人像交叉影线网格效果

Add a bold, coarse dark gray crosshatch grid over the face, using thick, evenly spaced straight diagonal lines to form large diamond-shaped cells. Render it as a flat 2D graphic overlay with no curvature, warping, or perspective distortion. Clip the grid to a simple vertical oval covering only the face, excluding the hair, ears, neck, and clothing; do not draw the oval outline. Preserve the original person, facial features, expression, lighting, and composition exactly.