Hi,

I'm a true beginner and have some very basic questions for a kind soul to answer (I know that google is my friend - supposedly, but there is so much material out there that it is sometime difficult to know which strategy to adopt).

I've started modelling a simple case for an HTC One and I'm not sure how to proceed next. The sides of the phone are at an angle, the corners are all rounded and the surface at the back of the phone is curved along both axis. So far, I created some ribs (in Red) and the contour of the phone (in Blue).

I thought that I could use Loft (selecting the ribs and the contour) to make the shape a solid, but nothing happens if I select Loft / Normal / Auto and I get some weird results if I use "Loose" (see picture).

I would really appreciate if someone could please point me in the right direction... The objective is to end up with a shell that can be 3D printed.

Many thanks!

Phil

Hi Phil - the Loft command only takes one set of cross-section curves and constructs a surface through that, so for doing a Loft for example you would only be able to select just the Red curves that you are showing there for making a Loft.

You're getting a weird result in your case there because Loft is trying to build a surface that swoops through each of those curves, like it's trying to go straight from one of your red curves directly to one of the blue curves. That makes the surface suddenly swoop around as it tries to use such different shapes as the same kind of cross-section.


There are other commands that take different curve structures - Network for example can take 2 sets of cross-sections that cross each other. Sweep takes cross sections plus one or two rail curves.

But really it's usually not a good idea to try and build something like what you're showing there with tight bends in the corners just out of one single surface, usually a single surface should be something more like one sheet of material that does not have any really tight bends in it. Tight bends like the corner areas you have in this case are usually better put in as initially sharp corners and then use the Fillet command to round them off, rather than trying to build a surface that directly incorporates such a tight bend in shape directly in the surface itself.

This kind of model that you happen to be targeting is actually a pretty advanced style of mdoel to work with - things that are semi blobby and melty looking tend to be difficult to create using NURBS modeling techniques and can be a better fit for a sub-d polygon type modeling environment instead.


See here for some examples of different strategies for this kind of thing:

http://moi3d.com/forum/index.php?webtag=MOI&msg=1002.2
http://moi3d.com/forum/index.php?webtag=MOI&msg=3137.1



Also another approach is to build it by Loft, but using vertically oriented sections, as shown here (this way does do it all as a single surface):
http://moi3d.com/forum/index.php?webtag=MOI&msg=6134.6

To use that method you would include a point object (created by Draw curve > More > Point) at the top in the same plane as the topmost profile, and select the point object during the Loft as well (telling the loft to end in that point), and then use Loft style = "Loose" in the Loft options. If you're going to try to build something kind of smooth and blobby all in one single surface that method taends to be the best way. See here for some more examples:
http://moi3d.com/forum/index.php?webtag=MOI&msg=6639.2
Loft to point is new in version 3 so make sure you're running the current v3 beta in order to make use of this method.


Hope this helps!

- Michael

Hi Phil,

Just expanding on what Michael explains above I thought I'd take the opportunity to show NURBS surfacing techniques using your curves to create a solid.



Cheers

@Michael & @Danny: Thank you so much for the detailed explanations. I must say that I wasn't counting on a Hollywood superproduction :-) I'm most impressed and very grateful!

I'm travelling at the moment but will spend some serious time tonight to understand and learn from all the information you gave me.

Thanks again

Phil

@Danny: Your video is brilliant and I've learned more about MOI watching it for 10 minutes than I did in the past three days. Thanks a lot.

Cheers!

Phil

You're welcome Phil, glad it helped.

Cheers

Great video, Danny. Because you explained things as you went along I understood exactly what you were doing.
Most of videos posted seem to assume a level of expertise in MOI that I don't (yet...) possess and I find them difficult, well, let's face it, pretty much impossible to follow.
Hopefully they'll slowly become more comprehensible as I become more experienced.

Mike.

Righteous video Danny. The space pilots movements really adds to kindof natural flow of the tute. (Well, good space pilot movements. I need to bring mine out and brush up a bit).

Good one.

@Mike, thanks! Unfortunately that's a common mistake with a lot of tutorial videos, people who tend to know the software well unintentionally forget the people who are just starting out. I guess explaining things as I go has to do with when I used to train Apprentices when I was on the tools.

@Burr, cheers! You have to use the Space Pilot if you have one! I've been using one since the Spaceball 4000flx I'm so used it when I'm on a foreign computer my left hand instinctively goes for the grab but there's nothing there, it's probably bordering OCD :)
-