PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment is a standard cotton jersey knit (matte finish). It possesses low specular reflection (no shine) and high flexibility. The simulation must render it as soft and pliable, absorbing the scene's ambient light rather than reflecting it like synthetic sportswear. - **Key Features:** The central "One Piece" anime character collage graphic is the primary anchor; it must be centered on the sternum. The crew neckline (ribbed collar) must replace the current polo collar. The red brand tag at the bottom hem should be preserved only if the shirt is worn untucked; otherwise, it is ignored. The base color is beige/light sand. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** The current polo shirt has a structured collar; the new T-shirt is unstructured. The simulation must synthesize the skin of the lower neck/trapezius area where the polo collar currently hides the body. Gravity will cause vertical draping from the acromion (shoulder tip) down. The fit should be "Regular," meaning it skims the pectorals but hangs somewhat loose around the midsection, unlike the slightly fitted polo. - **Occlusion Handling:** The user's beard is the primary occlusion point; the new crew neck collar must sit *under* the beard line, and any beard hair overlapping the current collar must be segmented and layered over the new beige fabric. The arms are clear of the torso, simplifying the side-seam generation. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The user's environment has strong, warm overhead lighting (likely a ceiling fixture), casting downward shadows (notice the shadow under the nose and chin). The new garment must generate self-shadows (ambient occlusion) in the folds that align with this top-down direction. - **Color Calibration:** The source cloth is photographed in neutral/cool light. In the target scene, the beige fabric must absorb the warm (yellow/orange) temperature of the room's lighting. The graphic's colors must be slightly desaturated and warmed to match the contrast levels of the user's skin tone in this specific lighting condition. PHASE 4: IDENTITY PROTECTION - **Facial Lock:** Absolute freeze on the facial structure, specifically the jawline, beard density, and the sunglasses. The sunglasses must remain untouched. The hairline and ears are excluded from the generation mask. - **Body Integrity:** The user's shoulder width (deltoid to deltoid) and arm circumference (bicep/tricep) must remain exact. The simulation is strictly forbidden from slimming the torso or adding artificial musculature; the silhouette of the body underneath the fabric must match the input image.