Help. Per model settings without cutting the mesh?

[centunesima 0]

Hi everybody. New here. A technical question:
I'm working on a model (single piece) that requires external fuzzy skin on its middle part only, the top and the bottom is no fuzzy. 
Well, i do this by adding a support blocker cube, resizing it, and making it pass through the entire model. Then I apply the per model settings to it. The only way to make it work is to set the cube to "cut mesh", but by doing so the model is sliced into 3 different volumes "joined" together (no fuzzy-fuzzy-no fuzzy). So I've got 3 bottom skin layers, infill, 3 top skin, 3 bottom skin, infill, 3 top skin and so on. These "new volumes" are not merged into one single volume. This makes the print a mess and increases both printing time and amount of printed material a lot. 20 hours for the "volumes" vs 15 for the single original one.

So, the question is: how to apply per model settings without cutting the model? 

Sorry for the long post.
Thanks.

Edited December 12, 2021 by centunesima

[ahoeben 1,963]

This is how cutting meshes work. Cura can not apply settings to a part of a model only, so internally it has to cut the model into parts.

 

One way to get much closer to what you want is to not use a support blocker cube, but load a custom piece of geometry that is modeled to overlap on precise areas only.

 

So for example if you had a cylinder object where you only want a section in the middle to be fuzzy, you could model a "sock" tube as it were that has an inner diameter that is a fraction smaller than the outer diameter of the cylinder. Then use that as a cutting mesh.

[centunesima 0]

2 hours ago, ahoeben said:

This is how cutting meshes work. Cura can not apply settings to a part of a model only, so internally it has to cut the model into parts.

 

One way to get much closer to what you want is to not use a support blocker cube, but load a custom piece of geometry that is modeled to overlap on precise areas only.

 

So for example if you had a cylinder object where you only want a section in the middle to be fuzzy, you could model a "sock" tube as it were that has an inner diameter that is a fraction smaller than the outer diameter of the cylinder. Then use that as a cutting mesh.

Got it, it is a solution I was thinking about too, but it will change and partially mess up the mesh anyway.

I've got no experience with other slicers, but I wonder if this is the same method that Prusa or Ideamaker's softwares use to locally apply textures or generate fuzzy skin. Don't think so. If there is no other way to do it in Cura, I think Cura should create it.

Edited December 12, 2021 by centunesima

[ahoeben 1,963]

I have never used other slicers, so I don't know how other slicers do it. I just use the tools that I have at hand.