Hi Lorem

I have found that the Network tool can be quite temperamental.
You have to use trial and error sometimes to get a surface just right.
I have been fiddling with an Audi TT car for a couple of month's (almost done) and have had the same sort of problems as you have encountered. Tried hundreds of ways to do the front wing but eventually cracked it with trial and error.

I have had a go with your chair and I think this is what you are after.

Notice the outer shell is just a mirror of the original - but still keeping the split down the middle, that is importatant for it to work - and then I used the back spline to creat the curves, just touching, to get the right shape.

Keep on trying and you will succeed I am sure.

Best of luck.
Malc.

Hi Lorem,

> Here is another 3dm scene....I tweaked curves in order to have a
> perfectly mirroring object..and now network tool have no result....

It looks like MoI is getting confused about how to organize the curves.

If you turn on control points for your small curves and drag their endpoints so that they are snapped right on to the longer ones, that will clear up the organization and Network will then succeed.

If you run into other problems with Network, try to align the ends of your curves more precisely snapped on to each other and that should help. I will see if I can tune this up so that it isn't necessary though.

You can also use sweep for situations like this with 2 longer guide curves - it can be less fussy about how things are arranged.



One other issue - even though you have tweaked your curve tangents you will still not have a perfectly mirroring object here. It will be perfectly mirroring right at those curves, but in other areas the cross-section will shift and torque around which gets in the way of perfect alignment. For example here is what the control points look like near the tip of the surface:



That shifting happens because Network is not only created off of those profile curves but also the other long curves as well, which do not have equal length and pinch together at the top.

For network it can be easiest to get a smooth object by doing the full object all at once instead of half.

There is a special "Maintain tangent" mode for sweep which can build a smooth mirrorable object, but right now it only works if all your profile curves are on parallel planes. It works by keeping all the control points along those same planes instead of shifting them along the rails which is what normally happens. I think I should be able to tune up this sweep mode in the future to handle situations like the one you posted here.

- Michael

One other tip - if you plan on thickening this shape up later, it may be better results doing that if your basic surface does not pinch together at the top and bottom - shelling and offseting surfaces tends to be sensitive to tips like this that collapse down to a single point.

If you want to make shelling work sometimes right now you will have to create a more rectangular base surface that is not pinched at the ends, and then trim it to make your curved outline.

That kind of non-pinched-at-the-tip underlying surface with a trimmed outline will tend to shell a lot more reliably.

- Michael

Thanks again for your helpfull answers...

Malc615 --> you have exactly what I was looking for. So, the only thing I had to do with my first attempt was to divide the main shape in 2, and use network tool.
So cool ! I can go on with the other parts

Michael :
"You can also use sweep for situations like this with 2 longer guide curves"
Yep,I tried it, it also works but I have less control on the volume...but it's usefull.

"For network it can be easiest to get a smooth object by doing the full object all at once instead of half."
That's what I was trying to do at the beginning, but it didn't work. Now, with the Malc615's advises it's OK.


(sorry if my english is not so good)

Post soon, when done !