Instanced geometry (e.g. a game world's block grid rendered via DrawInstanced) MUST cast shadows. Unlike ShadowMeshDraw this carries many per-instance world transforms; the pass renders it via the depth effect's DepthInstanced technique with a two-stream vertex bind (mesh + per-instance VertexInstanceWorld), one DrawInstancedPrimitives per light. No per-instance frustum cull — the sample already chunk-culls the source commands, so the emitted count is small; the cost is bounded by the surviving instance counts.