asterism

Tourmaline is one of the most important semiprecious stones in the world, with particular cutting features such as undeveloped cleavage and high tenacity, rich in color, strong pleochroism, special optical effect of asterism and cat' eye.

碧玺是宝石世界中最重要的中档宝石，具有独特的加工性质，如解理不发育、韧性强、颜色丰富多彩、多色性强、具有星光和猫眼特殊光学效应等。

( of some crystals especially gemstones) exhibiting asterism.

（属于一些水晶特别是经雕琢过的宝石）显示星彩。

Based on these models, physical principles behind imaging effects of defocused blur, motion blur and asterism were analyzed thoroughly, and methods to simulate these effects were proposed as well.

基于这些模型，深入分析了星空环境下成像过程中背景离焦模糊，运动模糊和星芒这三种效果的形成原因并提出了针对性的模拟方法。