Hollow generate holes not working

[march100]

Hello, I've download meshmixer today, but when I use the hollow function, the "generate holes" is not working.

Neither I can add manually holes to my object.

Do I do something wrong or isn't it working?

I've added my object that I want to make hollow.

Thanks!

[Anonymous · Accepted solution]

The problem is that your source mesh comes with a minimal amount of triangles. That's an issue when models come from CAD applications not meant to be processed further on. For mesh processing such low poly meshes are not that optimal.

Instead Hollow computes the interior mesh based on voxelisation where each voxel cell (some 3D grid) hit by the surface results in a vertex. Therefor the interior shell is much denser.

Here I pulled apart both shells for visualisation (hitting W shows the wireframe):

Generating a drain hole needs to connect both shells with mesh. And that's where MM fails on such a harsh contrast in density.

So two things to solve this contrast:

1. Increase the density of the outer mesh. Best is to do this before running Hollow.

Hit Ctrl+A (Cmd+A on MAC) to SelectAll. Run Edit/Remesh on this selection (working settings see screenshot - Hint: Instead of processing the whole mesh and setting the parameters one by one, select a small area first and run Remesh. This is only to set proper tool parameters. When all is set cancel the tool and SelectAll to run it again)

2. Decrease the mesh density of the interior shell:

This can be done in Hollow on its MeshDensity parameter (working parameter see screenshot). Don't forget to hit UpdateHollow after that step.

Set the desired number of HolesPerHollow. Now GenerateHoles can do its job. Drag the red sphere to move a hole to its desired position.

Accepting this:

[march100]

Hello @Anonymous ,

it worked, but I've made a mistake ( a got 4 holes instead of 2).

When I try to do it again, the programm give me an error...

So, are you willing to make me a hollow object of the file? And send the stl to me, or add it as an attachement?

Holes under and at the front (under)

Hole diameter is 1 mm

Thanks a lot!

[Anonymous]

Here's a remeshed version which should work running Hollow and generating holes (if you want to place the holes differently)

Plus a hollowed version (thickness = 1mm) with holes at a diameter of 1mm.