def normalize_obj_custom(old_file, new_file):
    vertices = []
    other_lines = []

    # Step 1: Read the OBJ file and extract vertices
    with open(old_file, 'r') as file:
        for line in file:
            if line.startswith('v '):  # Vertex line
                parts = line.split()
                vertices.append([float(parts[1]), float(parts[2]), float(parts[3])])
            else:
                other_lines.append(line)  # Non-vertex lines

    # Step 2: Find the min and max for each axis
    min_x = min(vertex[0] for vertex in vertices)
    max_x = max(vertex[0] for vertex in vertices)
    min_y = min(vertex[1] for vertex in vertices)
    max_y = max(vertex[1] for vertex in vertices)
    min_z = min(vertex[2] for vertex in vertices)
    max_z = max(vertex[2] for vertex in vertices)

    # Step 3: Normalize x, y to [-1, 1] and z to [0, 2]
    normalized_vertices = [
        [
            2 * ((vertex[0] - min_x) / (max_x - min_x)) - 1,  # x to [-1, 1]
            2 * ((vertex[1] - min_y) / (max_y - min_y)) - 1,  # y to [-1, 1]
            2 * ((vertex[2] - min_z) / (max_z - min_z))       # z to [0, 2]
        ]
        for vertex in vertices
    ]

    # Step 4: Write to the new OBJ file
    with open(new_file, 'w') as file:
        # Write normalized vertices
        for vertex in normalized_vertices:
            file.write(f"v {vertex[0]} {vertex[1]} {vertex[2]}\n")
        # Write other lines (e.g., faces, normals, etc.)
        file.writelines(other_lines)

# Example usage:
normalize_obj_custom('textured.obj', 'new.obj')