PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment is a heavy cotton twill or canvas utility jacket. It possesses high structural rigidity and low drape (stiff). It has a matte finish that absorbs light, unlike the user's current slight sheen top. The simulation must treat this as a semi-rigid shell rather than a flowy mesh. - **Key Features:** - Two large, dimensional chest pockets with flaps (must retain 3D volume, not look flat). - Silver snap buttons and metal zipper teeth (must maintain high specular reflectivity). - Drawstrings at the cropped hemline (must obey gravity). - Adjustable buckle straps at the sleeve cuffs. - Standing/structured collar. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** - **Shoulders/Chest:** The jacket is boxy/oversized. It should fit the user's shoulders snugly but drape vertically over the bust without contouring tightly to the waist. - **Sleeves:** Since the user's arms are bent at an acute angle at the elbow, the stiff canvas fabric must generate heavy, sharp transverse folds (honeycombing) at the inner elbow. The sleeves will extend to the wrist. - **Hemline:** As a cropped jacket, the hem should land approximately at the user's natural waist, hovering just above the waistband of the black trousers. - **Occlusion Handling:** - **Hands:** The user's hands are clasped at the mid-section. The jacket sleeves will likely terminate at the wrists; the user's hands must be segmented and layered *over* the jacket cuffs and bottom hem. - **Neck:** The user's neck is visible; the jacket collar must wrap behind the neck, replacing the current collared shirt, without clipping into the jawline. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The user is in an environment with a strong, cool-toned light source coming from the front-right (casting shadows to the left on the curtains). The jacket's shading must generate a drop shadow onto the black trousers and a cast shadow against the grey curtains to the left. - **Color Calibration:** The source jacket is lit by bright, diffuse outdoor light. The target environment is dimmer with artificial indoor lighting. The olive green must be slightly desaturated and the exposure lowered to match the user's room tone. The silver buttons must reflect the specific "ring light" or window source present in the user's room. PHASE 4: IDENTITY PROTECTION - **Facial Lock:** Absolute freeze on the user's face, hair, and ears. The neck area above the clavicle must remain untouched. - **Body Integrity:** Strict prohibition on body reshaping. The jacket must be warped to fit the user's existing skeletal structure and volume. Do not slim the user's arms or torso to match the source model's proportions; the garment must expand to accommodate the target user.