PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment is a ribbed knit fabric (likely cotton-elastane blend). It exhibits anisotropic reflection—matte but with high contrast between the peaks and valleys of the vertical ribs. The physics engine must treat this as a high-elasticity material that contours closely to the body (bodycon fit) rather than hanging loosely. - **Key Features:** The vertical ribbing texture is the primary visual signature and must remain continuous around body curvature. The wide boat-neck (bateau) neckline is structurally distinct from the user's current collared polo and must replace the neckline geometry completely. Long sleeves with finished cuffs must be generated where bare skin currently exists. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** Due to the seated posture, the fabric simulation must calculate compression folds (transverse buckling) across the abdomen and lower waist area. The long sleeves must drape naturally over the user's arms; specifically, the fabric must bunch on the inner elbow (ante-cubital fossa) and stretch taut over the outer elbow (olecranon) due to the slight arm bend. - **Occlusion Handling:** The user's hands are clasped and resting on the lap/thighs. This is a critical occlusion zone. The lower hem of the new garment will likely terminate near the wrist/hand area. The hands and fingers must be strictly segmented and layered *over* the new fabric. The waistband of the trousers is currently visible; the new top should drape slightly over the waistband, interacting with the thigh crease. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The target environment features diffuse, overhead artificial lighting, casting soft shadows downwards and slightly to the user's right (viewer's left). The new white garment will reflect significantly more light than the original dark navy top. Self-shadowing (ambient occlusion) must be aggressively applied within the ribbing grooves to prevent the white shirt from looking "flat" or overexposed. - **Color Calibration:** The target room has a warm/yellowish color temperature. The sterile white of the source cloth must be color-graded with a subtle warm cream tint to match the ambient scene lighting, ensuring it integrates with the skin tone and background cabinetry. PHASE 4: IDENTITY PROTECTION - **Facial Lock:** The user's entire head, including the hairline, ears, neck shape, and facial expression, must be frozen and masked. No skin tone alteration is permitted on the face or neck. - **Body Integrity:** The generation must replace the bare forearms with cloth but MUST NOT alter the volumetric dimensions of the user's arms or torso. No slimming, lengthening, or reshaping of the user's silhouette is permitted; the garment must adapt to the body, not the body to the garment.