Cleaning up a 3D scan with Meshmixer
Today we’re going to take a look at how we can use Meshmixer to clean up a 3D scan. There are loads of other things that this compact piece of software can do such as 3D printing, designing or adapting objects, sculpting and many other things. But in this article we’ll run through how to clean up an existing mesh created from a scan. I also want to take this opportunity to thank Artec 3D for their 3D scan of the head.
Get your object in the right place
The first thing to do is to transform your object so that it’s in the right place in your 3D space. Do this by using the menu on the left-hand side and selecting Edit, followed by Transform. Up will pop the properties panel to enable you to specify things like translation, rotation, scaling, and so on. Alternatively, you could use the transform widget in the interface to transform your object. Accept the transform. You may also want to use the Edit > Align tool.
Getting your object in the right place will help as you make edits to it
Quickly cutting out the rubbish
If you want to get rid of elements in your model or you want to create a flat surface pedestal for printing then you’re going to need to make use of the Edit > Plane Cut tool. When entering the tool, it’ll automatically give you a plane which you can transform with the widget. Alternatively, you can draw a red line between two points and Meshmixer will create the cut. Finally, accept the cut.
The Plane Cut tool enables you to get rid of a lot of unnecessary geometry in one swoop
Removing specific parts of your model
The next step is to remove specific parts of your model that you don’t want in the final scan. These could be in your scene because the scanner has picked up something it shouldn’t have or it could just be a particularly bad scan. From the left-hand menu use the Select tool and paint onto your mesh to highlight the polygons you want to select. You can use the properties menu to change the brush. When you’re happy with your selection simply press X to delete them.
Selecting and deleting parts of your model will help with cleaning it up
Create a pedestal for printing
If you’re printing your model you’ll want some sort of pedestal for it so that it can stand freely. To add an object into your scene simply go to Meshmix on the left-hand menu and drag and drop your desired shape into your scene. Depending on the scale of your scanned object the pedestal may be far too big for what you want. By default, the Transform properties panel comes up which enables you to scale it, move it, or rotate so that it’s in the right place at the bottom of your object.
Creating a pedestal will enable your scanned object to stand freely if you end up printing it
Join the pedestal to your scanned object
First of all, you’ll need to select both your objects by using Shift and selecting each object. A number of options will appear including Boolean Union. If you select this one you’ll end up with the two objects joined together. We’re not going to be printing this head so don’t need a pedestal. Instead we’ll continue with cleaning the model up for using later.
Joining the pedestal to the scanned object will ensure they print together
Separating your object
When you scan an object, you may find that the resulting mesh is split up into many different shells. These are often stray pieces of geometry that have been created that you really don’t want in your final mesh. A great way to get down to just your main shell is to use the Edit > Separate shells tool. When used, this will give you all the individual shells in the Object browser which you can then select and delete.
Get rid of all the stray pieces of geometry
Sorting out holes
Start by selecting the polygons that surround your unwanted hole. Up will pop a new menu which will include a sub-menu called Edit. If you go in there you’ll find the Erase & Fill tool. Click this and you’ll see your hold magically filled. You can also fill all large holes by going to Edit > Make solid.
Get rid of all unwanted holes with a couple of simple tools
Smoothing your model
Depending on the level of detail that your scan was set to, you may find that the resulting mesh is full of undesired ridges and jagged geometry. If that is the case you can make use of Meshmixer’s sculpting tools. Simply go to Sculpt > Brushes > Brushes > Robust Smooth.
Smooth over that bumpy geometry with the sculpting tools
Fix any final issues
If you’ve gone through the above steps then hopefully you’ve gone a long way to fixing your mesh. There are a whole host of other tools which you should explore and will no doubt find helpful, but hopefully this has been a good starting point. The final tool that I want to point you in the direction of will help repair any final issues with your mesh. You can find it in Analysis > Inspector. It will inspect your model and suggest any repairs. Simply select Auto Repair All to action them.
Fix any final issues with this quick shortcut
Give it a try
Meshmixer is a fantastic piece of software. It is robust, versatile, and extensive. It performs a huge variety of tasks with absolute ease and it’s never even remotely looked like crashing on me. We have to pay for a lot of Autodesk software which makes it great when they provide such a brilliant tool free of charge. The best way to learn Meshmixer would be to download a 3D model and just play around with the tools. You’ll soon pick it up.