Does HoloLens support DirectX 12?

Dwight_Goins_EE_MVP

Please read before you give the documented answer...

I just built a directx 12 C++ project template and pushed it to the HoloLens. It ran just fine. I cracked open the code and it is indeed using DirectX 12. It's linked to the d3d12.lib and everything. Now I know it's also a 2D Window with a 3D Swap chain, however it's built with the DirectX12 libraries. So the logical question is what gives???

The write up says DirectX 11 support not DirectX 12

Dwight_Goins_EE_MVP

Ok, so I just checked and currently the supported Feature Level that's working on my HoloLens build is 11_1. But the DirectX 12 libraries, classes, adapters and interfaces work just fine:

HRESULT hr = D3D12CreateDevice(
        adapter.Get(),                  // The hardware adapter.
        D3D_FEATURE_LEVEL_11_1,         // Minimum feature level this app can support.
        IID_PPV_ARGS(&m_d3dDevice)      // Returns the Direct3D device created.
        );

The above code works.

AmerAmer

Interesting. What feature level is turned on on the when creating the device? Maybe it defaulted back to 11.1? Did it actually run on the device? I tested this with the emulator and it reverts back to warp with D3D_FEATURE_LEVEL_11_0 when it fails to creating the D3D12Device

Dwight_Goins_EE_MVP

I'm not able to test the create device call at this present moment on live device. However that's a good and obvious point.

I feel that ...Duh... moment.... 

I assumed DirectX 12, because all of the DX12 classes, D12 Descriptiors, D3D12InputElements, Resources, Heap, PipelineState, and etc all using DX12. I guess I need to read some more on the DX12 features.

Thanks. I'll check as soon as I can and report back here.

mlfarrell

I'd be very interested to know how this goes. I have built a Dx12 backend for my engine awhile back but don't have 11, so I've had to rely on angle for my OpenGL renderer for the time being.

AmerAmer

Tomorrow when I get back to my office I'll try to load up a DX12 version of the spinning cube to a commercial device to see what happens. I'll either remove the revert to warp or output the HResult of the createDevice function call.

Dwight_Goins_EE_MVP

Ok, so I just checked and currently the supported Feature Level that's working on my HoloLens build is 11_1. But the DirectX 12 libraries, classes, adapters and interfaces work just fine:

HRESULT hr = D3D12CreateDevice(
        adapter.Get(),                  // The hardware adapter.
        D3D_FEATURE_LEVEL_11_1,         // Minimum feature level this app can support.
        IID_PPV_ARGS(&m_d3dDevice)      // Returns the Direct3D device created.
        );

The above code works.