Still struggling with Surfacing... help needed

Hey guys -

I’ve been re-working and attempting to surface this guitar back for some time. I get busy w/ other projects and then find space to go at it again but essentially meet the same obstacles.

I believe all of my intersecting points are good (top line near the cutaway could possibly need some tweaking) but all in all, I think the framework is fairly solid.

Surface > Curve Network produces ‘ok’ results but leaves strange bits near the cutaway.

‘Patch’ seems to produce the best result (screenshot below) but there are some ‘dimples’ on the surface (as seen near the re-curve) that I’d like to smooth out.

My questions are as follows:

  1. Is there a better surfacing operation I should be using or a better method to get a smooth surface, ready for machining?

  2. Is it possible to go in afterwards and manipulate the surface (or is this the long way 'round)?

My goal is to machine this into MDF (convex) to make a mold upon which to vacu-form a 3-ply veneer for a guitar backplate.

Thanks in advance (I can up the 3dm file if it’s helpful).


I think your desired shape is too complex to represent it with one single surface and even to get created out of profile curves. Please note, that curves cannot give all information a surface requires. You can only use profile curves as reference for deviation.
This is the reason why your geometry is pretty undefined as you can see on the bad shading. There are dark and light spots almost randomly.

Its is difficult to give you concrete help without modelling it. Even more difficult it is without having a reference.

But what you usually do is to create multiple bigger surface, rectangular or fan alike, with only a few controlpoints. Then those are connected by simply blending in between them. Therefore you somehow need a context. In order to get a good reflection, your blend surfaces, which are those areas with higher curvature, have to follow a clear path and have to have smooth flows and proportions throughout the whole model. This requires well placed main surfaces.

How to place surfaces correctly is something you have to learn over a long period of time and is not related to any CAD-Platform specific feature.
As a starting point, take this link to learn more about some fundamental principle of surface modelling:

I would use your contours (or just the measured points from which you created them) solely as guides for where you want the surface to lie. Then create simple surfaces that are harmonious with the rounded shape of the instrument and adjust them to approximate the guides.

In your previous threads on this topic there were several alternative approaches, such as the suggestions by Pascal and Stratosfear. I think you need to explore those now you are finding a rectangular grid doesn’t answer.


Thanks Jeremy.
I do appreciate the info provided by Stratosfear and Pascal. The current challenge is that my ambition exceeds my skills (at this point) and I simply lack the knowledge to implement what they were putting forth. What I need is a walk-thru (point form) or a video explanation so I can learn the process.

As an example, I’m not sure how to approach / implement:

“… create simple surfaces that are harmonious with the rounded shape of the instrument and adjust them to approximate the guides.”

Back to it.

Thanks for the info and resource, Tom. I’ll take a look at the link.