e31] (rev 04) (prog-if 30 [XHCI])
    Subsystem: Lenovo Device [17aa:3977]
    Flags: bus master, medium devsel, latency 0, IRQ 41

However OpenGL renderer is GeForce not MESA

mg@mg-Ubuntu:/.1/Programs/UnrealEngine/UnrealEngine-release/Engine/Binaries/Linux$ glxinfo | grep OpenGL | grep renderer
OpenGL renderer string: GeForce GT 720M/PCIe/SSE2

How can I solve this issue? Why lspci is saying that Kernel drive is i915?