Hi David,

> just thinking these two views would be enough.

The basic issue for your case here is that 2 views of an organic shape that has sort of localized lumpy areas and contours to it does not do very much to actually define the shape...

Sub-d or sculpting tools are a better toolset for organic shapes.

NURBS tools really shine with less organic forms where more of the entire shape is defined very well by profile curves, then you are able to use those profiles to directly construct your object and you're all done just using 2D curves only.


> In substance I was saying that I made the worst shape ever,

Well, there are certainly even worse ones than that! :) But the more sort of blobby and lumpy your end result is the less well defined it becomes from profile curves alone...

It may take you a little while to get the hang of which things work well in MoI and which things you would be better off doing in sub-d modeling instead.

- Michael

Thanks Michael, I have an other question for you, how do you convert an hard point to a soft point? You know when you construct your curve and you hold ctrl you can make a shape turn, but what if you have this sharp turn in your curve and you want to be soft? At the moment I am creating a new point and delete the old one. Is there any other way to do it?
Thanks

Hi David,

> At the moment I am creating a new point and delete the old one. Is there any other way to do it?

The way you are already doing it is currently the only way. In the future I want to add in some "point properties" that would allow you to switch a particular point between different modes but that is not set up yet.

- Michael

Hello,
Still there learning ;)

And an other batch of experimentation.
So this time I'm trying to build a simple shape to tackle the basis.
Trying to build it I encounter some issue in the process, here they are.

that's the shape I'm aiming to reproduce:


I created my curves and try to use a blend between two curve but doesn't work. I wanted to use that to manage the curvature with this function instead of having to create the curves with a loft to get the curvature. In the end I prefer to create the curves as I can modify them and see the change in the surface.



I built the shape with a loft using the curves below and then use fillet, the fillet doesn't work. It goes over the top curve and make an awkward shape.









In this one I made a fillet in the curve and add additionnal curves to create the curvature.
I wanted to have a curvature at the front and flat pannel on the side so the curves on the front are bent and straight at the back.
I created the surface using network and sweep but I have the issue circled in red in the shape, it is not smooth, the surface has some visible stepping.







Thanks

Hi David,


> I created my curves and try to use a blend between two curve but doesn't work.

It's difficult for me to give you any suggestions on why it didn't work without any more information - ideally if you could post the 3DM model file with the curves you were trying to blend that would then let me see what you were running into.

Curve blend works by creating a new curve in between the ends of 2 existing curves, note that you have to use it on an open curve if you try to do it between 2 closed curves then it's normal that it would not work because a closed curve does not have an open end on it.



> I built the shape with a loft using the curves below and then use fillet, the fillet doesn't work.
> It goes over the top curve and make an awkward shape.

It's a little difficult to say without seeing the actual geometry, but I think that's due to trying to fillet both the upper and lower edge at the same time in a situation where they are coming to a sharp angle to one another.

When you try to fillet 2 edges that come together at a sharp corner area, it's a lot more difficult situation than if they were to touch smoothly, basically the fillet surfaces do not natually align with one another and they will be of different widths where they run into each other. For this particular case where you've got a short of sharply meeting scalloped type shape you would probably be better off filleting the rectangle curves before doing the loft.

Or maybe for your case here it would be better to work on the top piece only by itself first and then work on the bottom part after the top is done.


> I created the surface using network and sweep but I have the issue circled in red in
> the shape, it is not smooth, the surface has some visible stepping.

There were some bugs in v2 that could cause stuff like that as a side effect, there were various improvements and bug fixes to Network in v3 that may have solved this case. Hard for me to say without being able to work with the model file itself though.

- Michael

Hi David, one possible approach:

Base surfaces built by Loft and some surface control point tweaking:




Surface blend between edges:




Side profile then Trim:





Another profile then sweep 2 rails:






This a sort of alternate "trim and blend" NURBS workflow which can used for stylized objects that may be difficult to create with the usual method of just using boolean cuts on a base shape. This style of NURBS modeling tends to be more complex and has a higher learning curve but it can work for more swoopy industrial design type shapes.

When you're heavily using this style of modeling the advantages of NURBS modeling are not as pronounced (as compared to sub-d modeling) as for things created using more solid modeling operations like booleans. So if your model requires a whole lot of this type of modeling you should possibly think about whether it's really better suited for doing in sub-d instead.

- Michael

Hi David, also you previously wrote:

> So this time I'm trying to build a simple shape to tackle the basis.

From a "CAD" point of view that's not really a simple shape at all, it would be hard to make a blueprint of it with dimensions on it, there's not any straight lines or things that correspond to constant radius fillets.

The less that a piece has any kind of straight lines in it at all and is all only bendy swoopy stuff, the less of a match it becomes for a CAD toolset, it becomes difficult to drive the design primarily by 2D curves.

NURBS modeling is best suited for models that can be formed by 2D curves - that's when your model will be very quickly and easily created by CAD. If your model is pretty different from that then by CAD standards it's not a simple shape at all and you may be better off doing it in an organic sculpting environment rather than in a CAD environment.

- Michael

I believe this is why a lot of our vendor / suppliers now want model files and not dimensioned prints. Consumer products (among others) have gone way over to the organic side of things.