Guys,

I'm an absolute newbie to programs such as this, but I want to use it to try my hand at making some 3D models for myself.

I've been going through the tutorials that Michael has done, and all have helped me get a lay of the land in MOI.

My first real question is, I'm drawing a shape, then using the rail resolve to create the 3D element. When it sweeps it creates an outline of the shape, but I'm having two issues. One, it doesn't seem to be putting what I believe to be end caps on the object as it is rotated. Secondly, is there a way to make it create a solid shape as it does the sweep versus a hollow shape?

I found out everything seems to be hollow as I start to cut other shapes out of it and there's no "filling" inside and everything is just thin walls?

Hopefully I'm describing this correct, apologize for the lack of experience - but I'm taking my time working through the tutorials to see if this is a program that I want to use for my specific projects. Also, is there a user manual for MOI anywhere, I heard Michael was working on one, but couldn't find anything other than the PDF basics document?

Thanks.

Hi Mad Hatter, welcome to MoI!

> My first real question is, I'm drawing a shape, then using the
> rail resolve to create the 3D element.

Could you please post the 3DM file with your shapes in it as an attachment so I could examine your actual model?

It's very difficult to figure out what could be going wrong with only a typed-in text description rather than being able to examine the actual shapes.


> One, it doesn't seem to be putting what I believe to be
> end caps on the object as it is rotated.

There are some requirements that need to be fulfilled in order to get endcaps - stuff like the opening needs to be planar, and the rail curve needs to be closed.

Maybe your rail curve is not closed, if you could post it that would be one of the things that I would check.


> I found out everything seems to be hollow as I start to cut
> other shapes out of it and there's no "filling" inside and
> everything is just thin walls?

Yeah that's the kind of thing that will happen if you are working with open surfaces rather than closed solids.

It tends to be easier to work with solids instead because then when you do booleans on the solid the results will be solid pieces as well.


> Also, is there a user manual for MOI anywhere, I heard
> Michael was working on one, but couldn't find anything
> other than the PDF basics document?

Well, I'll be working soon on an updated one for v2 but there is a user manual for v1 already - just push the Help button to see it, or also it is available online here:
http://moi3d.com/1.0/docs/moi_help.htm

The PDF is the same user manual (minus the video tutorials) but arranged into one single document if you want to print it out.

- Michael

Here is the 3d file. I've used some boolean steps to shape the image after doing the rail resolve (the rail is still in place for you to see). I'll try to explain this as best I can to see if I am following your logic. If I take the rail line curve that I've drawn and draw two straight lines (almost at a right angle to each other, connecting the two ends of the current rail) that would close the rail in sort of a rounded triangle shape, which would then allow me to have the rounded shape on the outside and flat surfaces on the inner sides of the shape? Hope that made sense?

I've been recreating all your tutorial work for the past few hours, plus reading the documentation in the PDF, so when I say I'm a new to this, I'm literally 5-6 hours into my learning how to 3d model.

I figure working in solid shapes will be easier for what I need, as to do the 3D printing I want, I need to have watertight models - seems to me just one wrong connection point with non-solid shapes could ruin the watertightness of the object? By combining solid shapes then using boolean union options, I should be able to combine a bunch of solid shapes with no gaps anywhere in the model...I think.

As a side note, your tutorials are really impressive - wish there were more people doing tutorials like yours. I looked a few others, but without the voice overs to actually explain what's going on, they are a bit harder to follow.

Thanks for any help you can offer Michael.

Ryan.

Hi Ryan, thanks for posting the model, I'll take a look in a minute.

> I need to have watertight models - seems to me just one
> wrong connection point with non-solid shapes could ruin the
> watertightness of the object?

Yup, that's true but that's why there are a bunch of snapping tools in MoI so that you can draw something like a curve or a line and exactly place its starting point locked on to another existing edge or curve.

So generally you want to make sure you're snapping things together when drawing and not just "eyeballing" things and placing things approximately close to one another instead of exactly snapped on.


> By combining solid shapes then using boolean union options, I should
> be able to combine a bunch of solid shapes with no gaps anywhere in the
> model...I think.

Yup, that's a good way to work.


> As a side note, your tutorials are really impressive - wish there
> were more people doing tutorials like yours. I looked a few
> others, but without the voice overs to actually explain what's
> going on, they are a bit harder to follow.

Thanks, I'm glad they are helpful!

Yes, having the voice explanation really helps a lot - the reason why it's not done as often is it is like 10 times harder to make a video with voice because a lot of times it's easy to say things like "uhh, uhhh" too much. So it takes quite a lot of practice and different takes to make a good quality one with a voice track on it.

I'll post some more details in a minute after looking at your model.

- Michael

Thanks Michael.

I'm working under the demo version right now, as I'm so new to this I wanted to try a few programs before deciding to purchase something. So far, from the standpoint of someone completely new to 3D modeling, MoI is by far the easiest one of the packages I've messed with.

I've read on the forums that the various programs have different strenghts, and it really depends on what you're wanting to do. I'm looking to build small spaceship models for gaming, and seeing what some of the guys on here have been able to produce for similiar applications, I think MoI will work well. I still have to mess around with building panel lines into shapes and stuff as that's a critical piece of what I'm wanting to do, but it doesn't look to be to difficult with MoI.

I'll probably be spending the next few days messing with it some more and seeing what I can come up with. I'm hoping to be able to throw the couple hundred dollars your way for a full copy (MoI definately gets the most bang for the buck award).

Let me know what you'd recommend after looking at my file.

Thanks again Michael.

Hi Ryan, yeah your current part cannot be capped because it is just a open surface fragment, it is not closed in any direction.

In order for a shape to be automatically capped it has to have an edge that makes a closed planar loop which then can get sealed at the end.

So for example something shaped like this:



Can have caps applied to its ends to seal it into a solid.

Your current model is more like the following:



That only has a surface going 90 degrees instead of a full loop - it's not formed enough yet to be capped, you have to build more pieces and join them together before you can make a solid out of it.

MoI doesn't really automatically know how to turn such an unfinished fragment into a solid, it's not clear enough for it to do it automatically, you have to build it out more and fill in more surfaces to define the structure some more.


> If I take the rail line curve that I've drawn and draw two straight
> lines (almost at a right angle to each other, connecting the two
> ends of the current rail) that would close the rail in sort of a
> rounded triangle shape,

Well, maybe yes if your end result is intended to be something shaped like a partial rounded triangle shape... But you have the other half mirrored over to the other side, what is your intention for your final shape, is it supposed to be 2 separate rounded trianlge things or is this supposed to be one full shape that has a bridging connection between the halves?

Maybe you will need to give a rough pencil sketch of what you are trying to accomplish overall, it's not at all clear to me what kind of overall final shape you are trying to build.

- Michael

Yes, I just mirrored what I had, eventually it will be joined together. Let me take what you've given me, and go back and mess with this some more....

I do appreciate the help!

Hi Ryan, so you need to keep on building more pieces before you'll have a solid.

For example one way you could start to do that with what you currently have is to select 2 edges like this:



And then run the Construct > Loft command to build a surface between them:



If you repeat that on down the row there you will then gradually fill in more pieces there and you can then select those pieces and use Join to glue them together into a solid.

But this is a somewhat more tedious way to build things in little fragments like this, things can go a lot more quickly if you build your initial curve structure to have longer curves so that larger pieces of your model are built more right from the beginning.

Or because your shape here seems to have some repetition to it, building one segment as a solid and then duplicating it, then unioning those pieces together could be a good way to go.

I'll see about posting an example for that...

- Michael

Hi Ryan, also one thing I'd suggest in general is to build your model straddling the x or y grid axes (rather than just hanging out in space somewhere) so that you have a more convenient centerline to snap on to for doing things like mirroring etc...

Either that, or you can actually draw in a centerline early on as a reference as well. But having that centerline well defined and easy to snap on to can help to make sure you keep things accurate.

- Michael

Hi Ryan, so here is an example of what I mean by making larger pieces more all at once.

I started with this curve setup, which I built by mirroring your original path curve and then using Construct > Blend to make a smooth connecting curve between the pieces, and then Edit > Join to glue them together into one combined curve object:



Then I selected these 2 curves as the profiles:



And did the Construct > Sweep command to sweep those profiles along the rail to build this result:



Now that is ready to be converted into a solid (Sweep will automatically convert some kinds of things into a solid by capping the ends of a tube, but in this case it's more like the "sides of a tube" actually so this one you need to cap with one extra step) by selecting it and running Construct > Planar which will cap off planar open holes in an object, which results in this solid:



That's a file attached here as RyanModel2.3dm if you want to look at the geometry.


Now that you've got a piece built as a solid it can be more easily combined with other pieces by using booleans, like for example here I drew a polyline in the Front view:



Now you can select your solid, and run Boolean Difference and use the line as a cutting object to cut it into 2 pieces like this:



And then delete the piece you don't want:



But one of the main ways to kind of speed things up is to try and invest more time in the initial curve setup and try to build somewhat larger chunks of your model at the same time if possible.

You can kind of get an idea that if you do this with several pieces, you can form components and then combine the components together with booleans...

Hope this helps!

It takes a little while to get used to how to think strategically about how to build your model with fewer steps... One big tip though is to try to spend more time thinking about getting curves arranged and accurately placed as the starting point.

- Michael

Michael,

This helps immensely, and I truly appreciate the help. I fussed around with it for another hour or so, got 90% of what I want, then took what you had done and got 100% in about 1% of the time following your method.

I think you are right, designing in 3D takes more up front thinking and planning. Getting the layout right from the get go in your head on how to build what you want seems to be a big piece of what I was missing on this.

I'll keep playing around with this, I'm sure I'll have more questions.

Thanks again for the guidance.