topic Re: Need lofting advice - or is there a better way for this? in Fusion Design, Validate & Document Forum

Need lofting advice - or is there a better way for this?

jandyman — Wed, 18 Dec 2024 05:28:29 GMT

I'm trying to model a bass guitar neck with a slightly unusual contour on the back. The methods I've used the past won't work well for this one I think. I got a ways along and thought I was doing well, but I think you can see the problem here:

Here is what I'm trying to model:

I could try adding in rails to solve the issue, but that might be fairly tedious so I'm wondering whether there are approaches that would be simpler in terms of workflow. And there are a lot of experts here.

BTW, the other end of the neck is even a little trickier, but I think if I can solve the problem for one end I will have learned enough to handle the other end:

I've only tried modeling the one end so far, I am attaching the model I've created so far, which keeps it simple

Re: Need lofting advice - or is there a better way for this?

davebYYPCU — Wed, 18 Dec 2024 06:36:20 GMT

See if this works for you, (broke some of your stuff, and forgot to activate the component.)

Not much there for the other end, but this should get you there as well.

Dance around the Timeline, can answer more questions.

The other end has better flow, so looks better.

Might help....

Re: Need lofting advice - or is there a better way for this?

TrippyLighting — Wed, 18 Dec 2024 20:11:04 GMT

With the solid modeling techniques you are employing this cannot be achieved!

Model is attached for study. If you've only worked with solid modeling so far, you should have questions as I don't think this is self explanatory 😉

Re: Need lofting advice - or is there a better way for this?

jandyman — Thu, 19 Dec 2024 00:47:37 GMT

@TrippyLighting wrote:
With the solid modeling techniques you are employing this cannot be achieved!
Model is attached for study. If you've only worked with solid modeling so far, you should have questions as I don't think this is self explanatory 😉

That is super clever. I'm really glad I came to the forum. I was able to figure out what you did, but I will have to ponder how you thought to do it so I'll know to think this way when needed. I've actually encountered the surface modeling approach earlier with guitar necks, but it was in a situation that was simple enough that the solid approach worked and requires far fewer steps, so it seemed superfluous.

I do have a couple questions. When you extruded the surface (Extrude 5), I assume that was to create a surface that the loft would try to be tangent to? That leads to the question - it looks like surface lofts try to be tangent to adjacent surfaces? Because if so, that is what makes this approach work so well.

A related question would be - how do you know when to use a surface based approach? It's related to your assertion above that this result cannot be achieved with solid modeling. It's a useful thing to know, since solid modeling generally involves fewer steps.

But thank you! I wanted to up my modeling game by asking this question, and you have definitely helped me do this.

@TrippyLighting

Re: Need lofting advice - or is there a better way for this?

jandyman — Thu, 19 Dec 2024 01:04:55 GMT

@davebYYPCU wrote:
See if this works for you, (broke some of your stuff, and forgot to activate the component.)
Not much there for the other end, but this should get you there as well.
Dance around the Timeline, can answer more questions.

I'll study these. The heel one is not exactly the shape I was going for, but I will learn something anyway. The headstock end looks really good. I can see that you've used surface lofting like the other solution, so that seems a common lesson I will take away from this. I'll figure out what got broken, then learn what I can from what you've done.

@davebYYPCU

Re: Need lofting advice - or is there a better way for this?

davebYYPCU — Thu, 19 Dec 2024 01:18:12 GMT

Yes, I used your model, and worked around the problems,

Surfacing is much easier to get these organic shapes, that are parametric. (Building with smaller and more pieces)

Sculpting is not parametric but is editable.

Might help....

Re: Need lofting advice - or is there a better way for this?

TrippyLighting — Thu, 19 Dec 2024 02:30:21 GMT

@jandyman wrote:

..
but I will have to ponder how you thought to do it so I'll know to think this way when needed. ..

I've been experimenting a lot with my own and other user models over the years. This boils down to experience gained through lots of practice. After a while, you'll have a good idea of what might work, and what does not. This was my 3rd attempt with this model. They all were not radically different, just in a detail or two.

@jandyman wrote:

I do have a couple questions. When you extruded the surface (Extrude 5), I assume that was to create a surface that the loft would try to be tangent to? That leads to the question - it looks like surface lofts try to be tangent to adjacent surfaces? Because if so, that is what makes this approach work so well.

Yep, that was the idea, but when I do try to enable tangency in the loft dialogue, the loft fails. In the end, it wasn't necessary.

Sometimes, it helps to play with G1 (tangency) vs. G2 (Curvature continuity). In this case, that also makes almost no difference.

It will not make a difference in a final machined, sanded and finished guitar part 😉

@jandyman wrote:

A related question would be - how do you know when to use a surface based approach? It's related to your assertion above that this result cannot be achieved with solid modeling. It's a useful thing to know, since solid modeling generally involves fewer steps.

Practice and experience. Although, sometimes, I take that too far, I use surface modeling when it can be done simply with a solid loft. That isn't the case here, though.

I'm glad I could help!