【讨论】 Use of History Tree

Hi 大家好：
  
我已经用IDEAS 两个星期了。以经能画一些简单的 part 了。 但是还未能掌握他的窍妙之处。
现在想问一下关于 History Tree 的用法。 在我的公司的人画的时候总是现画几个小part,在用 Bollean operation 例如 join, Cut, Intersect 将小part 合起来。他们为什么不用 Sketch On Plane 呢？那不是更快吗？ 他们说如此作以后会更加容易 Modify.
  
可以讲解一下 IDEAS 在作大part 和 assembly 的 Tips & Trick 吗？需要注要那些事项吗？ 我公司是做电视机的，一个part 大概有几百个Feature. 用的是IDEAS 8.0.  
  
再问一下Reference curve 的用法吗？我真的有点胡图了。以下是我在comp.CAD.ideas 得到的答复，和大家分享。
  
谢谢。
  
IanR wrotes :
  
The sketch on plane modelling method, producing a linear history tree was
the preference for earlier Master Series Releases. It is possibly are
quicker way to model if you're always moving forward, never returning to
features already created to modify or re-order them.
  
There were also some issues with the software in earlier releases, with it's
handling of migrating geometry. If there was a "Branch" of  history tree
that needed to be removed but contained reference geometry then the features
could be deleted but the reference geometry would "migrate" to the next
lower node in the main stem. Once migrated, and with all relations removed,
they would then corrupt and be un-deleteable.
  
With these earlier issues fixed and the "real world" scenario being that the
part history is constantly replayed, edited and re-ordered, the Boolean
modelling method, producing a "bushy" tree became favoured (in general).
  
Although perhaps taking slightly longer to initially create geometry,
editing an area is much quicker since returning to an operation halfway down
the tree doesn't require all the lower operations to be replayed, just the
operations with it's branch.
  
With regards to reference features, these can be treated as the backbone of
the part. Properly constructed they allow the design intent of the component
to be captured and easily modified. It is often preferred to create
reference geometry for a new feature rather than sketching on an already
existing face, to avoid editing issues later if that face moves, or becomes
"out-of-date".
  
How best to use them is a big subject, you need to break the question down
to avoid an even longer answer.

布尔运算在i-deas里的确是一大优势，它的历史树往往成一棵树状有许多分叉，与proe，sw不太一样。灵活性更强，更便于修改。
总是感觉i-deas太深奥，再加上参考资料太少，很难琢磨透
（ccf兄，可以把这段文字翻译成中文吗？俺是英盲……呵呵）

i-deas的历史树确实好管理，又直观。::y::y::y

Diego,
  
I am very slow typing chinese. It i time you learn English, good to your future.