Help with intersecting a tube into a plane

abronee

Hi everyone.

I want to create a tunnel there is intersected in a plane/or box, and I have been experimenting different things, but all gave me problems when creating the floor, sidewalls and the outer curvature. As you can see on the picture, I want to create a tunnel with a plane in the bottom of the tunnel, so I can extrude out the curvature on the side, as well as the rest of the ground. I really hope some of you can help me with this, it is killing me.

Thanks in advance
Newbie 

musashidan

I'm not sure if it's the basic modeling procedure you're having a problem with, but here's a simple mockup I've done to demonstrate one way to build it:

Start with a cylinder. Note: it's important to choose your sides in advance when you plan the asset. I've arbitrarily chosen 32.

Delete the polar n-gon caps>flip the faces>align the highighted 'floor' faces planar

Extrude the edges to create the highlighted faces>continue to extrude new edges and tweak geo as needed

Keep extruding edges and aligning them planar to create the asymmetry.

When modeling any seemingly complex shape, always take time to really examine/study the ref and break it down into simple geometric forms. 90% of all you model will be fundamentally composed of cubes, planes, cylinders, and spheres. There's a reason that they feature as primitives in every single 3D program.

abronee

Thanks for you help. Did you delete the bottom faces and filled the hole between the 4 vertex?

Obscura

No. It looks like he flattened them and then aligned them with the bottom edge of the cylinder. "align the highighted 'floor' faces planar"

abronee

Sorry my English is not so good. When the wanted faces is selected, how do you allign to the edge?

Obscura

First you can scale them on the vertical axis to make them flat, or press "make planar". Then move manually. At least thats how I would to it, but there might be a better way.

abronee

Yes okay, now I understand, thought there was some kind of tool for that. I'm not sure how he is extruding like that, when I extrude out it looks like this 

abronee

k

abronee

Sorry this one

abronee

Also, I am getting this weird artifact, even tho the geo seems right

musashidan

Obscura said:

First you can scale them on the vertical axis to make them flat, or press "make planar". Then move manually. At least thats how I would to it, but there might be a better way.

Yes, these 2 methods and Align x/y/z, Straighten within the Loop Tools, or simply remove the edges/verts in between, are how it's done in Max. I think Maya has an average planar tool as well.

When extruding edges like this, don't worry too much about how they extrude out as you'll be fixing them by aligning edges planar and moving them into position just like you did above

In your last image that's a smoothing issue. In Maya you can make edges hard/soft to fix it.

https://www.youtube.com/watch?v=yv1PQf_j3zY

abronee

The curvature around your tunnel looks precisely round, how do i achieve this so the "outer" circle, does not looks offnt loo

musashidan

It should be the exact same curvature as you extruded the edges directly from the existing cylinder.

If you've adjusted the edges that you extruded to have unequal spacing(which you have) then this will obviously upset your curvature. Try to space them evenly before you extrude.

abronee

Did i get it right ?

musashidan

Have a look at your reference again. You will see that both sides of the floor up to the platform are not the same.

abronee

Is there a way I can get rid of the triangle, I am having issues with non-manifold vertex' also

Obscura

The triangle is totally fine.

abronee

But when I am trying to smooth the edges, I am getting weird artifacts around the triangle?

Obscura

Show an image of the artifacts.

musashidan

Yes, the triangle is no problem. Are you talking about surface shading or sub-d smoothing?

abronee

So, I have a questions regarding creating this inner walk-path in the tube. My original thought was to move the the edge to a 90 degrees angle and then extruding the face out or is there any better way to do, if it is best to avoid overlapping existing geometry that there is below it (in terms of greating support edges etc.) 

Secondly, is it fine closing the environment (since its underground), with just simple planes?