PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment is a melange grey cotton jersey or cotton-poly blend. It possesses a "matte" surface property with high light absorption and low specularity. The simulation must reflect a soft, pliable drape with moderate elasticity (stretch) typical of knit undergarments. - **Key Features:** The distinct ribbed binding (piping) around the neckline and armholes is a critical structural detail that must be preserved. The marled/heathered texture of the grey fabric needs to be retained to avoid a flat "computer-generated" look. The neckline is a deep scoop, differing significantly from the user's current high-collared shirt. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** * **Sleeve Transformation:** This is a complex transformation requiring the removal of the user's existing long brown sleeves. The system must generate realistic skin texture and arm anatomy for the target's bare arms and shoulders to match the sleeveless cut of the source tank top. * **Torso Fit:** The tank top should follow the user's slight torso rotation to her right. The fabric must drape naturally over the bust without the rigid structure of the current collared shirt. * **Hemline Interaction:** The user's hands are interacting with the waistband/hips. The tank top's hem needs to settle naturally around the hip line; if the tank is long, it should simulate being tucked or bunching slightly where the hands press against the jeans. - **Occlusion Handling:** * **Hair:** The user has significant hair volume falling over her right shoulder (viewer's left) and behind the left shoulder. This hair MUST be segmented and layered *over* the new grey tank top strap. * **Hands/Waist:** The user's thumbs and fingers at the pocket line must layer *over* the garment if the garment length extends that low. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The user image features soft, diffuse, high-key lighting, seemingly originating from a large window on the viewer's left. Shadows on the new garment must be soft and graduate toward the right side of the torso. - **Color Calibration:** The source image has a cooler, studio-lit tone. The grey of the tank top must be color-graded to match the slightly warmer, natural indoor ambient light of the user's environment. Ambient occlusion shadows must be generated under the hair and under the chin to ground the garment. PHASE 4: IDENTITY PROTECTION - **Facial Lock:** The user's entire head, including the jawline, facial expression, and the specific fall of the hair around the face, must remain pixel-perfectly frozen. - **Body Integrity:** The simulation is strictly forbidden from altering the user's waist width or shoulder breadth. While the arms must be generated (due to the sleeve removal), the volume of the torso and the user's posture must remain authentic to the original image.