very thanks!
i find i make a very stupid mistakes~
help,it says after splited must redefine the hull...so i just select the splited hull..ha ha

thanks u again!  i will check the results with the towing tank experiment's value~

thanks for lleibman  help,
i know that is a self-experiential method,but
what i confused is that when we set the value for the Weight,VCG,LCG,
can select "From Design Condition",but just use the hull(splitd from chine)

the help say:
Note: the weight, LCG, and VCG can be automatically filled in by Orca3D
if a design condition is specified after the planing surface is split (if necessary) from the hull surface by clicking the From Design Condition box.

so it just use splited hull not the original ship hull ,
that weight and VCG LCG values all caculated from splited hull~
don't need to use real ship hull that makes me confused~

ex: 
that's what i do in my model

defind the design condition(float plane 1.28 select all surface but deck)

original
(this by speed & power)
weight:56192.53 kgf
LCG           13.976m  (but from _AreaCentroid is 12.79 why not be equal??)
VCG              1.72m  (from _AreaCentroid)

calculate _AreaCentroid from all surface(transom & hull but no deck and mirror them)
so the LCG VCG can be know~

after split
defind the design condition again (float plane 1.28 select all surface but deck)

weight :44480.61kgf
LCG :    12.95 m   (but from _AreaCentroid is 12.64)
VCG      0.75  m    (from _AreaCentroid)

also calculate  _AreaCentroid(splited transom surface ,splited hull surface and mirror them)

thanks for help so much~

sorry does somebody know the Orca3D can be use in calculate the speed & power which the hull has tunnel?
the propeller will be inside the hull(side view)

and i feel confuse that when we calculate the hull , we just select the surface below the chine , the planning surface ,
can use that to cal. the disp. LCG VCG....etc.
now these all  about the splited  planning surface but not the total hull surface,
 i feel confuse that won't be affected to the result?

stupid problem~ thanks!


Btw,the Orca3D's annotation(for recording the  ship assistant's parameters)
have some bug ,the item "sheer Heigh" will automatic add "ft"(or another length unit) behind the word, but actually this is scale

and the tree layer manager sometimes the icon have some wrong