Texture scroll and alpha fades

Sekiro can transform texture coordinates in the vertex stage and animate UVs inside the material program. Alpha testing and camera fades are also shader operations, rather than a fixed-function alpha-test state. Observed

Vertex coordinate transforms

cbTexScroll holds VC_TexScroll_0 through _3, with per-set scale in XY and offset in ZW. The inspected programs compute uv = storedShortUV/2048 * scroll.xy + scroll.zw; layered programs use sets 0 and 1, while the inspected GXFlver programs use set 0. Observed

The block occurs in 2,189 of 2,824 inspected GXFlver vertex programs. In the available castle capture, all 40,744 layered draws it logged (at most 800 a frame) have identity texture-scroll constants. Outdoors in Ashina every layered draw of 460 consecutive frames (384,131 draws) has the same four [1,1,0,0] vectors. This does not establish identity on water and other time-dependent families. Observed In the running game, raising the first vector to [8,8,0,0] for the draws of one layered program makes their textures repeat far more finely, so the first two components scale the coordinates as the formula has it (runtime render state). Observed · one frame each way

Smithbox names GX20 through GX34 as per-texture-type U/V scroll speeds with a further float, and GX07 as a water-related record. Sourced · Smithbox

The whole-install GX scan records nonzero scroll data only on the inspected M[A]_al map pieces, a river’s GX20 and GX26 items, and a water material’s GX07. No layered material in that scan carries a scroll item. Observed The specific rule offset = speed*time remains an inference without a capture of those moving surfaces. Inferred

The scan covers the install’s 14,459 FLVERs and 43,435 materials. Twelve items on four map pieces (and their _S twins where listed) carry nonzero values; layered materials carry only GX00 and GX04 items. Observed · Sekiro

Map piece	Material	Items	Confidence
m25_00_00_00_906000 and _S	M[A]_al	GX20, V −0.03 and −0.05	Observed · Sekiro
m17_00_00_00_106000 and _S	M[A]_al_NoLight	GX20, 0.005 and 0.005	Observed · Sekiro
m20_00_00_00_920000, a river	M[ARSN]	GX20 (0, −0.08); GX26 (0, −0.04)	Observed · Sekiro
m25_00_00_00_300010	M[ARSN]_Water_3normaltet	GX07	Observed · Sekiro

M[Flow]_Water and Character_AMSN_Scroll* instead multiply MTD float2 parameters by FC_GlobalTime inside their material programs. Observed

Alpha and fade inputs

Inspected alpha-tested programs discard when a tested alpha is below FC_AlphaRef.x. Some perturb the tested scalar with (ditherAlpha - 0.5) * FC_AlphaRef.y before comparison. Setting the dither sample to 0.5 removes that perturbation for finite scale, but does not describe the runtime noise texture. Observed

The alpha-test permutation can also read FC_isDitherAlpha, FC_DitherEnable and FC_isEnableCameraDitherFade, plus camera fade range constants. In the 11,252 captured _Gbuf_[A] draws, the camera-fade flag and FC_isDitherAlpha are always zero; FC_DitherEnable is one on 99 draws and zero on the rest. A set enable word alone therefore does not prove an active fade. Observed

Sekiro’s Ashina Castle frames draw 19 meshes whose materials carry GX20 scroll records (GX20, GX22, GX24 and GX26 together on the M[ARSN] ones, GX14 and GX20 on three M[A]), and every one uploads the identity cbTexScroll. Observed[one frame; 859 draws with the block]{games=“sekiro”} The record’s payload is not in a capture, so whether those authored speeds are zero was not read; the whole-install scan above finds nonzero values only on four map pieces, none of them among these. Inferred · Sekiro Elden Ring’s cbTexScroll is the identity in all 4,325 draws that bind it in five Stormveil sessions, among them the M[Water][ocean4] and M[Water][ocean_Horizon] water draws, whose pixel and domain programs read FC_GlobalTime: the ocean’s motion comes from the program’s time, not from a scroll upload. Observed · Elden Ring · five captures

Moving surfaces that do not use cbTexScroll carry their motion in other constants. Sekiro’s effect-water pixel program (PSCommonBuffer) takes g_vNormalMapScrollDistance and g_hNormalMapScrollDistance in c6.xy: three draws per frame, each pair different (for example 0.6185 and 0.8765 in one draw, 0.628 and 14.79 in the next) and different again in each of six sessions at the same spot. Observed[six Sekiro frames of one spot]{games=“sekiro”} A value that changes between sessions is not a material value, so the game writes it at run time. Inferred · Sekiro Elden Ring’s fog volumes carry scrollSpeed and scrollScale in cbRendering.g_renderingDensity (for example speed (0.2, -0.05, 0.3) on one volume and (0, -4, -10) on the others), not in a material buffer. Observed · Elden Ring

Which GX values generate each scroll constant?

No captured frame holds a surface with a nonzero authored GX scroll: every cbTexScroll of Sekiro and Elden Ring frames is the identity, so the upload rule, the time origin and the meaning of each extra float are still not shown. A frame of a river or the water material GX07 describes (the whole-install scan names m20_00_00_00_920000 and m25_00_00_00_300010), ideally two frames about a second apart, would decide it. Unknown