Emulator

Game Name?

Super Mario Galaxy 2

Game ID? (right click the game in the game list, properties, info tab)

SB4E01

MD5 Hash? (right click the game in the game list, properties, info tab, MD5 Hash: Compute)

9e1774f27e2521b8c80e2dde38d28b03

What's the problem? Describe what went wrong.

Problem noticed after updating to 5755. In World #1, where the surrounding sky is blue and cloudy, if you look at the skybox or even the planet underneath, there are seam lines delineating the triangles that make up the background. I have narrowed down the issue to MSAA and happens regardless of internal resolution being rendered. This does not happen without AA or when using SSAA. The problem was present on the previous version I was using (r5636) but was much less noticeable because the bright center portion of the skybox was compressed due to the mipmap issue that was recently corrected (October progress report). I suspect the new mipmap code that fixes the skybox makes the issue more obvious.

You can see some comparisons below:
Skybox 3xIR 4xMSAA r5636 - Issue present close to the light band in the middle but not very noticeable:
https://imgur.com/kiiuJCJ

Skybox 3xIR 4xMSAA r5755 - Issue present and much more noticeable:
https://imgur.com/xGlNOId

Save Select 3xIR 4xMSAA r5755 - Issue present but a bit hard to see in screenshot:
https://imgur.com/dlSJmqb

Save Select 3xIR NO AA r5755 - Issue not present without AA:
https://imgur.com/tDFtP7T

What steps will reproduce the problem?

1. Set 4xMSAA on D3D11 at any resolution (tested at native and 3x)

Is the issue present in the latest development version? For future reference, please also write down the version number of the latest development version.

Yes: as of 5763

Is the issue present in the latest stable version?

Yes (5.0).

If the issue isn't present in the latest stable version, which is the first broken version? (You can find the first broken version by bisecting. Windows users can use the tool https://forums.dolphin-emu.org/Thread-green-notice-development-thread-unofficial-dolphin-bisection-tool-for-finding-broken-builds and anyone who is building Dolphin on their own can use git bisect.)

I even tested versions as old as 4.0-378 and the issue is there so it appears to have gone unnoticed because the mipmap issue made the clouds cover up the problem.

If your issue is a graphical issue, please attach screenshots and record a three frame fifolog of the issue if possible. Screenshots showing what it is supposed to look like from either console or older builds of Dolphin will help too. For more information on how to use the fifoplayer, please check here: https://wiki.dolphin-emu.org/index.php?title=FifoPlayer

Pictures linked above.

What are your PC specifications? (CPU, GPU, Operating System, more)

Windows 10 Pro x64 | Intel Pentium G3258 @ 4.2 GHz (stock cooler) | MSI PC Mate Z97 MB | AMD R9 280 (MSI PC Gaming 3G) | 8 GB DDR3-1600

Is there anything else that can help developers narrow down the issue? (e.g. logs, screenshots,
configuration files, savefiles, savestates)

Simply using 4xMSAA makes the issue evident. First I though it was caused by the mipmap fix but now I realize it was there already and the fix just made it more visible.