All good and useful info. My problem with this model was that it couldn't be done using booleans. Because of the smooth transition from the curved neck into the flat indentation it had to be made from blended surfaces.
As Michael pointed out, the best method in the end was to break the area down into individual sections and blend them, then sweep the last bit where the profiles came together. Worked like a charm and looks lovely. As this model will be used for prototyping and not rendering it had to be solid. I did a purely sub-d version for the renders as accuracy wasn't necessary and uv-ing for texture maps was easier.

Back in the olden days, (maybe 15 yrs ago now) there used to be a modeller that used a kind of 3d version of bezier splines like illustrator. I think it was Electric Image or early Shade or somesuch. I remember you could edit the splines in 3d just like illustrator and it would constantly update a surface between them. It was very clever. So for a model like this you could literally draw the outline of the indent on the bottle surface and pull it down into it, creating the depth, all the time retaining the editing ability of the splines. No idea what happened to it though. That was back on a mac classic and long before iMac's etc.

I totally agree Roger, that's how I did that area, I broke it down into individual sheets and used filleting as Michael described previously.
I was tagging on Michaels answer to d3's question.
I try and work in solids as much as possible but some cases do require surfacing.


Cheers

@roj - the program you mentioned was Shade. It is still being produced today. I believe the current version is 10 in Japan, 9 in the US. If you're interested I got version 8.5 professional on a 3d world cover disk a few months ago. Let me find the info:

OK - the issue was number 123
you could buy it here: http://www.myfavouritemagazines.co.uk/store/displayitem.asp?sid=418&id=8991&custid=30@01@200958213@09319482

The one at the link is 8 to 10 pounds depending on where they're mailing it:

or I believe on ebay sometimes.

IHTH

"Use the Join command - once all edges of a model are joined to other edges forming a watertight closed skin, that makes the object enclose a volume and that is what makes a solid.
"


I`m not so familiar with surfaces, I have done lot`s of works with solid parts and assemblies so there are still a new area to learn :).
Can I join all in one time or do I have to go thru all one by one?

Thanks,

-d3-

Are there any options for surfaces and solid part colors?
It would be easier to see which part is in surface mode.

>>>>I remember you could edit the splines in 3d just like illustrator and it would constantly update a surface between them.>>>>>


MoI's history does this if the object hasnt been re-edited with another function yet. Look at the "6 legged pod" tutorial in the help or online to see it happen. :o

>>>>Are there any options for surfaces and solid part colors?>>>>>

Version 2 has this.

Hi d3,

> Can I join all in one time or do I have to go thru all one by one?

You can join a bunch all at once, just select everything that you want and run Join.

Edges have to be close enough together to be joined though, at a regular scale level the edges should be no further than 0.005 units apart in order for them to be joinable.

- Michael

Shades V10 looks good but isn't this a poly modeler? I'm not a poly expert but in most poly modelers if you model using splines doesn't the surface update when you tweak the spline around?

-

Hi d3,

> Are there any options for surfaces and solid part colors?
> It would be easier to see which part is in surface mode.

You mean have solids and surfaces automatically drawn in different colors?

No, there isn't anything for that because colors are already used for something different - you can apply Styles to objects so you can make visually distinctive groups for organizing your model and also set up materials to be used when exporting to a rendering program.

If objects were colored only by whether they were a solid or a surface, that would be in conflict with using colors for the style system where you are free to apply styles as you wish.

But a quick way to see if you are working with a solid or a surface is to select it and then look at its type indicator in the Properties panel in the upper right area of the window, here:



That will say "Solid" there if the selected object is a closed solid, or "Joined srf" if it is not a solid and made up of more than 1 surface joined together, or "Surface" if it is not a solid and just a single surface.

You can also use the Scene browser to select all solids, or hide solids, show only solids, etc... - to do that go to the Scene browser Types section here:



Click on the text that says "Solids" to select all solids, they will then be highlighted in yellow. Click on the eye to hide all solids, or right-click on the eye to hide everything else and only leave solids visible.

Also if you really really want different colors for solids and surfaces you can get that by selecting stuff with the scene browser there and then assigning a style. Like select all solids, and assign them Style = Orange, now your solids are displayed in orange.

- Michael

Hi Roger,

> My problem with this model was that it couldn't be done
> using booleans. Because of the smooth transition from the
> curved neck into the flat indentation it had to be made
> from blended surfaces.

Yeah in this case it would be hard to do a boolean since the indented part is so smooth with the neck, it's not a distinct enough part.

But that basically puts it into a more difficult/finicky/advanced type area of surface modeling with continuity...

That's just not really a fully implemented area in MoI yet, there's some beginnings of it but I think in v3 it should make some good progress.

One reason why I have not focused on that area so far is that I kind of expect that style of modeling to be done with a sub-d type tool instead of MoI - I've kind of put more focus on the solid modeling tools early on since those tend to be easier to use, quicker to learn, and also actually leverage more of the strengths of NURBS modeling and are more in contrast to things like sub-d tools.


> Back in the olden days, (maybe 15 yrs ago now) there used
> to be a modeller that used a kind of 3d version of bezier
> splines like illustrator.

I have a vague memory of something I think was called Pixel3D, could that be it?

- Michael

Hi Michael,

I understand what you're saying. Sub-D's are fine for continuity but not so easy when integrating into the cad world. I often get requests from my client for STEP of SAT files from bottles I've built using Sub-d's and I have to either go down the T-Slines route, which makes for mega heavy patch meshes, or completely rebuild in Nurbs. This is why I'm trying to lean more towards MOI/Rhino from the start so I can have less rebuilding to do. It's all good fun really!

The modeller with splines was definitely shade. See here:

http://en.wikipedia.org/wiki/Shade_3D

Only poly based though so no good for me either!

cheers
Roger

Hi Roger, have you actually run into difficulty with a T-splines model that was just exported as a set of NURBS patches not being acceptable because it made a really large file or something?

I mean, that is actually the main focus of T-splines, to give a sub-d workflow but make a NURBS result...

Did you maybe get something like a client that considered the t-splines output to be unacceptable because it was different from the kind of structure that they were used to?


But yeah if you want to have a final output that is structured like a more typical CAD model, then building it in NURBS from the start would help get you that result... But also for really sculptured / non-2d-profile stuff it will mean operating with a more advanced (and difficult to use, and sometimes kind of headache inducing) kind of toolset instead of the simple solid modeling toolset.

The one you have here is actually not bad at all, but if you start to have broader pieces of the model that you're trying to surface in that way with multiple simultaneous transitions and branching type stuff, all while maintaining high continuity, that's when sub-d/t-splines starts to really become a lot more efficient.

- Michael

Hi Michael,

I haven't had any 'trouble' as such, but I have had issues where my sub-d models have had to be re-edited after conversion because, for example, a circle of a set diameter was very slightly out even though it looked fine by eye. Due to the stretchy nature of sub-d's it's extremely difficult to get cad-accurate results. Bearing in mind I mainly build models of bottles, which must be symmetrical for manufacture.
For example the indentation on the bottle above is perfectly circular in the MOI one but the sub-d one is slightly off due to the difficulty of faking a boolean cut across a curved surface.

Recently a client needed to edit the radii on the neck of an odd shaped bottle that I'd build in modo. He'd specified one size that later needed changing. Normally he could just tweak this himself in something like Spaceclaim, but because T-Splines had patched over all the radii, instead of retaining them, he had to send it back to me to regenerate. He wasn't too happy about it.

I still use t-splines though as it really is very clever. I often end up with a hybrid model that has a sub-d body and a cad neck. Having MOI handy makes that kind of thing very easy. Horses for courses I guess.

cheers
Roger

>You mean have solids and surfaces automatically drawn in different colors?

Yes, something like that. Are those color options you ment available in trial 1.0 version?

Thanks,

d3

Hi d3,

> Are those color options you ment available in trial 1.0 version?

No, they're part of the new stuff that's in MoI version 2.0 .

- Michael

Hi Roger, I see, thanks for explaining it more.

Yes definitely getting things that are exactly circular is a big problem with sub-d...

If it's an exact circular hole that you need, that's something that a hybrid approach could be good with, like use sub-d/t-splines to build the full shape, convert to NURBS and then cut the hole with NURBS.

But if it's more of your main body shape that needs to have some exact circular shape, I can see that's going to be more difficult in sub-d. Sub-d is kind of more oriented towards things that are going to be more melty all over and not really having a specific radius called out.

Bottles seem to be a pretty difficult case combining a lot of different shape types...

- Michael

Its been a while since I looked at MOI, so had a play.
I do not like trying to patch up surfaces in MOI, so made a quick rebuild of the bottle/cut outs (as close as possible, albeit quickly done). I can get a G1 blend, but a G2 would require some changes to the bottle surface/cutouts.

How is that cut done?


Thanks,

-d3-

>>How is that cut done?<<

Is that a question to my post/model?

>>>Is that a question to my post/model?<<<

Yes, it was. I was wondering, have you used boolean to make the cut?
Looks fine, no bad edges when checking in 3d printing software.


Thanks,

-d3-