3D printing and internal polygon removal.

[MealeaYing]

Hi everyone,
Hya ZBer!

Is it possible to remove polygons from the inside of an object where they are invisible anyway?
I want to do this for a couple of reasons:
The first is that it would dramatically reduce the polygon count on some objects (a very good thing I think).
The second is for 3D printing which I think requires non-impossible objects.

A lot of the stuff I make that I like is actually mangled and surfaces pass through each other leaving a lot of geometry submerged below the outside visible surface and that is what I want to get rid of.

So far the only way I have found to do this is with Dynamesh but I have to use colossal resolutions to get even close to the original shape and when you want a sharp angle close is no good. A half a million polygons turns into upwards of six million and the whole thing looks lightly melted.

I tried QRemesher but that didn’t work either.

Anyhow if anyone knows how to do this I would be thrilled!

Cheers!
Mealea

[Cryrid]

Dynamesh or remesh. You could keep the resolutions smaller, and then subdivide and project the details back. Decimation Master can then help cut things back down to a more acceptable file size. Also keep in mind the dynamesh project option, and that the resolution can depend on the scale of the object in zbrush. QRemesher on it’s own most likely wont work either unless the object is more simple. Instead you could dynamesh a duplicate of the mesh (dont worry about the details, just the general form), use qremesh to retopologize it, and then subdivide and project the details of the original sculpt back to the mesh.

Really though, depending on the type of printer you’re using and the type of geometry you’re talking about, you might not even have to do any retopology at all, intersecting meshes can be just fine (although decimation master can still be pretty useful when it comes to file sizes, especially if you’re using an online service that might impose size limits).

[Gordon_Robb]

Yes, I would check to see if the printer you plan to use needs this. All of the stuff I’ve done has been, by design, intersecting sub-tools. As long as they fully intersect (ie, no gaps between), you should be fine. Also, as the last poster said, if you haven’t already, use decimation master. It is a must.

[MealeaYing]

Dynamesh or remesh. You could keep the resolutions smaller, and then subdivide and project the details back. Decimation Master can then help cut things back down to a more acceptable file size. Also keep in mind the dynamesh project option, and that the resolution can depend on the scale of the object in zbrush. QRemesher on it’s own most likely wont work either unless the object is more simple. Instead you could dynamesh a duplicate of the mesh (dont worry about the details, just the general form), use qremesh to retopologize it, and then subdivide and project the details of the original sculpt back to the mesh.

Really though, depending on the type of printer you’re using and the type of geometry you’re talking about, you might not even have to do any retopology at all, intersecting meshes can be just fine (although decimation master can still be pretty useful when it comes to file sizes, especially if you’re using an online service that might impose size limits).

Yes, I would check to see if the printer you plan to use needs this. All of the stuff I’ve done has been, by design, intersecting sub-tools. As long as they fully intersect (ie, no gaps between), you should be fine. Also, as the last poster said, if you haven’t already, use decimation master. It is a must.

This is cool, I didn’t realize that “watertight” included intersecting meshs but I guess that makes sense as long as each mesh is watertight.
Decimation master and projection looks like the way to go, I am terrorizing my computer by trying to do this with dynamesh and projection (it takes for EVER and I cannot background ZBrush while its doing the projection bit), but I have a feeling that decimation master and projection will do the trick, and it seems to mangle the object less usually…

Thanks you guys, this is very helpful.

Cheers!
Mealea