I´ve seen some cars made in Moi 3d but I myself failed miserably at it !
Although I do an awfull lot of objects in Moi 3d I dont get around
with flowing and blending rounded shapes......
Could we see a tutorial on that sort of jobs making use of Moi 3d !
How to make a basic start etc.
I do read Rhino tutorials and tutorials using polys ......
Can someone who is a wiz at it just give me a few hints !
Peter

look these tuts
http://www.etereaestudios.com/docs_html/nixus_htm/nixus_index.htm (the Making of)
and this crazy one http://www.etereaestudios.com/training_img/sentinel_tutorial/sentinel_tutorial.htm
Have fun modeling!

Hi Frenchy pilou !
I have already looked at these before .... thank you !
Its just that the tools in Moi 3d are fantastic but most does
not translate 1 : 1 !
When I did a search of the entire site before I posed this
question I stummbled over a post of Michael that he admits that
moi still lacks those blending tools one needs to make smooth transitions.
I even looked at the Audi TT / Rhino ) tutorial Michael posted ! ; )
Am looking at alias studio too to learn but those are so different
applications ...... it simply doesnt translate !
Any advice on what tool when ....
Peter

I believe that Michael gives advices to make some little pieces and put them together after
Yet Moi has yet some tools for some complex form ;)

Well its exactly those little pieces I have problems with !
When i make bigger surfaces out of small pieces with ie the network tool
I DONT get smooth surfaces !
its nice to have the tutorials and the sideremarks to tools but we simply
dont have them and stitching doesnt result for me in surfaces !
I love Moi I realy do and it does most things perfectly ... it just doesnt translate to car surface !
Peter

Hi Peter, I don't have a lot of experience with car modeling myself, so I can't really help you out very much with the whole big picture of that.

But if you do have a particular surface that is not working well for you, if you can post the .3dm file for that particular piece I could probably help you with that.

Or possibly you are running into a bug in Network, and it would help me to improve it to have an example of the problem...

But yes, in general car modeling is a pretty difficult area of modeling and MoI does not right now have a few of the tools for surface matching that tend to be useful in this area.

- Michael

Hi Michael !
thank you very much for your reply !
I dont think there are many tools missing !
What I see from most of the other big design programs
there are just 2-3 that would come handy.
maybe we could find out for V2 what would be something new
and efficient to complete it.Im not a friend of hundreds of buttons myself.
maybe there is someone out there that knows how to use the things
that are there already ... brilliantly ... so we can do it with what we have !
Yes I will post a problem that I will run into ! I just dumped all the trys I made up till
now so it will take some time....
Peter

Hi just a short example of a network that
doesnt work for me.... I just made that quickly to show what i´m running into..
Peter

Hi Peter, you can definitely get some better results with this with a bit more careful placement of your curves.

For example right off the bat I can see from a side view there is a pretty big gap between your curves:



Network will construct a surface even if there is a gap like this, but it gets kind of averaged between all the pieces, you will get better accuracy and control if you make your pieces touch.

Also even probably a bigger problem is that some of your curves meet each other in a creased manner instead of meeting smoothly. Here is a view from the front:



The yellow line there is the tangent line of your curve there - notice how it is slanted off a few degrees from horizontal? That means that your curves meet each other in sharp point there, that will certainly contribute to making your surface meet in a sharp crease since they will follow the curves.

I'll see if I can make some recommendations for how to approach this and make a smooth piece out of it.

- Michael

Hi Peter, here is the results with just a bit of quick tuning:



I joined your longer curves together, they were already matching up smoothly (looks like they were split from a single smooth original curve).

I also joined together the 2 short pieces and then turned on control points and used Transform/Align to make the 3 points around the segment join location to all be horizontal with each other so those segments were nice and smooth.

Sometimes it can also be nice to just delete the control point where 2 segments touch to fuse them into one single smooth segment.

Additionally when using align I picked location that used intersection snap to move them to be all lined up with the other curve instead of having a space between the curves there.

Then you can select all 4 of these curves and run one single Network command to create the surface I show above. These curves are attached here as car1_tweaked_curves.zip

Whenever you have a curve network that has curves with sharp creases in them, that will definitely cause sharp creases in your resulting surfaces as well.

Hope this helps, let me know when you run across other problem areas and I can see if I can give you some tips for those as well.

- Michael

Sorry Michael !
Was to fast with posting !
I did snapping but it was off i did not see it !
But even if I corrected that now .... when we see a render like this one
you can see its not very smooth !
there are hundreds of the surfaces in on object like a car !
You cant look at every point if its tangent if you are in a process
of designing something.......
Thank you
Peter

Hi Peter, is that a rendering using the updated curves that I posted?

It looks different - did you create another one using 4 different networks instead of one single big network? If so then don't do that, that will also create creasing, try to build a smooth piece all as one larger section.

What did you use for rendering? The shape that I previously posted should make a nice smooth rendering.


> there are hundreds of the surfaces in on object like a car !

Yup, that's why a car is a difficult model to create!


> You cant look at every point if its tangent if you are in a process
> of designing something.......

You don't have to look at them later if you make sure to draw them tangent in the first place.

But definitely you don't get a smooth result if you don't have smooth curves. If you want smooth things you have to make smooth curves to get them.

If you don't want to worry about making curves smooth with each other, than MoI (and actually any NURBS modeler) is just not the right tool for you, try using a subdivision surface modeler instead. One of the nice things about a subd modeler is that it kind of melts/blends polygons smoothly in all directions if the polygons are connected up to one another.

If you don't want to worry about things being smooth, that will be an easier type of modeling tool to use rather than a NURBS modeler.

- Michael

Thank you Michael for your kind help !
Yes a car is very difficult to make I found that out in nurbs !
You are right this was with 4 curves rendered in Vray /Truespace)
What i thought was what we are doing manualy aligning
points to get a smooth transition.... couldnt there be a tool that
automates these alignments. You take a point where thes curves come together and
run smooth ?
Peter

Hi Peter, yup that will be called the "Match" tool and it is definitely something that I want to add.

But even when that tool is in place, it will still be easier to get the highest quality by doing things in larger pieces rather than in small diced up patches.

- Michael

If you download the curves that I previously posted, and use them to build one Network, you should see a lot smoother rendering of that version.

- Michael

Yes you are right !
It does render nicely !
This is the tool I was thinking of !
thats one of the few things I miss in nurbs coming from
a poly and sds background . That would greatly speed up things.
As you want Moi to be precise and sometimes these creases are wanted
it would be good to let the application know that at this point or at this
edge you want a smooth transition....
Thanks very much again
Peter

A short update !
I made other shapes that way and the trick with automatically aligning the controlpoints
and making networks in one go works well !

Hi Peter, I'm glad that you are getting some better results now!

Here I'll try to describe why doing things in larger pieces makes smoother results.

Imagine you have 4 points like this:



Now imagine that you wanted to plot a curve that passes through those 4 points. Such a curve might look like this:




That's a very natural shape for just those 4 points. However, in a certain sense the shape ends very abruptly at the end point and does not have any "knowledge" of any kind of a shape beyond those end points.

So if you mirror that shape, you can see that the mirrored result is not smooth as shown here:



In a sense the mirroring is an attempt to continue the shape, but the shape itself came to an abrupt end and did not know anything about a continuation.

If instead of doing this, you take a larger point set, like this:



Then it is possible to plot a curve going through all those points, like this:




Now you can see that the curve does not have an "abrupt end" at that center axis line, it is able to see how the shape continues past that and this will create a smooth shape at that axis line instead:



This same thing comes into play when building a surface out of small pieces. A small surface piece that gets mirrored later is very similar to that first example above. Unless it is built to carefully have a mirrorable shape, it is easy for the surface to just have an abrupt stopping point and end up with a crease when it is mirrored.

Anyway, I thought I would try to explain the reason why doing things in a larger chain can help to give smoother results.

- Michael

Here is another similar example this time with surfaces being generated.

If you start with these 3 curves:



Then loft just these to get a surface:



That surface will form a crease when mirrored:



However, if you create the whole set of section curves:



And do a loft through all of these as one larger loft, you will get this smooth result:



The same effect will happen with other kinds of surfacing tools that build surfaces through your shapes, like Network for example.

- Michael

So that's why if you want something to look like one single smooth sheet, it is a good idea to model it that way too, as one single surface command instead of building it in little separate pieces.

However, it is not good to take this to the extreme and try to build your entire car out of one single surface either - when pieces change in shape quite a bit you will definitely need to try and find some natural divisions between different sections because it tends to be too hard to control a really huge detailed surface that has a lot of variation in it in one single surfacing command.

But for an area where it seems like one logical more broadly smooth piece, like your canopy part there, then that is a good candidate for building as one larger surface.

- Michael