Meshmixer 2.x - Tricky combine

[Nicolinux 288]

Hi,

I wanted to create my own yoda vase and while cleaning up this model I came across a problem with boolean combine. The eyes are separated from the rest of th bust and it looks like it might be problematic to print:

 

I'd like to be able to somehow combine the eyes or fill up the area there. Sadly while Meshmixer is a wonderful too, it is barely documented (or outdated docs) and hence quite underestimated and less fun than it could be.

I have the yoda bust and have separated the eyes (initially the model was built in such a way that the eye sockets are expanding inwards. But I don't need this).

 

The eye (left eye for example) has a weird shape:

When I try to boolean combine the eye with the rest of the bust, it looks broken.

I thought that it might be due to differences in mesh density. But when I remesh the eye, it changes the shape and adds an ugly ripple on the surface.

Ideally I'd like to make the whole thing solid and then cut out just some parts from the top of the head (in order to make room for the vase contents). But the "make solid" option in Meshmixer doesn't produce good results. The surface is rough and broken. So what to do in such a case?

 

[meshmixer 0]

you are right, the boolean did not work. You would probably need more triangles to do the boolean, the eye you have there is very low-resolution. If you switch to flat shading in meshmixer, or turn on the wireframe, you will see it is not many faces.

That is why the Remesh has "ripples" - it is a higher res mesh, but projected onto the low-res mesh you started with. The "smooth" version you see in the other images is not actually smooth (you can see the faceting in the first slice image, for example). It is just smooth shading, based on interpolating normals. So, the one with "ripples" would be a nearly identical shape when printed, even though it looks very different.

If you do want it smoother, you could run the Smooth tool on the remeshed version. I would suggest that you try to make it more spherical first. For example if you just select the back half, and a bit of the rim, and run the Smooth tool and make it very smooth, it will actually puff outwards on the back. This will be a better shape to work with.

You could also delete that eyeball entirely and put in a new sphere (it is just part of a sphere, from the looks of it). Regardless, you probably should shrink the socket to be as small as possible (or get rid of it entirely). You could use the sculpting brushes for that, or select most of it (make the selection brush large and click once in the middle, then right-drag until the orange comes out enough) and do an Erase/Fill. The issue is that the back wall is very thin, and it will be hard to get the boolean to not poke through.

You probably also need more triangles on the eyelid to get a nice-looking result from the boolean. Remesh it up to a higher resolution. Hopefully you will find that the boolean works in that case.

 

[Daid 306]

Fix horrible Type A does wonders for the yoda eyes ;-)

 

[Nicolinux 288]

@Daid: Thanks for the tip. Will use fix horribly type-a.

If you do want it smoother, you could run the Smooth tool on the remeshed version. I would suggest that you try to make it more spherical first. For example if you just select the back half, and a bit of the rim, and run the Smooth tool and make it very smooth, it will actually puff outwards on the back. This will be a better shape to work with.

Ok, tried it, but this also changes the shape of the eye piece making it smaller. I played a bit with it but couldn't have it keep the overall form.

You could also delete that eyeball entirely and put in a new sphere (it is just part of a sphere, from the looks of it). Regardless, you probably should shrink the socket to be as small as possible (or get rid of it entirely). You could use the sculpting brushes for that, or select most of it (make the selection brush large and click once in the middle, then right-drag until the orange comes out enough) and do an Erase/Fill. The issue is that the back wall is very thin, and it will be hard to get the boolean to not poke through.

Tried that too. By the way, it would be a nice idea to include some primitive models in the meshmixer menu (sphere, cube, cylinder...). Had to fire up OpenSCAD to create a sphere, export as .stl, and import in Meshmixer.

I shrunk the eye sockets and tried to boolean the sphere with the rest, but the eye lids had too few triangles so it would look ugly (the boolean did work though).

You probably also need more triangles on the eyelid to get a nice-looking result from the boolean. Remesh it up to a higher resolution. Hopefully you will find that the boolean works in that case.

Yep, tried that too. But I couldn't get it to refine the mesh without changing it. I remember I saw (you?) in this video adding triangles to a mesh without changing it. But maybe that's because the shoe had a smoot surface to begin with.