Can't edit an extruded curve?

HI all. New user of Shape3D here, and I’m getting stuck on how to approach modeling shapes that are derived from curves. So, for example, I’m trying to model an electric guitar, and my workflow goes like this:

  1. I start by drawing the shape of the guitar body with splines.
  2. Then I extrude the shape into the body.
  3. Then create all the necessary features of the body by modeling directly on it, such as:
  4. creating cavities for pickups,
  5. creating a neck pocket
  6. creating wiring cavities
  7. holes for switches and knobs
  8. creating belly-cuts and arm bevels
  9. cuts for body binding
  10. etc, etc… You get the idea

But now I want to change the shape of the body. I’m stuck. Do I really have to go back and do all that work over again each time I want to make a change to the shape of the body?

Thanks for your advise.

Hi, you do not need to remake the design all over.
To change the shape of the body you can draw shapes on a construction plane that can be used to make cut-outs from the design as shown below.
You can also use the Boolean intersect and subtract tool to modify the shape of the body. There is also a link to a short video on the subtract and intersect tool

Hi Victor,

Thanks for your reply. Yes, I do know that you can create cutouts with intersections to the body from other shapes. This is not the kind of change that I was talking about. I am talking about changing the subtle underlying curve geometry that was created by the splines. For example, in your model, there is a gentle sweeping curve that forms the waist of the guitar in the lower right of your body. What if I wanted to broaden the shape of that sweeping curve? What if I wanted to move the apex of that curve 5 mm to the right?

I’m all for direct modeling - acting directly on the geometry of bodies, but we must then have tools to make the changes we want. If splines only exist in sketches, and there’s no tool to act on the 3d extrusion of a spline, then I have to go back to the sketch and start all over.

Hi Jason, the app does not currently support history-based editing being a direct modeler.

Bodies can only be manipulated directly. It’s not possible to adjust a body through an underlying sketch except you delete the old body and extrude again after adjusting the sketch incase it’s a simple 3D object.

This feature actually comes top on our roadmap and we hope to implement it sometime soon in the future.

Here is one way to modify a splined body while still retaining the original. In this example I’m only enlarging part of the curved surface. Add a plane above the body. Project the body shape onto the plane. Rework the spline. Extrude and add it to the original body.

One thing I’ve found about direct modeling is how I need to manage my workflow. If I anticipate making surface changes then I usually make a duplicate body and save (hide) for reference. Internal details can also be duped and hidden. Worst case of course is the need to remake the entire body.


Thanks for that Victor. I’m very curious to know about this feature that’s on the roadmap. An you tell us more?

Thank you for getting back to me Jason! We plan to implement history-based editing for the app to give users more editing flexibility even though it’s a direct modeler.
This will allow manipulating a body from the previously created drawing.
At the moment there is set ETA for this feature.

Thanks Victor. That is very exciting to hear. I’m sure that will be a very welcome addition for many folks.

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