That's great! I love nudging things :)

Now, just in case you're not sick of all my questions yet, I have another...

I guess this is still related to my background with poly-based 3d modelling.

Say in that previous file I uploaded, the engine, what if I decided that I wanted the engines to not be quite so "recessed" (or to be more recessed) in the model?

So what I'm saying here is "what if I wanted to move the following surface backwards and forwards"...



So thus I guess I mean moving the surrounding edges. Can I do that?

This is important, because it is my flow of work... I make an object that's basically what I want, and then I edit it later to make it exactly what I want.

Hi NightCabbage, you would generally make adjustments like you're talking about in a similar construction type way.

For example to "move that surface forward", you could select it, then run Construct / Extrude to build a new solid coming out from it, then select that new solid and the original one and do a boolean union to combine them together.

That kind of an approach of constructing an additional piece and booleaning it with your model would be the most regular way to do that kind of an adjustment in MoI.

But it is also possible to break things into individual surfaces and do a lot more "low level" kind of tweaks at the surface level. If you want some more information on doing that kind of a thing, check out this object repair tutorial here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17

But it does tend to be better to build your object more closely to what you want earlier on, rather than just make something sloppy and tweak it later like you might do in a polygon modeler.

If you want to do the "tweak a bunch later" kind of workflow, probably a polygon modeler is going to be a better fit with that style of modeling rather than MoI.

- Michael

Oh well that sounds good :)

I guess I'm just trying to minimise my use of booleans, because in poly modellers booleans are horrible and don't work half the time.

But if I can rely on the boolean in Moi to work all the time, then that sounds great :)

Alrighty, so I've unioned the engine block with the 4 jets.

And the 4 jets have a circular hole in them, where you can see through to the back of the engine block.

So I've selected the circles of each of the 4 engines, and used the Planar tool to create a circular plane to cover these holes.

This is good, except that these 4 circular planes are not attached to the engine...

And I don't know how to attach them. Union just removes the circles, and join won't work on objects.

So I'm wondering how I can do this?

Cabbage,
A good tip to remember with your solids also is the "Seam edge". When you create a sold to use, before you do anything, try to have that seam edge rotated out of the way of other operations. It's not a must, but in certain circumstances having 2 seam edges exactly graze along each other can cause problems. Like if you create a sphere and align some other cutting object directly on that sphere seam edge, then try to fillet that edge, you "could/may" experience poor results.

Again, just a good habit to develope when starting out.

Here's Cabbages Engine file with the Exaust turned into solids and booleaned on to the engine. I tried to disable history on all objects from the beginning. If I select just the face of one of the exausts and run shell, it appears to try and shell All the exausts. If I select all exaust faces and run shell I get a good reslt ( .1 as the defined thickness).

Seems like something is up with his model? Possibly I missed an area I should have hit disable history? I started with the model he posted.
I ran planar on the whole group of exausts to cap them off. Perhaps if I planared them seperatly. I can fool a bit more also.

Thanks for the reply!

What's Shell?

Ok so I figured that part of my problem was because I wasn't using solid objects (for the exhausts?)

And I figured out that another of my problems was that I was trying to boolean some things together when I should have been joining.

So you boolean intersecting solid objects, and you join touching lines.

Here's my new version :D

engine3.3dm

Maybe someone could check it out and see if it's done right?

Hi NightCabbage,

> I guess I'm just trying to minimise my use of booleans,
> because in poly modellers booleans are horrible and don't
> work half the time.
>
> But if I can rely on the boolean in Moi to work all the time,
> then that sounds great :)

Yeah, that's one of the major differences between NURBS modeling and polygon modeling - booleans are much more robust and you usually focus on using them as a primary method of construction in NURBS modeling.

- Michael

Hi NightCabbage,

> What's Shell?

There's some info in the help file:
http://moi3d.com/1.0/docs/moi_command_reference7.htm#shell

The help file reference index is available here for browsing:
http://moi3d.com/1.0/docs/moi_command_reference.htm, it's a good place to look if you want to get some general info on how a particular command works.


> Ok so I figured that part of my problem was because I wasn't
> using solid objects (for the exhausts?)

Yeah, usually for doing the booleans you will want to be working with solid objects instead of trying to combine a solid with a surface like you had in this case.

Normally if you do a Loft between 2 circles you should get a solid though, unless you turned off the "cap ends" option?

Otherwise, you can select them now and run Construct / Planar to cap the ends off now, or like Burr mentioned use Construct / Shell if you want to thicken the surface into a solid which will be kind of like a hollowed out cone.


> So you boolean intersecting solid objects, and you join touching lines.

Yup!

You can also use join on surfaces as well, if you have 2 surfaces that are touching at a common edge, then join will glue them together and they will then have a joined edge between them.

When you have a set of surfaces that have all edges joined to another edge, then that is what makes a solid.

It can be convenient to work with solids, because the booleans are set up to work on volumes, and determine which pieces to keep and discard based on that.


> Maybe someone could check it out and see if it's done right?

Seems to look all ship-shape to me!

To make a more complex model you just keep doing what you've been doing and adding more and more pieces.

- Michael

Thank you so much for your patience! :)

(ah, so shell is under offset - cool, I've been looking for a tool that does that!)