Composite shell possibilities?

[Brotron]

I was hoping for some feedback on a feature that seems well suited for slicing software but one I can't figure out how to hack. The following image shows a simple example of what I'd like to achieve. A composite shell with a controllable offset and density.

Ultimately I'd print it as a dual material for my usage, but I can think of all kinds of benefits in strength, speed, and support that would be difficult to achieve in any other manufacturing process. Is there a way to use S3d to achieve this? The option to control infill offset and thickness would be fantastic. Thanks to anyone willing to chime in.

[JoeJ]

Just use the shell feature in your CAD package. The slicer isn't going to do this if the part is modeled as a complete solid. You need to model the part as a shelled object.

[Brotron]

I'm an FX guy so I use mainly C4D and Maya sometimes Z-brush. Getting high-rez good shells with consistent thickness and clean poly flow is certainly possible but there is a lot of tedium to make it happen and once you're there it's not very adjustable. Was thinking the math for equidistant offset is much simpler a slice at a time and could be really useful, maybe some kind of boolean subtraction from the shell position?

[JoeJ]

This would literally by 3 clicks in my CAD package. Why is it so tedious? You click shell, select the thickness, and click the surface you want to shell out. Piece of cake.

[Brotron]

Sure, 3 clicks for a cylinder. But say you have a model where you have sculpted out surface detail like wood grain and thin pipes running all over the place. When you do an interior shell wall across 10s of millions of polys where the offsets overlap you have a nightmare of mesh issues. You can hollow it out in z brush but achieving a interior shell with a clean finish and a perfectly even thickness is not such a simple thing.

Here is one of my sculpts where the wood grain would break most of my attempts to to adjust the interior shell without going back into z-brush and doing a major overhaul.

[Rebekah_harper]

In AutoDesk inventor you just select the surfaces you want to remove, the software sculpts the shell at the thickness following the exterior profile.

[Brotron]

Cool, how does Inventor handle high polycount? I have shell options in Maya and C4d but what I was really looking for was a way to adjust the interior thickness when printing without a re-sculpt or adding tons of shells walls. Being able to go from an 4mm thickness to a 20 mm thickness to control weight and strength at different scales.
Blender has a mod called solidify, z-brush uses dynamesh, maya and c4d use boolean filters but these all work from a point cloud along a normal vector, and with a super high poly count all of these methods bite, plus they end up increasing the polys even more
...but when we slice it, all we are dealing with is a 2d path that is already using constructive and clipping vector plots.
Why not make it a feature, it would end up being the "go-to" software for us high detail guys.

I mean if it's only 3 clicks

[JoeJ]

No, the software slices in 2D, and you want it to be hollowed out in 3D. It is not easy for the software to do when slicing, so it needs to be done in your CAD package. Any decent CAD package can do this and the contours will follow the external surface of the model.

If you insist on using the software instead, you can just do something like 10 perimeters with zero infill percentage. Then you will only have the outer skin with no fill (but again this is in 2D, not 3D!)

[Brotron]

Yeah, the 2D, 3D thing is kinda what I just said, not getting through here... but nervermind.
Maybe you could tell me which of "any" of these decent CAD packages will bring in a 20 million polly object and generate a clean interior shell with out losing surface detail then decimate it for an optimized 3d print. I'm sure there are plenty of z-brush artists that would love to know also.