diff --git a/crates/gc-engine/src/main.rs b/crates/gc-engine/src/main.rs
index 72b0480..77aa541 100644
--- a/crates/gc-engine/src/main.rs
+++ b/crates/gc-engine/src/main.rs
@@ -19,7 +19,7 @@ use std::path::PathBuf;
 
 use anyhow::{Context, Result};
 use bevy::asset::RenderAssetUsages;
-use bevy::image::{ImageFilterMode, ImageSampler, ImageSamplerDescriptor};
+use bevy::image::{ImageAddressMode, ImageFilterMode, ImageSampler, ImageSamplerDescriptor};
 use bevy::prelude::*;
 use bevy::render::mesh::{Indices, PrimitiveTopology};
 use bevy::render::render_resource::{Extent3d, TextureDimension, TextureFormat};
@@ -386,11 +386,20 @@ fn image_of(t: &gc_formats::texture::Texture) -> Image {
         TextureFormat::Rgba8UnormSrgb,
         RenderAssetUsages::default(),
     );
-    // Only mip level 0 is decoded, so minification must clamp rather than
-    // invent a level the disc does not have here.
+    // The GS clamps; bevy's default is Repeat. This was `..default()` with a
+    // comment claiming the sampler clamped, which it did not -- the default is
+    // ImageAddressMode::Repeat. A tile edge therefore wrapped onto its opposite
+    // edge instead of repeating the border texel, which is the seam you see when
+    // a patch runs off its texture. See gc_formats::gs::clamp01.
+    //
+    // Only mip level 0 is decoded, so there is no chain to interpolate: the
+    // mipmap filter is Nearest because it samples that single level either way,
+    // and gs::mip_level would return 0 for every patch until levels are decoded.
     image.sampler = ImageSampler::Descriptor(ImageSamplerDescriptor {
         label: Some("tfrag texture".into()),
-        mipmap_filter: ImageFilterMode::Linear,
+        address_mode_u: ImageAddressMode::ClampToEdge,
+        address_mode_v: ImageAddressMode::ClampToEdge,
+        mipmap_filter: ImageFilterMode::Nearest,
         mag_filter: ImageFilterMode::Linear,
         ..default()
     });
diff --git a/docs/roadmap.md b/docs/roadmap.md
index ad7d32f..3f2f2e3 100644
--- a/docs/roadmap.md
+++ b/docs/roadmap.md
@@ -717,9 +717,11 @@ lookup, and it is the main thing inherited from ReRAC.
       the GS's `AFAIL` bit reads as "fail if above the reference" and on the
       hardware means the opposite -- it discards where alpha is **below**; and the
       opaque bit must be kept out of the comparison, or `0x80` satisfies every
-      threshold and nothing is ever discarded. **No wgpu work has started** --
-      this is the rule layer the renderer will feed it, done first because it is
-      checkable without a GPU.
+      threshold and nothing is ever discarded. **The engine is on bevy 0.19, not raw wgpu**, so these rules reach the GPU
+      through bevy's sampler rather than wgpu directly. One is now wired: the
+      texture sampler was `..default()` with a comment claiming it clamped, and
+      bevy's default is `Repeat` -- see `image_of` in `crates/gc-engine`.
+      **No draw-path or shader work has started.**
 - [ ] VU0/VU1 skinning and lighting on the PS2 float model
 - [ ] LOD/morph/cull per `TfragProc` and `TieProc`
 - [ ] Occlusion culling, fog, shadows