Change only the region or part I specify or mark; everything else stays exactly as in the input (composition, perspective, lighting, colour and sharpness). Scope: only my specified or marked region; anything unmarked must not be altered, repainted, relit or re-materialised. Marking wins: if the input includes an annotated, masked or painted region, operate strictly inside it. Blending: the edit must match its surroundings in material, texture and light direction, with no hard seams, colour patches, outlines or brightness jumps. Output one single finished image only, with no comparison view, boxes, arrows or explanatory text.
