Burr

Yep your quite correct but nearly all people building models of real life objects do not have the original blueprints from the manufacturer even if they do still exist somewhere. They are nearly always working from photos and inaccurate line drawings. So Michaels comment above is what you are trying to do which is constantly tweak the shape so it looks about right and nurbs is not the right choice for that kind of workflow.

For reverse engineering. If I am the creator, then Nurbs are the best tool for that situation. My curves will be my curves.

Hi Burr,

> If I am the creator, then Nurbs are the best tool for that situation.

Well, it depends on what you are trying to model...

So far in this thread no specific kinds of shapes have been shown or mentioned, so it is pretty much impossible to say whether NURBS would be best or whether something else would be best because the actual goal has just not been very clearly stated yet...

If you do have a model that is well defined by a set of profile curves, then NURBS generally works best for that kind of a thing.

If your model is more organic and less specific in form, it may not be very easy to define its shape clearly by profile curves. That's when polygon/subd style modeling methods tend to work well.

Which one is better depends on a variety of factors such as what kind of shapes are involved and what is the end purpose of the model.

- Michael

Hi all,

My area of interest is ships, and occasionally aircraft, inasmuch as they have a naval connection, with the idea of having the models turned into masters for resin castings using CNC milling and/or stereo lithography. I have been an infrequent user of Rhino for years and although happy with it overall I was never too happy with the lofting and sweeping of surfaces. I recently acquired Modo in order to try my hand on subd poly modelling but so far I found it to be far from what I feel compfortable with and the learning curve seems rather steep. However I am impressed by the rendering capabilities of Modo and I will stick to it, so that my models can be turned not only into CNC masters but also into illustrations, although I realise that there might be quite a lot of work for that to happen.

I discovered MoI at about the same time, mostly because the Rhino mesher is so bad and MoI’s seemed so much superior. I found MoI so appealing with its brilliant user interface that I bought it as well. I just love the way it works, and I have started building models with it, while keeping Rhino in the background. MoI’s lofting and sweeping seems to work much better for me than Rhino’s.

Here are examples of recent WIP models. These are made in Rhino, but they give a good idea of what I expect from MoI. For my purpose, a NURBS modeller is the tool of choice, but nice rendering is an attractive option too.

Hi JPB, some great looking results there!

Yeah from what you are showing there I would think that NURBS would be a better mechanism for you.


> I recently acquired Modo in order to try my hand on subd poly
> modelling but so far I found it to be far from what I feel compfortable
> with and the learning curve seems rather steep.

Yeah, I think it is quite easy to underestimate the learning curve required to get proficient in sub-d modeling.

One thing that is really nice with NURBS modeling is that it is able to leverage a strong element of working with 2D curves. In sub-d modeling you tend to be forced to work with a sea of 3D points more directly. They have tools for helping you to work with a large number of points, but it is a fairly difficult skill to master and it is not similar to many other kinds of tasks that you may have done before (unlike 2D curve drawing).

I've often seen people watch a 1 minute video that shows an experienced sub-d artist making a really cool monster head in about a minute starting from a box, then they think that the sub-d package is going to make it easy for them to do the same thing. But what they were really seeing there are a whole lot of advanced skills that took that artist a long time to develop...


At any rate, Modo is a pretty cool thing to have in your toolbox for rendering even if you're not going to be doing sub-d modeling. And if you do end up with a project that is better aligned to sub-d then you can dig more into learning that workflow at that point.


For the right kind of project (especially characters, faces, organic stuff like that), definitely subd is the better tool for it, but you also need to be prepared to make an investment of time with it.

- Michael

>If you gave me all the curves from the original ferrari model, MoI could surface it.
Sorry they are not the original and they need alot of work/corrections, but if someone could show me how to model just the bumper I would be more than happy. To make It easier I'm not looking for Class A Surfaces...
I can do a Lamborghini but not this one "Lol"

Hi Yannada, generally car modeling is a highly complex task. You should be prepared to spend quite a lot of time working with different techniques and studying tutorials to make progress on that.

Some links to help you get started:

http://moi3d.com/forum/index.php?webtag=MOI&msg=1267.16
http://moi3d.com/forum/index.php?webtag=MOI&msg=898.2
http://www.carbodydesign.com/tutorials/?id=1196

I think there was also some kind of book printed a few years ago about car modeling using Rhino, that may be worth checking out as well.

- Michael

Also, this is the same problem that kevjon runs into when hes faced with not being able to do his model with "NURBS".

The curves in your file when viewed with anything other than top view look like this



which in no way have anything to do with a bumper. So you'll be left with making that part up. The original ferrari plans had the curves there in their entirety, but took a long time to get them there, and therefore could create the surface you see on the car.

Reverse engineering a car from curves like this would be next to impossible, but you could get a good approxamation with Sub-D, it just wouldnt be true.

I'm not a car designer but same theories of Surface construction applies to products I design. look an iPhone for example, most people think is a brick with some fillets apply to it, for sure is not. surface curvature continuous modeling even applies to something as simple as the iPhone.
Anyhow I wish you had the time to wright some tutorials addressing topics like: G2 or G3 continuity, Tolerance settings etc.

As I said they are not the original and they need alot of work/corrections. (first you need to move views in place) Anyway is a free .eps from the net. to me is only good for some architectural drawing "Lol"

Also my two cents on Nurbs over Subds ( except if you can put your hands on Imagine and Shape from Catia)

>Also, this is the same problem that kevjon runs into when hes faced with not being able to do his model with "NURBS".

Complete nonsense.

Yanada
If you want to capture the look of that Ferrari get yourself a good polymodeller such as Modo.

Yannada, If you want to actually "make" the Ferrari, then go with Nurbs.

A sailing dinghy I am currently working on in MoI.

Brian

Nice boat modeling!

>>Yanada
If you want to capture the look of that Ferrari get yourself a good polymodeller such as Modo.

Well Modo is great Subd Modeler etc. but I'm interested making the real thing not some visuals...

>>Yannada, If you want to actually "make" the Ferrari, then go with Nurbs.

Ill leave that for pininfarina and others but I would love to see MoI involving to a great Class A Modeler.

Here is part of a Catia model inside MoI, Ill be running some tests on it when Scene browser ready. Ill be also running the same tests with StudioTools and NX ( I know it may not sound fair for MoI but the comparison will be focused only on tools that are currently supported by MoI).

Your having me on.

Your going to build a real Ferrari with MoI ?

You already have Catia and Studio Tools but you don't know how to model a Ferrari's bumper bar with MoI ?

There are quite a few jokesters on this forum.

Yes I could do it with Catia but not with MoI's current tool set. Now you can be my guest and prove me wrong. ( even if you get the shape you will probably lack of surface continuity, tangency, etc.)
I think will be crazy to ask MoI a $200 software to have tools like Catia or StudioTools, which they start @ $5000, Right?

Also try to read my post as it is and not jump to any conclusions. Just to clarify thinks I have used Catia and SolidWorks on previews jobs I never said I have Catia and Studio Tools, The Catia model is been provided and it will be used to run tests on StudioTools and NX which Ill be Beta testing on OSX.

Hi yannada, it is already pretty amazing that you can take your Catia data into MoI and that it looks so great!

I mean look at the quality of the display you're getting there just in MoI's current version.

I'd be interested if you could also show a screenshot of how that looks in Catia if you still have access to it right now.


But of course keep in mind that Catia is something like 100x the price of MoI and is not focused so much on being easy to learn and use like MoI is.

MoI is probably never going to have all the exact same functions as Catia, because of this different focus. As time goes on there will be some more and more various kinds of things that get added to MoI, but it is not too realistic to think that it will become a 100% complete replacement for Catia if you are using a lot of the advanced functions in there.

You can do a lot of interesting things with MoI in combination with Catia though even right now, like for instance you can run MoI on a netbook where there would be no hope of ever running Catia, do some simple designs really quickly and then be able to take your model data over to Catia for other stuff.

- Michael

Hi Kevin,

> There are quite a few jokesters on this forum.

I can understand that sub-d works better for your particular projects.

But you do realize that MoI is a NURBS modeler, and that this forum is about MoI, right?

So it tends to be filled with people for whom NURBS is a better choice for the particular tasks that they are doing, which happen to be different than your tasks.

That should not be a big mystery....

As you have surely noticed, I am quick to recommend sub-d over NURBS to someone if it fits their project better. That's just a practical thing, I mean I don't want someone to struggle to use MoI in a situation when another tool will work better for their project.

However, if you think that in all cases subd is superior to NURBS then I would have to say that you are very mistaken about that... Things that involve cutting holes through your shape tends to be a major disaster with subd, you can't guarantee that the shape of the hole is exact and instead you have to manipulate a big bunch of points to try and arrange them in the shape of the hole, and tweak the topology a lot to suit the hole. With NURBS you draw a profile curve (for example a circle of your exact hole diameter) and then cut your object with it and you're done. It's both faster and more accurate. The faster part is of interest to quite a variety of different people (including ones just doing rendering work), and the accurate part is of interest to people who are going to manufacture the part.

Manufactured parts tend to have a ton of these kinds of holes and fasteners in them, and when the part is actually built it is important for them to actually fit together and not to just look good in a rendering.

At any rate, if you hate NURBS so much then I'm not sure why you are hanging out on a NURBS forum?

I mean I don't necessarily blame you for not liking them, they are not the right tool for the work that you do and it can be very frustrating to attempt to use a tool for a job that it is not suited for. That does not mean that the same tool is not better for someone else who is working on a project that it is suited for though.

- Michael

>>>Hi yannada, it is already pretty amazing that you can take your Catia data into MoI and that it looks so great!
I mean look at the quality of the display you're getting there just in MoI's current version.
I'd be interested if you could also show a screenshot of how that looks in Catia if you still have access to it right now.

Is more than IMPRESSIVE you can brink heavy models like that into MoI. The first time I went a bit crazy I imported something Really Really Heavy. MoI just PUNCH through it
The display quality you know very well is the best of the best. Ill ask for Catia Screen shot just for fun...

>>>MoI is probably never going to have all the exact same functions as Catia, because of this different focus. As time goes on there will be some more and more various kinds of things that get added to MoI, but it is not too realistic to think that it will become a 100% complete replacement for Catia if you are using a lot of the advanced functions in there.

I Could not agree more. I'm just hoping the main focus for the next releases is on more advanced surfacing tools, basically what is there but more enhanced...and not rendering etc.

>>>You can do a lot of interesting things with MoI in combination with Catia though even right now, like for instance you can run MoI on a netbook where there would be no hope of ever running Catia, do some simple designs really quickly and then be able to take your model data over to Catia for other stuff.

Correct, MoI really fits the bill for conceptual work, as I said more enhancements on modeling tools and is gonna be great.