Hi,
I was looking at Tspline and they look really interersting. The way you modifiy your shape on the fly is great.
I was wondering how you could achieve the same result in Moi or something similar.
At the moment from what I watch the best way to modify your shape is to use the lofting technique presented by Samardac.
I found this technique cool but it need a big amount of work, you really have to plane your curves correctly.

One thing I was thinking that could help to modify your shape on the fly is being able to change a shape done with revolve rail.
But if you move one outline curve you have to tweak it to make it work with your rails curves.

So I was thinking, could you have a tool similar to slide edge in polymodeling where you take a curve and your railing curves and then move the curve you want to modify and it will follow the railing curve adjusting on the fly.
That could speed the process of having to rescale and reshape your curves and having something more interactive :D

Hi David,

> I was looking at Tspline and they look really interersting. The way you modifiy
> your shape on the fly is great.
> I was wondering how you could achieve the same result in Moi or something similar.

Well Tsplines actually is basically a sub-d modeling toolset. The main difference is that they can do a conversion from sub-d surfaces into regular CAD NURBS surfaces at the end.

You can get the same kind of modeling tools in Tsplines in other sub-d modeling programs currently - basically if you want to work in a similar manner to tsplines you would want to do that work in a sub-d modeling program and not in MoI.

MoI is based on a very different kind of toolset than sub-d modeling, it's based on profile curve driven modeling.

It's not really feasible to try and do sub-d type modeling in MoI currently, the entire workflow and featureset and orientation of the entire system is just not set up for that. There are many other programs that already offer sub-d modeling, which is partly why MoI is focused on different things that that.


As far as sliding a curve, I'm not 100% sure if I understand what you want to do, but it is possible to extract structural curves from an existing surface using the Construct > Curve > Iso command (new in v3) which allows you to extract out lines of the underlying UV space 2D grid as independent curves. If you do it on a revolve it will extract out sections of the revolve basically.

- Michael

I thought he was asking for this type of thing...



But isocurve from a surface also sounds like what he was after.

Thanks Micheal and Burrman,

In fact the isocurve is similar to what I thought but not exactly :)
And I don't want to work like a subd model, just wanted to modify some shape. I didn't know that Tspline was just a way to convert your subd in Nurbs.
What I wanted to do is having a kind of freeform modeling without loosing the power of working with curves.
Instead of modifying the surface points you change the construction curves.

For example in the picture I made the shape with sweep, what I had in mind is that if I modify any of these curves after the sweep is done, the other curves follow the modification to fit.
At the moment I can do it manually and it allow me to have simple shape construction and a great amount of control while still having perfect surface curvature.

Hi David,

> For example in the picture I made the shape with sweep, what I had in mind is that if I modify any of
> these curves after the sweep is done, the other curves follow the modification to fit.

Well, you can modify the curves right after doing the sweep, and have the sweep surface itself recalculate and update, but it's the generated surface that will get recalculate, not other curves.

It's not really clear to me exactly how you would expect the other curves to update when you change some other curve - unlike the surface that is generated from curves the other curves are usually just drawn in each individually and don't usually have any kind of special connection to one another...

- Michael