PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment appears to be a black cotton poplin or fine twill. It has a high structural rigidity, particularly in the collar and cuffs, meaning it will not cling like the user's current jersey knit tank top. The material has a matte finish but will exhibit specular highlights on the shoulder ridges and fold crests due to the tight weave. - **Key Features:** The sharp, structured point collar must be preserved and properly seated around the user's neck. The vertical button placket must remain centered. The distinct cuff construction at the wrists is essential, replacing the user's currently bare arms. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** The user has a muscular build with developed deltoids and biceps. The source shirt (slim fit) must expand at the shoulders and chest to accommodate the user's broader frame without stretching the texture unnaturally. Unlike the current tank top, the new garment must generate full sleeves on the user's bare arms; these sleeves should drape relatively straight with slight stacking/bunching at the wrists and subtle tension creases radiating from the armpit to the shoulder. - **Occlusion Handling:** The silver pendant necklace currently sits on the user's chest. This object must be segmented and layered *over* the new black shirt (assuming the shirt is rendered partially unbuttoned to allow this) or logically hidden if the shirt is fully buttoned. The user's beard slightly overlaps the neck area and must overlay the new shirt collar. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The user's environment features a complex mixed-lighting scenario: a cooler, harder key light coming from the front-left and strong warm (red/orange) ambient light from the background bokeh. The black shirt must absorb the frontal light but generate distinct, slightly cool highlights on the folds to define shape. Crucially, the shoulders and edges of the sleeves must reflect the red/orange environmental rim lighting to integrate with the background. - **Color Calibration:** The source black is a studio "absolute black." This must be lifted and adjusted to match the black point of the user's photo, incorporating the high ISO noise/grain visible in the target image to preventing the shirt from looking too smooth or synthetic. PHASE 4: IDENTITY PROTECTION - **Facial Lock:** The user's entire head, including the specific grooming of the beard, the hairstyle, and the ears, must be frozen. The jawline definition must remain unaltered where it meets the new collar. - **Body Integrity:** The user's muscular volume (shoulder width and arm thickness) must be preserved. The simulation must fit the shirt to the user, not shrink the user to fit the model's slimmer silhouette.