PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment is a structured matte cotton or linen blend with a boxy silhouette. It has low specular reflectivity (matte finish) and should not shine under the strong backlight. The fabric weight is medium—heavier than the user's current jersey t-shirt—meaning it will form larger, stiffer folds rather than small micro-creases. - **Key Features:** The high-contrast white floral embroidery running vertically down both front panels must remain crisp and undistorted. The "Cuban collar" (open notch lapel) structure is critical and replaces the current crew neck. Distinctive white stitching on the sleeve cuffs, hemline, and button placket, along with the black buttons, must be preserved as geometric anchors. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** The source shirt is a "Relaxed Fit" button-down, whereas the user is wearing a fitted t-shirt. The simulation must expand the silhouette slightly away from the torso to mimic the looser cut. On the user's left side (viewer's left), where the arm extends to the railing, the fabric must pull tight across the deltoid and lift the sleeve hem slightly. On the right side, the sleeve should hang naturally vertical due to gravity. The hemline should fall straight, likely untucked, sitting slightly lower and looser than the current t-shirt. - **Occlusion Handling:** The user's left hand (resting on the railing) is below the sleeve line, so no hand occlusion on the garment itself. However, the black wristband on the right arm (viewer's right) must be checked against the new sleeve length; if the sleeve is longer than the t-shirt, it may cover the band. The railing is behind the user, so no environmental occlusion blocks the torso. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The user image features strong, warm backlighting (sunset) creating a "rim light" effect, with the front of the torso in shadow. The new black shirt must accept this lighting model: deep, noisy shadows on the front torso, with a bright, warm halo/rim light along the shoulders and arm edges. - **Color Calibration:** The stark white embroidery and stitching on the source shirt must be color-graded to a warmer, creamy off-white to match the golden hour ambient light. The deep black fabric must be lifted slightly to a dark charcoal/brown-black in the shadowed areas to match the dynamic range of the user photo, preventing a "black hole" effect. PHASE 4: IDENTITY PROTECTION - **Facial Lock:** The entire head, including the jawline, hair, and sunglasses, must be strictly frozen. The neck area above the suprasternal notch needs masking to seamlessly blend the new open-collar skin tone with the existing neck. - **Body Integrity:** The user's shoulder width and torso volume must remain constant. Do not warp the user's torso to match the slimmer mannequin from the source image. The simulation must drape the cloth *over* the user's existing volume, not shrink the user to fit the cloth.