diff --git a/docs/manual/editor/lighting.md b/docs/manual/editor/lighting.md
index 29331c2..f961b31 100644
--- a/docs/manual/editor/lighting.md
+++ b/docs/manual/editor/lighting.md
@@ -64,11 +64,14 @@ tiles or draw budget still illuminates, **without a shadow**. Disabling
 The renderer reports requested faces, rendered faces, tiles, and drops by cause
 in [Diagnostics](diagnostics.md) and the [Player profile](profiling.md).
 
-Faset uses separate sampled D32 sun and local atlases, normally 2048×2048 pixels
-each. If a device cannot use that size, the renderer tries 1024×1024; if a
-sampled depth atlas cannot be created, the affected lights fall back to unshadowed
-illumination and report unavailable shadow views. Scheduled atlas tiles are
-cleared and redrawn each frame; there is no persistent shadow cache yet.
+Faset requires sampled D32 depth images for the renderer itself. On a supported
+device, it uses separate sun and local atlases, normally 2048×2048 pixels each.
+If an optional atlas cannot use that size, the renderer tries 1024×1024. When
+the local atlas cannot be allocated, or the sun atlas cannot be allocated but
+a 1×1 sampled D32 fallback image can, affected lights remain unshadowed and
+report unavailable shadow views. A device without sampled D32 support cannot
+start this renderer. Scheduled atlas tiles are cleared and redrawn each frame;
+there is no persistent shadow cache yet.
 Sprite-only scenes, a missing sun, and a sun with `casts_shadow: false` skip sun
 shadow raster work.
 
diff --git a/docs/validation/p3-lighting-2026-09-24/README.md b/docs/validation/p3-lighting-2026-09-24/README.md
index 26940ae..29bc6e6 100644
--- a/docs/validation/p3-lighting-2026-09-24/README.md
+++ b/docs/validation/p3-lighting-2026-09-24/README.md
@@ -45,7 +45,7 @@ the new tiled revision is pending. Temporal reconstruction has its own acceptanc
 | Empty, disabled, local-only, multiple sun; schema bounds | `scene_view`, `render_lighting_policy`, `render_offscreen` | Linux Debug green at `a0a4e29`; integrated revision pending |
 | Four cascades, split bounds, subtexel stabilization, offscreen/source-LOD0 caster | `render_lighting_policy`, `render_lighting_sun` | Linux GPU and pinned SwiftShader P3 green at `a0a4e29` |
 | Spot cone, six point faces and seam, dropped whole point shadow | `render_lighting_local`, `render_lighting_policy` | Linux GPU and pinned SwiftShader P3 green at `a0a4e29` |
-| 128-light/16-face/4096-draw limits, unsupported-atlas fallback | `render_lighting_policy`, `render_offscreen`, `render_lighting_local` | CPU and supported-atlas GPU paths covered; actual unsupported Vulkan device not tested |
+| 128-light/16-face/4096-draw limits, optional-atlas fallback | `render_lighting_policy`, `render_offscreen`, `render_lighting_local` | CPU and supported-atlas GPU paths covered; allocation fallback not exercised on an actual constrained device; sampled D32 is a renderer requirement |
 | Direct/GPU frustum/GPU occlusion image parity, P2 reload and 2D/UI independence | `render_lighting_sun`, `render_lighting_local`, `render_shader_reload`, `render_offscreen` | Linux Debug green at `a0a4e29`; integrated revision pending |
 | Forward+/forward parity, near plane, resize, overflow, and shader reload | `render_lighting_tiled`, `render_shader_reload`, `render_shader_reflection`, `build_schema_publication` | Linux Debug and pinned SwiftShader P3 green at `a0a4e29`; 128-light localized Release captures match exactly |
 | Driver, profile, real 64×64 benchmark smoke | `render_lighting_benchmark_schema`, `render_lighting_benchmark_smoke`, `player_shutdown_diagnostics` | Full Linux Debug green at `a0a4e29` |