Hi,

I have multisampled rendertarget where I use red channel as some sort stencil data, but the problem is I get incorrect results around borders if "Antialiasing - Gamma Correction" is set to on in Nvidia Control Panel. Is there a way to turn that off while I am writing to that specific render target (if user has it enabled in graphics card's control panel)?

Edit: screenshots
Antialiasing - Gamma Correction set to

On
http://i.cubeupload.com/stXIKw.png

Off

http://i.cubeupload.com/QaCO9K.png

While creating these two screenshot I noticed that artifacts caused by gamma correction are also visible in other areas. Like in background text. Text is outlined when gamma correction is on (but should not be). Text is not rendered with bitmap font, but as vector shapes.

What texture format are you using for your render target?

Cheers!

32-bit ARGB pixel format with alpha, using 8 bits per channel.

Is it a format with _SRGB ending?

[edit]If you need only one channel, you could use either DXGI_FORMAT_A8_UNORM format or store the data in the alpha component. Typically the alpha component isn't affected by gamma correction.

Cheers!

I don't know. I am using XNA framework and I am not sure which exact underlying D3D surface it uses. Here is the full list of supported surfaces: SurfaceFormat Enumeration (I'm using Color surface).

I tried setting SRGBWriteEnable to false in shader as described here, but I get compiler error that it is obsolete.

However the plan is to migrate whole project to MonoGame after it is feature complete (MonoGame acts as drop in replacement for XNA). So even if correcting this might not be possible in pure XNA, any hack for MonoGame would be OK too.

Edit: Two channels are needed. One contains alpha override data and the other stencil mask that specifies where alpha override gets applied. Stencil mask is written to red channel and alpha override to alpha channel.

I'm trying to limit what graphic features are used to XNA's Reach profile, so that porting mobile platforms would be easier later on. (Or at least have an alternative renderpath that for Reach profile.)
Reach profile's texture formats are: Color, Bgr565, Bgra5551, Bgra4444, NormalizedByte2, NormalizedByte4, Dxt1, Dxt3, Dxt5

Can Nvidia's override be controlled/disabled?

Border appears around stencil masked shape not around full screen quad. This happens only when "Antialiasing - Gamma Correction" is set to on. If its turned off it renders correctly. I will post screenshots with that setting turned on and off. I tired creating device with PreferMultisampling false and multisampled render targets. The problem still persists. My guess is that artifacts are caused because I save stencil data into red channel which is being gamma corrected around stencil shape's edges (stencil mask is created by rendering 2D vector shape into multisampled render target).

Which driver version are you using. It doesn't say that it only affects OpenGL programs in the version I have installed, that's v331.93. Maybe they changed description? Researching the subject I found this forum thread, where OP claims that description in Nvidia control panel is false because Antialiasing - Gamma Correction option also affects Direct3D games like Half-Life 2 and Call of Duty.