PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment is a light-to-medium weight matte fabric, likely a cotton-modal or viscose blend. It exhibits low specular reflection (non-shiny) but possesses a fluid drape. Unlike the user's current rigid ribbed knit, the source fabric is flowy and prone to soft, vertical folding rather than clinging to body contours. - **Key Features:** The wide boat-neck/crew-neck collar with visible top-stitching must be preserved. The boxy, sleeveless silhouette (cap-sleeve effect) is critical. The hemline appears slightly curved and relaxed; this geometry must replace the straight, tight tuck of the current user's top. The beige/tan hue must remain consistent, avoiding washout in the bright sunlight. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** The current user is wearing a form-fitting long-sleeve top, whereas the source is a loose, relaxed fit. The simulation must generate a "bridge" over the waist indentation; the new garment should hang vertically from the bust line and shoulders due to gravity, rather than hugging the torso. Because the source is sleeveless and the target is long-sleeved, skin texture generation is required for the user's arms, maintaining the lighting and skin tone consistent with her face. - **Occlusion Handling:** The user's long dark hair falls significantly over her left shoulder and upper chest. This is a critical occlusion layer; the beige top must be rendered *underneath* these hair strands. The hair strands must not be blurred or cut off. The barrier railing in the foreground intersects the lower torso area and must remain the top-most layer, occluding the bottom hem of the new shirt. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The user is in a high-altitude outdoor environment with harsh, direct sunlight coming from the upper-right (creating strong, hard shadows). The source garment (currently studio-lit) must be re-lit to cast hard self-shadows, particularly under the bust and inside vertical folds. The beige fabric must interact with the blue skylight fill in the shadowed areas to match the ambient environment. - **Color Calibration:** The source beige is neutral. In the target image, the sunlight is intense and warm. The garment's texture must reflect this high exposure without blowing out to pure white. The contrast needs to be increased to match the sharp dynamic range of the mountain background. PHASE 4: IDENTITY PROTECTION - **Facial Lock:** The user's entire head region, including the red knit headband, facial expression, skin tone, and hair volume, must remain pixel-perfectly frozen. - **Body Integrity:** The user's underlying skeletal structure and pose (leaning back against the barrier) must remain unchanged. While the *silhouette* of the torso will widen slightly due to the looser fit of the new shirt, the user's actual anatomical proportions (shoulder width, arm thickness) must not be slimmed or warped.