PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment is structured denim (likely cotton twill). It possesses high bending stiffness and shear resistance; it will not conform tightly to body curvature like jersey or silk. Lighting interaction must show anisotropic reflection characteristic of denim weave, with matte diffusion on the blue dye and sharp specular highlights on the metal buttons. - **Key Features:** The vertical "princess seam" topstitching (yellow thread) is critical for structural definition and must be preserved. The five antique-brass style shank buttons, the two lower patch pockets, and the characteristic W-shaped pointed hemline at the waist are non-negotiable geometry. The retail tag and hanging thread loop must be digitally excised. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** As a sleeveless vest/waistcoat, the simulation must generate accurate skin texture for the user's arms (currently covered by long sleeves) matching the facial skin tone. The vest must sit flush against the shoulders but bridge the gap at the waist due to denim's rigidity, rather than clinging to the midriff. The V-neckline should align with the user's clavicle structure. - **Occlusion Handling:** **Critical:** The user has long, dark hair falling over both shoulders and down the chest. A high-precision alpha mask is required to layer the hair strands *over* the denim vest. The user's hands are positioned at the hip/pocket level; the vest's pointed hemline will likely terminate just above or at the wrist line, requiring careful depth compositing to ensure the hands remain in the foreground if they overlap the vest's bottom edge. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The user's environment has cool, diffuse indoor overhead lighting (LED approx 5000K), casting soft shadows downward under the chin. The source cloth image has warmer, directional lighting. The render engine must neutralize the yellow cast from the source image and apply the cool ambient occlusion of the target room to the denim. - **Color Calibration:** The denim's indigo hue must be color-corrected to appear natural in the user's lower-contrast environment. Shadows generated by the vest (particularly inside the armholes and under the buttons) must match the density and softness of the shadow currently seen on the user's neck. PHASE 4: IDENTITY PROTECTION - **Facial Lock:** Absolute pixel preservation required for the user's face, neck, and distinct hairstyle. The facial structure, makeup, and expression must remain frozen. - **Body Integrity:** Zero-tolerance for warping or "slimming" algorithms. The user's shoulder width and hip placement must remain distinct. The volume of the torso should reflect the added thickness of the denim material, not shrink the user's silhouette.