I'm trying and failing with trying to create a watch body

i create a general shape with lofts but when I trim I get holes in the resultant object

am i using the wrong approach?

Also when I extrude a planer object then make cuts/trims the resultand object ends opened

oh planer extruded object

Hi Corzair - the problem is some of the points of your watch body surface are collapsed together at this spot:



Pinched-together points like that tend to create problems for intersection calculations which are used for trimming and boolean operations. There is special stuff in place to handle the case where all the points for an entire surface edge are pinched together, like at the pole of a sphere, but here you only have some of the points of an edge pinched together, not all of the points for the whole edge.

I think you'd be better off with a sort of different approach - instead of trying to build the whole watch body all in one loft, you'll need to build it more in pieces and use filleting to make rounded off corners. I'll see if I can make you an example later on today, probably a quick way to do it would be to do an extrusion from the top view and then an extrusion from the side view and intersect them to get your base shape.

- Michael

Hi Corzair,

> oh planer extruded object

This doesn't look like part of the watch, is this a different problem?

- Michael

Hi Corzair, here are some steps for a different watch body strategy.

To start with, I drew this curve in the top view - I drew the curve on the right side first, the mirrored that around the origin, and then drew 2 lines for the top and bottom parts and joined all those together:



Then I switched to the right side and drew another profile and joined those 4 segments together:



You can now construct an object from these 2 profiles using Boolean Intersection. The boolean tools know how to automatically extrude out planar curves, so it isn't actually necessary to do the extrude yourself, just select the top curve, run Construct / Boolean / Isect, then select the side profile and push Done, that will give you this object:



Selecting that and filleting edges gives this:



Anyway, you can play around with the shapes to tune the result, I hope this gives you an idea of a different approach. It's generally kind of a good idea to sort of more block out a shape first and then fillet stuff to round edges later, rather than trying to loft it all in one single go.

- Michael

Hi Corzair - now I see the other part of your message:

> Also when I extrude a planer object then make cuts/trims the resultand object ends opened

That's normal for Trim, Trim will cut the surface "skin" of an object, it won't preserve a solid.

Instead of Trim, use Construct / Boolean / Diff for this - the booleans will cut a solid with a curve and leave a solid result.

- Michael

Boy, you learn something in every thread! I didn't even know you could create shapes like this with boolean intersection!

I use curves with booleans to trim and cut away all the time but I never thought of using intersections with curves (actually it's very rare, if ever, that I use intersections - always unions or subtracts for me when it comes to booleans.)

Talk about Moments of Inspiration!

-Will

PS - Goodness Michael, I hope you can get information like this in your documentation somehow so everyone using MOI can get the maximum benefit from all of MOI's tools!

Understanding what the individual tools do is one thing but knowing how to USE those tools is what seperates the average user from the power user...

Hi Will - difference and union are certainly the more frequently used booleans, intersection is definitely used less often but it is particularly handy for quickly creating the combination between 2 profiles like in this case.

You could get the same end result using boolean difference instead. For that way you would first extrude the top profile into a solid, and on the side profile you would just have the top and bottom curves, not a fully closed loop. Then you could use Boolean Difference to cut the extrusion with the top and bottom side curves, that will slice the extrusion into different solid pieces and you can throw away the extra pieces.

The intersection method is just fewer steps.

But one other cool thing about the intersection method between 2 curves is that history is active for this case, so you can tweak the curves and see the intersection result update with your curve edits. For example with this intersection (here I have moved the curves away from the centerline before doing the intersection to keep them out of the way of the solid):



Then when editing the control points of the side curve, the solid will automatically update:




> PS - Goodness Michael, I hope you can get information like this in your
> documentation somehow so everyone using MOI can get the maximum
> benefit from all of MOI's tools!

Well, I'm going to try! :) Probably it will get more fleshed out and complete over time. There will be an initial batch of stuff that will go out with V1, but it's likely that I will continue to add various tutorials online after the release of 1.0 .

- Michael

Yep, that's probably how I would have made it doing an extrusion and then subtracting out to get the desired shape!

Intersection is hella cool - I'll certainly be using it from naou awn!

Well I hope you consider PDF documentation since it's easier to print. The now defunct Eovia used PDFs for their Hexagon program AND they were able to include Quicktime movies embedded within the PDF file as tutorials - I thought that was pretty cool at the time.

A lot of companies use HTML to achieve that kind of functionality but then you can't simply print your manual...

Either way, I look forward to it!

-Will

PS - When I first tried this, it didn't work for me (the command executed but nothing resulted) I deleted those two curves and tried a simpler rectangle and a simple curved profile like your 2nd picture above - that worked?

I guess I'm asking, what are the limitations? Does both curves have to be the same size, or "cover" each other in space? I'm not sure what was wrong with my initial two shapes - I think the shape curve was longer in one direction than the profile, I probably should have attached the .3dm but it was just a quick test and I closed the file...

Hi Will, I think I'll be doing the docs in HTML and then also convert them into a PDF version that can be used for printing.

> I guess I'm asking, what are the limitations? Does both curves have to be the
> same size, or "cover" each other in space?

Just the curves should be planar, and the extrusions of the curve should intersect each other.

I'm not sure what might have gone wrong with your first attempt... Next time save off the curves and send them over and that will help!

- Michael

Glad to hear there will be a PDF for printing!

Okay will do about sending .3DMs - I think however my profile curve may not have been planar - I'll do a quick test again, this time moving a point "out of wack" from the Top view to see if that causes the object not to be generated as happened to me before.

This does bring up one point - when a command fails, MOI doesn't display any kind or warning or error message?

Granted, I'm pretty used to that now (specially with fillet!) knowing that if I don't see a "calculating..." msg, I know the command has failed - the same with other tools, but when I was working with the intersect (as would a newbie), I didn't know at first if the command had failed or if I neglected to do something. (Of course now I know the command failed.)

I know popping up a dialog to say "command failed" would get annoying on the quick fast - perhaps just some text in that status area "Failed..." or simply turning the status area yellow or a light pink if you get an error back from one of your functions.

I guess in short, I'm saying that the silent failures within MOI sometimes leaves you head-scratching not knowing what's wrong.

Deselecting all and selecting the offending object would be a great help at times too but I don't know what kind of error info you may receive back from your functions - so this might not be feasible.

Having MOI deselect your stuff may also be an annoyance, but I can't see that being any worse than running the command 2 - 3 times wondering why it's not working (which I end up doing most of the time anyway...)


-Will

Hi Will, definitely these are great ideas, I know the lack of error or just feedback in general is a problem.

I haven't quite figured out a particularly nice unobtrusive way to handle it yet, it will probably take some experimenting with a variety of methods, that's why it hasn't made it into V1. Just like you mentioned, something that whapped you in the face too much would get annoying.

One thing I have thought about is a text box in the lower-right corner of the screen, possibly even a bit wider than the side pane (imagine the Options and Help buttons sliding over to the left a bit for that).

One problem is that is can be difficult to phrase error messages or feedback with only a few words, I often times have problems with trying to squeeze very much text into just the width of the side pane... Streaming messages down to the bottom-right corner would be pretty unobtrusive, but maybe _too_ unobtrusive...

- Michael

Dunno, I've sorta got used to looking for that status line at the top ("Calculating..."), if I have to also start looking at the bottom? Dunno...

Okay!, That's it! - It's time for MOI to have Voice Prompting!


Hmmm, Majel Roddenberry hasn't had any Star Trek voice acting, or cameo parts in a while now - I'm sure she'd LOVE to lend her voice for the differing voice prompts and status msgs you may need! :-p

-Will

Probably one line is not going to cut it for many messages though...

The other thing that would be nice about an out of the way area is it would work as a general area to stream non-error supplemental information, like some commands could spit out various information about what just happened on successful operations too (think stuff like "joined 25 curves into 3 closed loops", etc... ).

It will take some experimentation to see what different approaches feel like.

- Michael

Thankyou and much appriciated help

Sorry fro the delay in responding was quite ill yesteday (flu - yuck)

getting my head around the concepts of MoI is the hard step but once you know
its really fun .

Im having difficulty knowing how or when surfaces are retain or lost but you suggestions have helped

For making PDF there is an excellent software called PagePlus by serif
which I use and does a wounderful job also the the open source Scribus but havent used this much as yet