Surface and volume calculation

[nayanakantha843]

I attach picture 1 and 2. please see it 

i need crate surface like this pictuire 2.

i need crate surface by joining 1, 2, 3 like as picture 2 section

but when i crating surface its joining as picture.

this problem have been found 

i crated a tofo of the rock which rock is bend lower picture 2 section 

to calculate the volume i need the surfce crate like this.

please anyone can replay for slove this dout or another method for calculate volume 

[JSpell · Accepted solution]

You won't be able to have a single surface with multiple z values.  Triangulation shape is horizontal only, so this doesn't allow for a single over lapping surface.  I would stick with multiple surfaces and try to make that work.

[neilyj666 · Accepted solution]

You may find some guidance here http://docs.autodesk.com/CIV3D/2013/ENU/index.html?url=filesCUG/GUID-B75FEF9F-1020-4E66-B1B4-196732B... but you will need to split the surface you have into two; upper and lower