Use HIVs debugging tools. On AMD cards GPUPerfstrudio and CodeXL have a pretty nice D3D12 support, intel GPA support is in alpha but better than nothing, while nvidia nsight support isn't that great now..

It's the shame of Microsoft the first party lagging behind its followers.

http://zerotutorials.com/DirectX12/Tutorial04

You can definitely debug the shaders, I do it all the time in d3d12 and it's pretty amazing. Once you open graphics diagnostics from debug menu, capture a frame by clicking capture or print screen. Next double click that frame and then go to view pipeline. Once in the pipeline view there will be a play button under the vertex shader view and a play button under the pixel shader view. You can also play each individual vertex by clicking the play button next to the vertex you want to debug through the shader.

http://zerotutorials.com/DirectX12/Tutorial04

You can definitely debug the shaders, I do it all the time in d3d12 and it's pretty amazing. Once you open graphics diagnostics from debug menu, capture a frame by clicking capture or print screen. Next double click that frame and then go to view pipeline. Once in the pipeline view there will be a play button under the vertex shader view and a play button under the pixel shader view. You can also play each individual vertex by clicking the play button next to the vertex you want to debug through the shader.

Well, I probably realized what you said, as I may have been wrong. The "only support DX11" error message may not come from the sheet for shader debugging (well the UI looks extremely complex).

However one thing I still want to know is, when I debug a VS code, with the draw() call with say 6 vertices, but in the code we can just debug it with the first vertex, seems no way to jump to the execution with other vertices?

First open graphics pipeline