How can I fill in voids from a 3d scan in blender?

How can I fill in voids from a 3d scan in blender? I will then want to give the guy a beard and a add ship steering wheel. Any advice is much appreciated to clean up these empty voids. Here’s a little screen capture showing the model in question.

sorry but this looks like a mess

Blender cannot read your mind and blender cannot guess what is missing either !

so you have to do it manually

but first determine what if you need that many verts ?
may be decimate it a little then start filling up the missing parts

good luck
happy bl

Apologies… Im new to blender. I know how to do basic sculpting and modeling, but not sure how Id go about filling in those voids manually. Any suggestion for how to do this? Thank you so much.

Ok I’m not an expert in sculpting in blender. But what I would do is create a solid base model to fill in the holes. Then use boolean tools to mesh the scan and the base models together. You will need to smooth out the sculpt or re add in the missing detail. You may also want to try to run the model through Mesh Mixer to fill in the holes.
One feature that Blender needs is the ability to reproject from details from one sculpt to another. At the moment I don’t know of a way to do that in blender.

to modify such a model requires some advance skills!

so you should first of all learn the basics for modelling
search web for intro to 2.81 for modelling basics

then after you might be able to learn sculpting - Dynatopo ect.

good luck
happy bl

You could try Triangle Mesh Completer http://www.ae3d.ru/ (free)

Do you still have your original point data from the scan? I’d take that and remesh it with Screened Surface Poisson Reconstruction in meshlab. That does a good job on filling in holes and missing data. If that isnt an option, or it doesnt get all the holes. I would just fill it in by modeling in the missing areas, using booleans to combine, and then the new voxel remesher in 2.81.