jiāng / wù tǐ / yǔ / tóu yǐng zhōng xīn / lián xiàn / kě yǐ / dé dào / tā / zài / píng miàn / shàng / de / tóu yǐng将物体与投影中心连线,可以得到它在平面上的投影。By connecting the object with the center of projection, you can obtain its projection on the plane.