DirectX11 Non-Solid wireframe

Question

I'm attempting to draw a 100x100 grid in DirectX11 using C++, but the following issue happens:

The image above shows a grid I am drawing in wireframe, using a rasterizer with its fillmode set to 'D3D11_FILL_WIREFRAME' and a 'D3D11_PRIMITIVE_TOPOLOGY_LINELIST' topology. The lines of the wireframe appear staggered rather than straight, with some parts of the wireframe missing.

As I'm not sure what this issue is referred to as, I'm not entirely sure what I should be looking for and as such, any help is appreciated.

Chuck Walbourn · Answer 1 · 2015-11-13T06:32:08.237

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This is a classic problem of 'aliasing'.

With Direct3D 11, you can use either MSAA which is a general anti-aliasing option, or use a specific line algorithm if you are not using MSAA. See D3D11_RASTERIZER_DESC AntialiasedLineEnable and MultisampleEnable.

See Aliasing and Multisample anti-aliasing

UPDATE: I've added MSAA and the AA mode to the DirectX Tool Kit tutorial.

edited Nov 13 '15 at 06:32

answered Nov 09 '15 at 02:37

Chuck Walbourn

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My rasterizer_desc has the AntialiasedLineEnable and MultisampleEnable flags set already, but doesn't seem to make a difference – BoyUnderTheMoon Nov 10 '15 at 10:05
But are you using a MSAA render target/backbuffer? – Chuck Walbourn Nov 10 '15 at 19:08
Yes, the Count settings of the descriptions are set correctly – BoyUnderTheMoon Nov 11 '15 at 00:24
What feature level is your device? Try out the four possible combinations of ``AntialiasedLineEnable`` and ``MultisampleEnable``. – Chuck Walbourn Nov 11 '15 at 18:14

score 0 · Answer 2 · answered Nov 13 '15 at 01:58

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I stumbled across the solution to this and it wasn't what I expected at all. Since the window I created had outline bars, the windows client area was being misrepresented. So when I was creating my graphics device, I was initializing it with the windows size, rather than the windows client size. Somehow, this caused the issue above.

I fixed this by implementing a 'GetClientSize' method for the window, using 'GetWindowRect'.

answered Nov 13 '15 at 01:58

BoyUnderTheMoon

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Ah, yes, if the backbuffer isn't matching the window target size, you will get somewhat 'squashed' results. I verified that if you use a MSAA 4X backbuffer and then use ``D3D11_RASTERIZER_DESC.MultisampleEnable= TRUE`` you will get AA lines, and without MSAA you get AA lines if you use ``D3D11_RASTERIZER_DESC .AntialiasedLineEnable = TRUE`` – Chuck Walbourn Nov 13 '15 at 05:28

DirectX11 Non-Solid wireframe

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