Unsure on how to connect a cylinder to something like an octagon (MG 42 barrel shroud)

Hello all and thanks for reading my question:
This is my first ever 3D model and I’ve come to a problem, I’m not sure on how to proceed connecting these two parts of the barrel shroud, a cylinder and a box that should be an octagon, I guess.
I can’t even imagine in my head how to do this, I saw and looked a lot of IRL pictures but damn, I can’t figure out the shape!
3DS max render
How it should be, IRL
Close up of the muzzle/barrel shroud
Another close up

Excuse me for this thread and sorry for wasting your time.

Thanks in advance to all for your tips!

P.S. Any constructive critics are very well appreciated and welcome!

I recommend you watch my video tutorial where I cover something similar:

My other videos in the playlist will also teach you some of these basics.

Anyways, in this situation the front part of the barrel is a separate model so don’t worry about it. You want to turn a cylinder into an octagon. Now, each side of the octagon should be made up of at least three faces to give you support edges to work with so you can sharpen as you see fit. So multiply eight by three and that gives you twenty four. So create a twenty-four sided cylinder and follow what I do in the tutorial. Then adjust the shape later on as needed through moving and scaling.

Thanks for the tip. I’ll give a shot and maybe tomorrow I’ll show you what I’ve done.

Hello all,
sorry for the long time span between this post and the last but after a lot of time modeling and deleting the outcome, I managed to get a pretty decent model.
How do you think it’s coming out? What could be a smart way to subdivide this object into 180 sides on the y-axis, to match the sides of the cylinder? How could I round the selected edges without affecting most of the topology?
And last, what do you guys think about the “extra” loops on the middle - created to match the ones of the cylinder?
Sorry for the answer, like I said, that’s my first 3D model and I would like to get some positive and negative feedback from you experienced guys.
http://thumbnails111.imagebam.com/31180/3f7623311792935.jpg
Thanks for the interest!

why do you have so many subdivisions? unless that thing is going to be like a fuck huge platform the player will walk on there is absolutely no reason to have more than 16 or so. i’m not sure you can generally notice more than 12 on a cylinder at the size of a standard fps gun model anyway. i’m not entirely sure what you’re doing anyway; are those supposed to be the same piece?

EDIT: i did that in 5 minutes because i’m in a decent mood. i’m assuming that you’re trying to make that. if you seriously feel that you need a shiton of polygons either throw a turbosmooth on it, spend a shit ton of time doing it by hand (horrible idea on many accounts), or use a boolean (tutorials online; going to make a horrible mess)

https://dl.dropboxusercontent.com/u/37308078/Stuff/Merge Demo.jpg

not sure if you’ll be able to use this; it’s max 2010. i can export as fbx/obj if needed though.
https://dl.dropboxusercontent.com/u/37308078/Stuff/Merge%20Demo.max

Thanks for the reply.
The target application will be a game with max. 8-9k tris, so I’m first creating the high poly mesh, then I will optimize and maybe recreate some part of the high poly into a low poly and I will bake the details of the high poly on the low poly.

The result should be similar to this:
http://thumbnails104.imagebam.com/31194/25d1b8311934207.jpg

realized i didn’t elaberate on how i did it earlier. started with a 16 sided cylinder and a box, connected the box through the middle on the top/bottom and sides in order to line up with the sides of the cylinder and then used bridge and create poly to connect the box to the cylinder.

that’s probably twice as many polys (assuming two tris to a poly) as you need. 2k is a lot for a weapon and you’ll have to include the hands as well.

from what i’ve seen it’s generally easiest to start with a low poly, save it when you feel it’s good, and then work on the new save and bring it up to the high poly by adding detail. that way the underlying topology is the same and you don’t get weird fuck ups when unwrapping.

https://dl.dropboxusercontent.com/u/37308078/Stuff/Demo Merge01.jpg

probably should have just moved the edge verts down, rather than chamfering as that would have prevented that extra tri getting in there with no loss of detail but it’s a hard surface so it shouldn’t be an issue.

fbx this time:
https://dl.dropboxusercontent.com/u/37308078/Stuff/Merge Demo.FBX

Thanks again! The second one is what I’m looking for. I’m trying to get that shape more or less.
I will work with my model and try to get that shape.