awhile ago, using methods similar to what burrman shows, i made a car model concept using rhino 5. i wasn't worried about rounded edges. it was just for conceptual purposes. but it was very easy to do. from what i can tell, all the same tools are in moi.

i've often seen on the rhino and moi forums, people saying you can't model cars with nurbs. i'm not really sure why they say that. i haven't found it to be any trouble at all. i've never used subd. from what i can tell, subd makes rounding/blending much easier. but it makes it harder to precisely get the type of curves you want.

the main operations i used were:
curve from two views
2 rail sweep
surface from curve network

sometimes it helps to rebuild the curves after they are created. for some reason, the curves can come out with odd point distributions. this then affects the surfaces. so to get more uniform surfaces, the rebuild command is essential. you can see this with zerbra plots of the surfaces (this isn't available in moi though).

anthony

Burrman I don't know how to thank you is just what I was looking for
thanks 1000 !!

I can kindly ask you how you would replicate the beam I am attaching because it is what I find difficult.

Thanks Anthony for your support :)

I played around with this in rhino 5. i projected your curves onto 3 planes. then made new 3d curves using curve from 2 views. i then made the surfaces. when i try adding the beam you speak of, it doesn't make sense. the curves from 2 views don't intersect the surface you defined. basically it seems like the beam is over constraining the situation. not really sure what to do with it. i attached a file you can look at.

Hi PROP_DESIGN

The problem is that the bumper has a defined shape .... the problem is that the shape of the mudguard is different from the shape that I obtained with my curves .... if you see above in the attachment that I inserted in response to the very useful video by Burrman the fender has a rather particular shape (albeit a simple one) and I can't replicate that shape :)

yes i used the picture you provided to try and model it. i too can't replicate that with the curves you provided. that is what i was trying to show you in the last layer of the file i attached (labeled beam). the beam and the surfaces don't intersect. so somethings got to give. either your initial curves have to change or the beam is going to make some really funky changes.

i used the same method burrman showed. i used them years ago as well. those are standard nurbs practices. they work as long as you have good curves to start with. a different user was trying to model a boat awhile back. he had the same issues. without good starting curves, you won't get anywhere.

for complex models like the one you show, expert subd practices may be better. nurbs is good for simple stuff. but when you start getting super complicated nurbs becomes unbearable. this could be one of those cases. if you look at many modern cars, they have a lot of complex curves that would make nurbs impossible. the hovercar i showed, which was easy using these methods, is very simple. nothing complicated is going on.

what i mean is, you can define any given surface with four or five curves. using 2 rail sweep, patch, curve network, curve from edges etc... nothing is going to be exceptionally curved in multiple directions. or require tons of curves to define. it's best to sketch the curves in three different planes and use the curve from 2d. this way you can easily edit the curves. your wheel wheel shouldn't really be there. that should be the last thing you do with a split or trim command. it's also a little high. it makes the fender have an odd kink in it. but i tried to keep what you had and then add the beam. it doesn't seem possible to me.

By looking at the markup in the picture, by "Beam" I think you mean this part of the fender in the video...

Interestingly enough, it is the curvature shadow from the surface I created in the last video!

This video shows a method I learned from a user here, years ago, to create those "Creases". (The user is gone. I think it was Lyes, or one of the other monsters who have left us!)

a couple responses here too. We are modeling from "Pictures". Pictures and perspectivre ALWAYS have room for application and intent. Hard to be sure from a picture. The actual car fender in your hand, would be HUGE for you, in realizing the model!

You are "Patch modeling" in MoI. With patch modeling, you will eventually always back yourself into a corner. You will need tools to handle it, that MoI doesn't have yet. Most notably, 4 sided continuity tools. MoI currently has 2 sided.

So if you want to model like this, you need to supplement with some more tools.

I recently, and finally bought Rhino, as a companion to MoI!!!! (Hey Michael, it's not the other way around after all!!!! lol)

There are other, more advanced, and expensive surfacing solutions.

So I opened your last 3d model, and see that the "Beam" is indeed that area.

So you have 2 large surface to define your detail area. use trim on the fender twice, once with each of the large surfaces, then remove them and the cutout.

Then use blend on the 2 edges, and crank up the "Bulge amount", to generate your detail. (You will need to trim the one edge down with the other before the blend. You'll see)

Tangency will be more forgiving. With curvature will generate sharper creasing. If you needed to use G2 or more, make your cutout LARGER.....

Hope that helps.

Where I worked I used Rhinoceros 5 and I remember that there was the possibility of defining the continuities for the network of curves ... although I must tell you that a friend of mine modeled directly using a single surface and then mirrored it .... I don't remember which program was honestly but i know it modeled in nurbs ... i should ask.
I asked Michael for support who was very kind in following me in the modeling phases ..... at this point, since as it seems it is not easy to model it, I will try a different modeling approach .... for now I had to buy various programs for photo editing and I can not "afford" Rhinoceros .... so I'll try with Moi inventing something :)

Hi Tony,
I hear you on the affordability front. I Understand....

Did the crease method get you any detail you were looking for in that area?

If not, what did you want to see happen in there......

For Burrman

I can't understand what you mean .... calculate that I use an online translator and therefore I can't understand some words .... if you want you can also modify my 3dm to explain it better .... if you can and will not create problems :)

"""""""""""""I can't understand what you mean ....""""""""""""

No worries. A picture is worth a thousand words!



Please note: In the video I do it fast. I cut the surface in a place I didn't need to cut it. You would take more care to only cut the little cutout area, and not past it. To keep a quality surface!

If you will be patient you will have a cool tuto by the creator of this true gem in pure Moi Modeling!
As soon as it will be released i will post it here! ;)

And damned tutos for these other one are not more available!

And here, I open up the cut a little more:



This allows for a better G2 Crease, and more defined. It will also allow me to use a "Lessor" amount, and get more of a fade!

It should be enough to give you something to play with...

that's a cool trick burrman. i learned something new today. i used what you showed to at least get the needed curves. rhino being what it is, it screws up the blend quality. but i was able to extract the curves, delete the blend and use either 2 rail sweep or network. both produced good results.

just a note. some of the intial curves don't line up and are not in a plane. i was just trying to work with the original geometry. i had to do a lot of tricks just to get the 3d curves shown. to do this better i would make all new curves that line up properly. then use what burrman showed.

here's an update with new curves. all surfaces were made with curve network except for one. that was done with planar curves. with the updated curves you can mirror the geometry easily. i used what burrman showed to get the beam/crease/bump. i got the missing curves from that step.

Edit; fixed the curves some more. The front curve for the top of the hood is odd. It's from the original curve. It's hard to change at this point, without screwing a bunch of stuff up. But this at least gives the general idea.

In many cases I think the approach here is wrong. I would suggest that you model the whole side of the car, without wheel wells. Then you will have tangent surfaces. The fewer surfaces that you have to create, the fewer problems you will have to resolve. When you have what you want, it is simple to 'Trim' the wheel wells and doors. In the same way, it is often easier to extend a surface beyond what is desired and then 'Trim' it to get the end result. 'Network' has a tendency to go a little off at edges, especially if there is much curvature, and if you extend the surface and then cut off the area near the edge you will sometimes get a better result. Things like fender flares can be added later, and as shown, you can make a surface outside of the model that will let you use 'Blend' between that and the surface-to-keep. If you do have two surfaces that do not go together properly, try 'Project'ing curves onto both surfaces. 'Rebuild' the points on these curves, to get the minimum number that will keep the shape that you desire. Where curves come together at an intersection, adjust the points on either side of the intersection so that they will be in-line, i.e. a straight line will connect three points, the middle point on the intersection. Then you can use 'Network' and all should be good. Regretfully, it takes a lot of experience before one has a certain "feel" for the process.

As a side note. Here is a video of car surface modeling. His dialogue boxes have dialogue boxes to point to control dialogues, to get to a particular setting. He is using commands like "pull this edge to this particular point, with my specified knot weight....

https://youtu.be/sXYtVoODTYY

Dont feel bad that it is hard to recreate in MoI....

I dont have an extra 30k for this either!

Right on Tim. Here here....