Problem with filling 3d object?

[User_8134]

Hello I would like to print a pistol from my favourite game and I found out that the best way to preserve quality and to save material would be to slice the model in half and print it like that. I tried to fill in all gaps while preserving barrel tube to be hollow. One picture is pistol sliced in half with hollow points everywhere, second one is my try with various softwares to fill in holes (but I am not a 3d modelling guy) and the last picture is from photoshop just showing how I would like it to be (the black is barrel and red is rest that needs to be filled in). Any ideas? Or is there any1 who would help me ? Thanks
Hollow pistol

This is my try to make it solid https://ctrlv.cz/yLgT
This is how I would like it to look (sry for low photoshop skills :D) black → barrel = hollow, red → solid
https://ctrlv.cz/1Sg4

[MaddieG]

Sorry if I missed it, but what program are you using here?

Meshmixer may be your best bet, Maker’s Muse on Youtube has a plethora of tutorials for it.

[PlastiPrint3D]

Email it through to me at Gary@plastiprint3d.com

If you can show me which game it’s from (a screenshot will do fine) then I’ll be happy to slice it in two.

[User_8134]

Well I tried making it solid in meshmixer but it didn’t work out as intended I wrote to some company here in Slovakia where I live and I asked how much would it cost to have it fixed and they said 80€ and I think it is very expensive.