# Modelling Gunbarrel

How would you model this gun barrel? What technique would you use?

I came across this image and tried to replicate the model, but ehm it was harder than I thought :o

I would have used to boolean modifier, applied it and then cleared up the topology. Added some support loops for a subdiv modifier. Possibly done a lowtopo and baked a normal map to it.

Here is a quick example of the workflow

### Attachments

revolverCylinder.blend (626 KB)

Thats cheating! But that would make it way easier though, thanks.

I began with the holes instead and then used an array modifier for easier modelling this is what I got from that.

That looks way better than my attempt! I knew there had to be a better way. Thanks again!

That’s a revolving cylinder, not a gun barrel.

You have the right idea with the array modifier but there seems to be some deformation.

Emil is right, you’re going to need a couple of primitives with some amount of modifiers on them that will give you that perfect control over the edge count that is essential for building a cylinder with clean topology.
Here’s just one example: .blend

The topology is not perfect but this is just a demo of what could be done in 20 minutes by using this method. Unfortunately if you’re not familiar with how modifiers work in general and why and where the edge count is important you’re not going to have an easy time.

Another way to get the outer portion:

Model one segment, array that segment as many times as needed, use simple deform to bend it into a circle, subsurf modifier. Then it’s very easy to make small adjustments to get it how you want before committing the modifiers and finishing the rest.

Image from here: http://topology-guides.tumblr.com/

### Attachments

I have to agree with Mandalorian. I’ve spent too much of my life cleaning up Boolean operations to recommend it for such a simple, regular task. The other major benefit of a modifier stack like this is how quick and flexible making changes to your model become, rather than having to do another Boolean op + cleanup, or correct a cylindrical model without breaking its curvature.

Actually, If you place edge loops appropriately you almost won’t have to clean the mesh at all after applying boolean modifiers.
I know I might be pushy with boolean operations/modifiers as an answer to any modeling problem in blender but It’s just so better than anything else. It also gives you that non-destructive control unlike the bend modifier that unfortunately bends everything and thus could potentially ruin the original shape of the object.

And when it comes to speed it beats any other method out there. I mean building polygon by polygon or strictly box-modeling is great and all but it’s severely time consuming and unreliable when working on hard-surface objects strictly using that method.

That bend or curve modifier works splendid for tires etc with evenly distributed topology. But in this case it does nothing to help solving the bullet holes. When it comes to speed, nothing beats doing Just use what ever method you can imagine and start do misstakes. Have fun

Can you post some examples if it’s not too much to ask? Til this day, i still can’t use booleans efficiently without having to clean up minor problems.

Here is my example. Left one is before boolean is applied, right on is after boolean (need to remove doubles and correct Ngons with knife) and the one at the back is the one i want (after cleaning up boolean result)

### Attachments

Bool.blend (315 KB)

I never said that you won’t have to clean up anything, I said almost! You have to read carefully next time, friend.

.blend

In the file in the first layer you’ll find one example that would be hard and kinda “stupid” to build using traditional methods and not relying on booleans. You’ll notice that once “we poke holes” onto the mesh we can kinda estimate how should topology flow. And once we adjust parameters of certain modifiers and apply boolean modifier of the main object we’ll be left with at most 5 minutes of work.
It took me 15 minutes to clean it up, but the results are astonishing If I could say so myself.

DCBloodHound, next time please give me an object that you have a particularly extra hard time with. I will gladly construct it using Boolean methods if it’s possible and if they prove to be the best approach for constructing it.

If you have any more questions, don’t hesitate to ask me, I’ll teach you everything.

Ohh yeah, I almost forgot. Here’s how to fix your “problem”

Select top and bottom faces -> extrude -> collapse.

Thanks for the help.

The collapse method isn’t working for me, this is what i get:

It creates a a circle with triangles in the middle, also the edges run from the edge of the box to the center vertex and then back to the vertices that make up the circle.

### Attachments

Bool2.blend (411 KB)

Probably meant extrude and collapse on the object before boolean, so that the boolean already has the corresponding edges there and it can carve the hole.
https://dl.dropboxusercontent.com/u/26346140/dc_bool.mp4

I see you didn’t even look at the pictures? Shame on you.

That clears it up, thank you.

I did i did, i just assumed the mesh already had boolean applied. My fault for not zooming in for a better look.

I agree. I think the idea we’re both trying to push is learn different methods of creating your mesh, then use the best method for the project at hand.

The only problem with booleans in blender for me is not being able to box out the model beforehand and change the vertex count of primitives after moving them into place if the vertex count was off when you originally added them. You can work around this limitation, but it does make the process a bit more difficult. That being said, booleans are still a great way to add hard surface details that otherwise would take much longer to make accurately. And if anyone has tips for a good boolean workflow in blender, I’d love to hear more about it.

this also in not a gum barrel , but the revolver “cylinder”

the barrel is long thin and has grooves cut on the inside for rifling