3 circular holes along a pipe

Hi all
Please give me an advise how to make this mesh fast and with a good quality, see att. I’ve spent a lot of time using a knife tool to make those holes but i’m not satisfied with a quality. Any suggestions are very welcome.
[ATTACH=CONFIG]275018[/ATTACH]

Attachments


Here’s one example


  • started with a mesh circle, extruded it in, added a few loop cuts and then started deleting stuff
  • first 2/3 and then half because one side is mirrored and the rest is built with an array modifier which uses an object offset
  • then beveled inside corner vertex and created an edge between the faces to create a sharp edge (which you don’t seem to have)
  • extruded along Z and deleted interior faces for array to merge everything correctly
  • subdivision surface modifier, loop cuts near edges to sharpen them

tube_cutouts.blend (540 KB)

Does it have to be a SDS?
If not, here’s the “quick and dirty” version:

  • Add circle, extrude (outer or inner) to create several circular rows of mesh (for the pipe)
  • Create another mesh as “cutter”, e. g. a stretched circle. Make sure it is filled with a polygon.
  • Select the cutter, shift-select the pipe, switch to a view in which the cutter is projected correctly onto the pipe.
  • Switch to Edit Mode and do a “Knife Project”. This is roughly comparable to a boolean operation and cuts the pipe along the outline of the cutter mesh.
  • Delete the polygons of the insets.
  • Extrude the pipe.
  • Add an Edge Split modifier.

This sounds more complicated than it really is…:wink:
This will create n-gons, but this is no problem unless you try to add a Subsurf modifier.

Blend file.

Attachments


Thanks a lot for quick replies, i’ll practice both methods.

As always here I am bringing up the rear. But here’s another way.

The profiles are:

  1. starting geometry (Poor little hexagon. No one loves you but me!);
  2. with support loops added for subsurf:
  3. subsurfed level 2 with support loops slid tighter to sharpen edges,

and finally extruded with edgeloops added (on the extruded axis) to support edges.


Result: low poly, all quads.

Nice one, indeed!

I like this approach, stay with it i think, thanks for it

Really? Nobody uses Curves nowadays?


Druban, could u give me some tips how u got that mesh in stage 1

Eppo, is that just a large circle with the others booleaned out of it? Sorry if that is a dumb question but I’m just learning.

No sorry, there’s no reason for that. Closed Curves when set flat, 2D, form surface automatically. If you add more closed curves in edit mode they do what you see in image. Technically this might be boolean operation, but no Boolean modifier involved.

I believe I just made a hexagon (add circle with 6 verts) inset it, deleted the center face and then took the knife to it. Really the addition of the knife tool means that you can just sketch any kind of geometry right in.
The Looptools addon by Bart Crouch makes evening out knifed-in geometry after the fact so much easier - circle and space and boom - it looks like you really planned everything precisely. Can’t say enough good things about that suite. Alternatively you could use the mesh>transform>to sphere as well.

You might consider making a napkin sketch of what you want and working from it (although I didn’t). Just until you’re faster in Blender than on paper.

Forgive my ignorance, coming from Lightwave, I am probably making some assumptions here. It appears that you have created the ‘holes’ by adding the circles in, (I guess as additional “geometry” in edit mode), but then it seems the curve becomes a nice single N-Gon, rather than the mess of polys I get if trying to convert the resultant curve into a mesh.
I was assuming you convert to mesh, ‘outside bits’ and all, then removed those in edit mode, but then again, that seems long winded.
(In LW, I would simply boolean / tunnel the bits out of the circle I didn’t want to leave an N-Gon which I would then extrude and bevel to suit).

i’ve just made smth similar to your mesh, took for me a couple of hours :slight_smile:

Everything is slow at first even falling off a cliff.

Some things that you might not know about - ctrl click selects verts/edges between already selected and clicked.

V and Alt V splits along the selected elements in an entirely different way than subdivide. Practice using the two methods until you know immediately which one is more appropriate for your needs.

Ngons are fine. Simple recipe - keep them flat, border using I - inset to get subsurf working. If there are artefacts J connect some vertices dividing ngon into smaller ones.

After convert curves select all and hit F - that will turn unusable triangle net into one ngon. Rumours are they will change fill if not already, so soon it might be quad fill ;).
Circle C select not needed vertices, delete. Basically takes some clicks to clear things; inset corners might take some more attention - it’s not perfect on narrow angles and takes some unnecessary vertex snap-dragging after.
Of course simple plane and circles used as a knife project cut would result the same, not boolean mod. That needs solids to work.
It’s just that using Curves it’s easier to make tricky shapes.
Btw, if you set Duplication to vertices on Object tab and parent something to this object that something gets duplicated. That’s why triangle (circle as such) is there.

Are you going just for the look, or does it need to be an exact replica of that shape? Like, are you gonna 3d print it to use in some machine, or composite it next to the real thing, or show it to some group of fans that know that shape like the back of their hands; or are you just wanting to make a tube with 3 roundish slots on the sides just because?

Hmm, I must be doing something wrong.
I create a bezier circle, set to 2D and set verts to duplicate. I go into edit mode, create the 3 small circles to remove from the big one, get a bit of a mess, but they appear to be trying to boolean. However, if I go to delete the “outer” curve segments then it ‘breaks’ the effect and it doesn’t appear to have duplicated the verticies of the smaller circle onto the bigger one.
I even tried creating 3 small objects of the circles and parenting them, but again, not doing what I expected.
I have attached a zip of my test blend file, pointers would be most welcome as I am trying to migrate to Blender from LW, but right now, it’s things like this that get to me. It would be a couple of minutes work in LW. :confused:

Heh, you have to convert to mesh beforehand, as soon as you like what curves are doing - Alt-C. Clean after. And yes, it is couple of minutes work. I’d cite DruBan one more time: “Everything is slow at first even falling off a cliff.”
Sure there is more to it if you’re used to different software - while i have had brief moments in Max and Maya, i was trying out Houdini and, well, i find Blender most comfortable to be in. Probably because i spent a lot of time in it.

http://www.pasteall.org/blend/25633

Cheers!
I agree completely, comfy is where all your speed comes from, it’s one reason I have tended to abandon looking at Blender in the past, things that are ‘easy’ in LW seem a right royal pain in Blender. However, I am now unemployed and the chance of keeping my LW license current is nil, so if I want to move forward, Blender will have to be the route.
Lightwave has template and solid drill tools which would be handy for this as well, I can think of numerous ways to do it very quickly, literally a few seconds work. Maybe as Blender progresses that sort of thing will find its way into Blenders modellnig tools.
Not to say LWs toolset is “all that”, they have barely updated the modelling tools in many many years, I rely heavily on 3rd party plugins for a lot of my work.
In the end, I abandoned attempting this the way I thought it would work. I created the circles, then simply used them as a guide creating a closed bezier curve with ‘free’ handles to get the shape, not as fast as in LW, but got the job done.
Things like this though are very good for getting to grips with tools as, though it is frustrating, you find yourself experimenting, which means more time working with the toolset. If I could pull a few tools from LW into Blender, I think it would be the best of both worlds. :slight_smile: