I've recently come into possession of a number of NECA 1/4 scale Predator figures, including the "classic" Jungle Hunter from the first movie with the "closed mouth" head. I've wanted to make a bio mask/helmet for it since I got it, and have spent quite some time trying to find a suitable 3D model to base it on. After much searching around and a number of false starts with low poly models I finally stumbled across a "pepakura" file designed to be printed on paper and cut out to make a full size helmet. Converting to a useable format for 3D modelling took a little time, but I was finally able to get it into Sketchup and start tinkering with it to try and make it suitable for printing in 3D.

I already had a rough mesh of the head from the closed mouth Predator that I'd created using 123d Catch on my phone, and sized in Sketchup to be as close to the physical version as possible. Using this I was then able to scale the pepakura mesh to the head, leaving a little room to try and fit it onto the figure when printed - it won't be perfect as the slightly open jaws don't allow the mask to fit closely to the head, but it should be good enough from a distance not to be noticeable, and besides the figure has two open hands that can be used to pose him in the process of taking the mask off.

First up the initial pepakura file converted to 3DS format and then imported, and scaled to fit the head mesh:



The an inner shell was added at 1.5mm thickness and manually linked to the outer shell.



The low poly mesh was then exported to MeshLab and sub divided into more faces, then a smoothing function run to reduce the faceting and give it a more natural, organic look.



This was almost ready to print, and then I came across a photo of a prop replica showing details on the inside of the mask and decided I'd try to add a few of them - as this mask will be 1/4 scale it didn't need to be an exact duplicate, just enough to add some rough details.



This is still very much in progress, so far some ridges have been added to the top surface and a block added to the face area. Next I'll add some hoses and a few more details so I'm happy to go ahead with the final print.



Once the inner details are completed the mesh will be exported, checked for any issues, and then prepped for printing at work. I should be able to schedule it in next week


UPDATE: Got a little further with the internal details, ribbed hoses added on each side.