暗部的纹理完全看不清，同样在一些亮部区域纹理也不显著，比如前额和左侧边缘。

It's also not terribly prominent in the fully lit areas of lighter halftone, such as the forehead and the left hand edge of the form.

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注意中央光和高光的位置是不一样的。明暗交界线是物体从亮部转入暗部的区域。这个就是光线和表面相切。

To test which areas are in light and which are in shadow, you can cast a shadow with a pencil on the object.

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