Greetings,

I am having some issues with my deferred shading implementation that I am spinning my tires on.

The back buffer format I am using is:

DXGI_FORMAT_R8G8B8A8_UNORM.

My GBuffer render targets are:

I know some the rgba32_f textures may be overkill, but I'm just trying to get things working before worrying about saving too much on bandwidth and other similar concerns - with such simple scenes (one sphere and a plane for the ground, oh my!) there's not too much performance impact .

Here is an example of what is going on.

[attachment=14417:ugly banding r8g8b8a8_unorm_bbuffer.PNG]

Any insight to possible fixes I may have missed would be greatly appreciated. I may be missing something obvious, and have just been staring at it for too long. If there is any other information I can supply to better troubleshoot this issue, just let me know.

Thanks!

Indeed, that seems to be just the unavoidable banding you always with such a slowly changing gradient and current monitors. Another thing you can do is apply some very slight noise, it won't be visible as noise but will smooth out the gradient.

liprsyme: Yes, I should have mentioned it, but the texture I'm using for the floor plane is just a 1 x 1 pixel white texture that's just tiled over the entire thing. The texture's format is X8R8G8B8, but I also tried just a few moments ago changing that to A16G16B16R16F just to see if it would help. It did not.

AgentC: Interesting. What about the fact that the bands are still there when using the DXGI_FORMAT_R16G16B16A16_FLOAT back buffer format? I've posted a picture. Please disregard the non-gamma-correctedness of it (it's automatically put into linear color space, see here http://msdn.microsoft.com/en-us/library/windows/desktop/ff471325(v=vs.85).aspx). At this point, is it basically just the fact that the monitor is incapable of producing a colors between those banded values? By the way, you're right - the image is produced identically when I switch to the forward renderer.

powly k: That's a good idea, I may try that out if it turns out to be strictly a monitor-related issue.

Editted to include image and forward rendering comment.

lipsryme: OK, I see what you were saying now, and yes using a "real" texture does alleviate the problem (for example the sphere in the first picture I posted doesn't have an issue). I was just making sure I wasn't doing something incorrectly elsewhere to cause the bands, but it definitely looks to be monitor limitations.

Thank you and all others who posted for your help with this!

Of course there is going to be banding. Using a 16-bit back buffer isn't going to make any difference since it's still going to get quantized to 8-bit when being displayed. You would have to render to a HDR buffer and then perform some type of dithering operation when converting to 8-bit LDR for display.

As far as I know A2R10G10B10 format is supported in full screen modes and should give less banding if your monitor supports more than 8-bits per channel. DX SDK even had a sample about it.

The problem you are describing is difficult to handle, but typically you won't notice the problem since most of the surfaces are textured and texturing hides the problem pretty well.

Cheers!