Hi again

I'm trying to add those little groves that you sometimes get around the edge of a bottle and the best way I can think of is just to array the shape I want around the object base. When I try this though it wont let me apply this to the surface and I don't know why. Hopefully someone out there can point me to the error of my ways and any other suggestions would be great too.

Thanks guys

Lang

Hi Lang - it looks like you're using the Array Curve command with the "Align to surface" option in it?

That keeps things vertically aligned to the surface normal at every point that the object is replicated to.

It's for things that are positioned vertical to a single base point on the surface, like see here for an example:
http://moi3d.com/forum/index.php?webtag=MOI&msg=2711.23

Your case is not like that kind of case I don't think, your object hugs the surface across a wide area of it, you probably want to make a circular array of one slanted piece, and you'll need to set the construction plane first to control the z axis that will be used for the circular array.

Check out here for a recent similar post on doing that type of thing:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5153.2

- Michael

The original array curve will use the curves normal. Then you can select the surface to use as the normal in the command.

Hi Lang, after loading your file it seems that your surface there is possibly not an actual cone, it's maybe some kind of slightly slanted thing? There is no "Cen" snap at the end so that probably means it's not exactly circular at the end and if it's not a symmetrical cone shape doing a circular array probably won't give you the right result.

If it's not an exact cone I'm not sure that any of the array tool will give you a proper result since most of them are oriented towards making a more uniform replication of an object and you will probably need a kind of non-uniform arrangement.

You may need to use the Flow command to map a flattened plane with objects on it onto your slanted surface.

Or were you intending that the piece that looks similar to a cone should actually be exactly conical and fully symmetrical? Because if that's the case you would probably want to reconstruct that piece to make it exact and if was an exact cone circular array would replicate things as you would need then.

- Michael

Hi Burr, it gets closer but I don't think it works quite right - if you look down the tip you can see there is some twisting of the fins.

Array curve copies objects from one base point to a target point along the curve - the align to surface option helps keeps things rotated so that the direction of the surface normal at the base point will be rotated to go in the direction of the surface normal at the target point, so something like a cylinder will point in the same direction but there can be a twist happening around that axis. Something that hangs off a long distance to the side of that point it can kind of swing around and that's probably not going to be good for this case here.

The shape of this part seems to be quite close to being a cone but is slanted or something and not quite an exact cone - if it was an exact cone array circular would then work.

- Michael

Hi Lang, so really I'd recommend getting that surface to be a precise cone, right now it's some kind of thing 98% close to being a cone by not quite - if you get it to be an exact cone then you can set the cplane and use array circular to get the pattern you need same as described here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5153.2

- Michael

Hi Michael

I'm sorry but I'm struggling here with the cplane as I can't seem to get my head around it. I've watched that short tutorial about array and cplane and have followed what i've seen but still can't seem to get the groves to flow around the object correctly. Can you point me in the right direction here. Have a quick look at the file i've uploaded and see if there is anything else that may be giving me grief.

Thanks again for your help

Lang

Hi Michael

Sorry just seen yours and BurrMans advice and your probably right it may be that the conical shape isn't actually symmetrical, I'll check it out.

Thanks guys

Lang

Hi Lang,

> Have a quick look at the file i've uploaded and see if there
> is anything else that may be giving me grief.

The part that's giving you grief is that your object is a kind of slightly squished semi approximation of a cone and not an exact cone, so you're not getting things that would help a lot like a "Cen" object snap - since it's only something resembling a circle at the end there and not an actual circle you don't get the center snap that would help you out the most in this case.

I'd recommend reconstructing that part of your object to be more exact - try setting the cplane on the attached file here where I've created an exact cone, you should notice that it's a lot more straightforward here, you can just snap directly on to the center of the end cap.

Actually setting a cplane would not actually help you out very much in your particular case on the "only kind of resembles a cone" anyway since a simple circular array only works for a cone shape not something kind of squished.

I had originally assumed that your object there that looked like a cone was actually a cone, so that's what drove some of my initial comments.

- Michael

It may be easiest for you to just create an initial cone and also replicate the fin piece how you want it all aligned to the world axes and then rotate that whole thing into place.

You can also construct it directly in place by setting a cplane as well though. If you wanted to that you'd probably draw in an axis line for the central line and then set the cplane to the base of that line - that will align the cplane's z axis with that line so that after that you will be drawing in that slanted orientation directly.

- Michael

> You may need to use the Flow command to map a flattened plane with objects on it onto your slanted surface.


I personally would see about using Flow get what you want.

Lang, there are going to be times when the part of a bottle or some object needs that kind of detail yet the surface is not perfect, as in completely flat or circular.

Flow will allow you to place your cutting or detail objects in a very approximate positions - and forget about that accurate cone shape.
If you can isolate the surface that makes up just that cone shape area, You may want to use the Rebuild command with the "Refit" option to make a more smoother-flowing surface for Flowing.


Ultimately, when it comes down to pre-planning a work-flow for solid modeling. You might be best served initially creating the cone/cap area with a series of Lofts. Starting with a circle and transitioning to a series of spoked shaped rings. This way, you can build exactly what you want.

In this particular case you can also use the Array / Circular ;)

Hi Pilou,

> In this particular case you can also use the Array / Circular ;)

I believe you can using a Bisector curve to get the CPlane on the correct angle to the nozzle.

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