当权重为正值时，会加重边缘的描绘；当权重为负值时，会减弱边缘的描绘。
When the weight is positive, it adds to the depiction of the line; when the weight is negative, it weakens the depiction of the line.
当权重为正值时，会加重边缘的描绘；当权重为负值时，会减弱边缘的描绘。
When the weight is positive, it adds to the depiction of the line; when the weight is negative, it weakens the depiction of the line.