PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment is a lightweight, jersey-knit cotton blend. It exhibits a matte finish with low specular highlights. The drape is soft and pliable, prone to micro-folds around movement points (elbows, waist) rather than structural rigidity. It behaves like a standard mid-weight tee, obeying gravity immediately without stiffness. - **Key Features:** - **Long Sleeves:** Crucial structural change from the user's current short sleeves; must extend to wrists. - **Crew Neckline:** Ribbed collar detail must be preserved. - **Chest Logo:** Small, minimal avian logo on the upper left chest must be mapped correctly to the pectoral region. - **Hemlines:** Standard straight hem at the waist and sleeves, no distressing. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** - **Torso Definition:** The source garment is a "Regular Fit," whereas the user is currently wearing an "Oversized/Boxy Fit." The simulation must ignore the volumetric outline of the current blue shirt and map the green shirt closer to the user's actual anatomical torso. - **Left Arm (Raised):** Physics simulation is critical here. Fabric must bunch significantly at the left shoulder/deltoid and armpit area. The sleeve should slide slightly down the forearm due to gravity, potentially exposing the wrist bone. - **Right Arm (Relaxed):** The sleeve should hang vertically with minimal tension, creating vertical drape lines (columnar folds) from shoulder to wrist. - **Occlusion Handling:** - **Silver Necklace:** The chain is currently resting *on top* of the collarbone area. This object must be segmented and layered *over* the new green crew neck. - **Left Hand/Forearm:** The user's left hand is touching the hat; the new long sleeve will cover the forearm tattoo, meaning the tattoo is an occluded element that must be hidden by the new fabric. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The user image utilizes soft, diffuse studio lighting, predominantly from the upper-left quadrant (indicated by the shadow on the right side of the neck). The new garment must generate self-shadowing in the armpits and torso folds consistent with this top-left light source. - **Color Calibration:** The source garment is a pale sage/mint green. The user environment is cool-toned (bluish tint). The green garment requires slight color grading to match the white balance of the target scene, ensuring it doesn't look "pasted on" or too warm/yellow for the cool studio setting. PHASE 4: IDENTITY PROTECTION - **Facial Lock:** Absolute freeze on the user's face, neck structure, and the white cap. The jawline shadow must be preserved and re-cast onto the new collar if the neck height changes. - **Body Integrity:** Do not slim the user's actual physique. While the source shirt is tighter than the target shirt, the underlying body mass (shoulders, chest width) must remain constant. Do not warp the jeans or the hand positioning.