[FifteenPen]

What and why

In Nintendo Switch Sports Resort (04008E001F098000, v65536), characters' outfits are black in the menus (Customize, Select User) and right in play. Skin, face and hair are lit either way.

Cause. The menu scene blurs its screen-space shadow target back and forth between two 2048x1152 targets. From one frame's records:

chmask bind 0xfffffff6            (slot 0: G and B)
clear slot0 own mask 0xf          then a blur draw, wm=0xfffffff6      x7, alternating the two targets
chmask bind 0xffffffff

• A pass before the blurs writes all four channels of the target.
• The material shader c30f0edd6c669a61 samples the target through a view swizzle of (G, A, B, R), takes .xyw, and multiplies its lighting by them. So it reads the target's G, A and R.
• The host cleared by the clear's own mask alone, so R and A were 0 from the first blur on, and the lighting came out 0.
• In play the target is written once, with no blur, so nothing was lost.
• The skin shader binds a white 4x4 texture in that slot, which is why skin stayed lit.

Measured in the outfit's own draw, with a debug copy of its pixel shader that paints the sampled channels as threshold-coded stripes:

Channel of the target	Menu	Golf round
A	< 0.02	≥ 0.75
R	< 0.02	≥ 0.75
min(R, 1), the light factor	< 0.02	≥ 0.75

The lights were there in the menu: the light loop ran, the cluster held about 3 lights, and the environment cube had data.

Fix. Under a channel mask state that lets only some of the target's channels through, a colour clear writes its own mask's channels among those (clear_mask in nvn_mtl.m). It is drawn as a triangle with that mask, like the existing partial-mask clears. The scans that plan passes ahead of the replay (sdx_walk, hoist_try, fuse_try) follow the state's binds as they follow the scissor, so such a clear is not taken for one that replaces the target's content.

What this does not settle. With every channel of the target off, the clear stays whole, as on main. I first made the clear follow the state in every case, and that broke the same game: it clears its main colour target right after a shadow pass drawn with the mask at 0 (clear slot0 own mask 0xf state 0), and with that clear held back the Select User background came out black with outlines. I don't know what a console does under a mask of 0. This is the narrowest rule both cases bear out: it changes main's behaviour only where a game has masked off some channels but not all. The reference entry says so under Open.

Checked

• check_t_clear_chmask (new, GPU, 35 checks). On main (6a6a018) cases 1, 2, 3 and 5 fail; with the change all pass:
  • a clear under a mask of G and B keeps R and A, from the state or from a bind in the same records;
  • the clear's own mask and the state's combine;
  • a mask of nothing leaves the clear whole;
  • another target's mask does not count.
• The other clear tests pass: check_t_clear_layers (30), check_t_clear_ds (59), check_t_clear_msaa (32), check_t_clear_tex (51).
• check_t_geometry (1,929) and check_t_copy_alias (126) pass.
• test_docs.py and the symptom index pass.
• lint_c.py tidy: nothing new. The four file/check pairs above the baseline are in t_blend_zero.m, t_clear_msaa.m, t_mip_extent.m and t_pso_archive.m, none of which this touches.
• The game (M4 Pro, macOS 27.2): outfits are lit on Customize and Select User, and Select User's background is right. That run was on a tree with this change plus the game's other open PRs; it does not boot on main alone.

Not checked

• Other games. Any game that clears under a partial channel mask now keeps the masked channels; none was run.
• What a console does with a clear under a channel mask of 0 (above).

The game's profile is in #2107.

[seedds]

Thanks for the careful measurement: the outfit material reading 0 from R and A of the blurred shadow target is right, and it is in the game's note. The cause is earlier, though: the game wraps those draws in render conditions, and the host drew them anyway. With the profile's render_cond on and without this change, Select User shows the court behind the player and the outfits are lit, on the same route from the same save (A/B on an M6); that also explains why following the channel mask everywhere blackened the background. What a console does with a clear under a channel mask is not in the game's files (its nvnCommandBufferClearColor jumps through a pointer the system's NVN driver fills), so the narrower rule is not landed. The profile with render_cond landed as f4b7e77.