Hi Bard,

> We should to take a "group" and align it with one another
> objet. This thing is impossible to do in MoI, isn't it?

It's possible in MoI right now - you just select all the objects that you wish to transform and the transformation command will work on them like a group.

For example if you have an assembly of 5 objects and you want them to stay together in the same relation, just select all 5 of them and then rotate them and they will all rotate as if they were a group.

But the main purpose of the Flow command is to deform objects to conform to the target object - if you want the objects to stay undeformed there is a "rigid" option to Flow which you can enable to do that, or possibly you may want to use the Transform > Orient command to reposition the group rather than using Flow:

See here for some details on using the Orient command:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3424.13
http://moi3d.com/forum/index.php?webtag=MOI&msg=3424.14
http://moi3d.com/forum/index.php?webtag=MOI&msg=4228.9
http://moi3d.com/forum/index.php?webtag=MOI&msg=3660.5
http://moi3d.com/2.0/docs/moi_command_reference8.htm#orient


I do plan on adding in a Group function to MoI, but it will pretty much be a convenience thing to make it a bit easier to select multiple objects by clicking on just one of them. You can already treat objects like groups in the current version of MoI just by selecting them all before you do the transformation.

- Michael

Hi Bard,

> To illustrate my problem, the mapping of the TORUS never
> arrives to the full height of the sphere or half-sphere or I
> don't arrive to have a circular deformation of the Torus on
> the sphere.

The problem you're running into there is that Flow uses the full "underlying surface" which may be somewhat more extended than what you see in its shaded result if you have done some operation that produces trimmed surfaces.

Please see this previous post for an explanation:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4442.6

Is it possible for you to post your 3DM file in addition to the screenshot? It helps to have a 3DM file so I can examine your actual model geometry.

But it looks like you're trying to use a trimmed surface as the base plane for the Flow - Flow works off of the full underlying rectangular surface and doesn't pay any attention to trims. Most of the time you will want to draw a plane for the base surface using one of the commands from Draw solid > Plane - those make simple untrimmed surfaces and for those planes Flow will be using the same thing that you see on the screen.

If you select your disc plane surface and turn on surface control points using Edit > show pts, you should be able to see what the full underlying surface looks like which is the one actually used by Flow. It's probably a bit larger than the surface so you may need to zoom out a ways to see its points.

- Michael

»It probably isn't that simple, I'm just approaching this like applying objects like a texture. ;)«

Well from my graphic design background I know: "No matter what you do – as long as it looks good" :D

So, when 2:1 is working for the looks, thats alright – It hasn't to be 100% correct – for me at least.

Yes, I have selected the option "rigid" to see, but that do the same torus with no deformation.

I see the easiness with "Flow" to do very incredible & complicated forms, and I trip over a simple Torus that doesn't want to bow like I want. That let me speechless.

If somebody arrives to bend well round, one torus on a half-sphere, I want to know the how of this miracle (lol).

Hello Michael,

Ok, it must not to use a trimmed surface, the solid/plane it's better. So, my base surface is a line circle fills by building function "Plane". I thought that was not a trimmed surface (a surface cutted, hewed).

If I draw a Solid/Cylinder & that I keep its base; this will be a solid circle or a trimmed surface?
If I see the points it's a solid surface, is that? If not, it's a trimmed surface.

Thank you, I go to test all that & read a lot of things about MoI.

So I have understood the "points" of one solid surface, and the area drawn by these points.

After others tests I understand, that "Flow" consider as "Base", any circular form, like a square (or rectangle).
So it's why, it must to take a solid/Plane for Base of the objets to deform; & not to want absolutely to use a circle; because a solid/square gives the same result.

So, to deform a single torus on a sphere or on any part of one sphere, that give results; but not the one that we would.

We cannot to curve or to round off, a simple torus, like a piece of a round shield bulging (domed, rounded).

If someboby arrives to do that with "Flow", that means that I have understood nothing.

I would like to be wrong! Because I round often objets on a spheric piece.

Hi Bard,

> I see the easiness with "Flow" to do very incredible & complicated
> forms, and I trip over a simple Torus that doesn't want to bow like
> I want. That let me speechless.

Please keep in mind that this is just the very first beta release and there is still work to be done on improving Flow.


> If somebody arrives to bend well round, one torus on a half-sphere,
> I want to know the how of this miracle (lol).

See the attached model for an example. The key things here are that both the base plane and the half sphere are basic untrimmed surfaces. The plane was created with Draw solid > plane, and the sphere was created by drawing a 90 degree arc and using the Revolve command on it, rather than using methods that would produce trimmed surfaces.

Flow works by mapping from the rectangular UV space of the base plane into the rectangular UV space of the curved target surface, and that process only works with a complete surface and does not pay attention to trimmed away areas.

This current method of flow is kind of like UV texture mapping, if you have done that before in rendering programs. It kind of works best for applying a pattern on to the target surface. If you want to apply a single object more like applying a decal to a curved surface, the next v3 beta will have a new "projective" mode which will work a lot better for that kind of use, see this previous post for an example of how that will work in the next beta:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4471.15

There are also some various bug fixes and improvements to flow coming in the next beta as well.

- Michael

Hi Bard,

If I understand what you are trying to do, I think the next Beta may be a little better suited to do more of a flow projection.
The current beta flow is sort of matching U/Vs and I see it more like spreading jelly on toast. :)

It has more to do with the way nurbs underlying structure works:


Edit : ooops silmulpost. ;)

Hi Bard,

> Ok, it must not to use a trimmed surface, the solid/plane it's better.

Yeah I recommend using Draw solid > Plane to build the base surface, it's the best way to get a simple untrimmed plane.


> So, my base surface is a line circle fills by building function "Plane".
> I thought that was not a trimmed surface (a surface cutted, hewed).

No, the Construct > Planar command builds a trimmed surface from the curves you give it, with the underlying plane surface somewhat larger in size than the curves.

All NURBS surfaces are really rectangular in nature, in order to get non-rectangular outlines there can be trimming curves on a surface that mark areas of it as holes or as cut away parts, but there is still a basic rectangular surface underneath those trim curves. But the "rectangle" that I'm talking about with NURBS can be a bendy one, it doesn't only have to be a flat plane and for shapes like a sphere some edges of the rectangle are compressed down to a point in the pole area of the sphere.


> If I draw a Solid/Cylinder & that I keep its base; this will be a solid
> circle or a trimmed surface?
> If I see the points it's a solid surface, is that? If not, it's a trimmed surface.

The caps of a solid cylinder are trimmed surfaces, they're a plane that has a circle as the outer trimming boundary.

Maybe if you could post some kind of drawing of what result you're trying to get it would help me to understand why you are trying to make a disc type surface as the base surface instead of a plane.

Usually a plane is the best base surface - Flow works by going from the rectangular UV space of the base surface mapping into the equivalent UV space of the target surface, and a plane tends to be the easiest thing to deal with the starting UV space since it naturally has a horizontal and vertical U and V directions that are easy to work with.

- Michael

Hi danperk,

> The current beta flow is sort of matching U/Vs and I see
> it more like spreading jelly on toast. :)

That's a good way of putting it! :)

Yes - the current full UV matching method is more suited for something that is intended to stretch along the entire target surface.

If you want to apply an object to a more localized area of an object the upcoming projective option in the next v3 beta is going to be a lot better for that kind of use.

- Michael

Hi Bard,

> After others tests I understand, that "Flow" consider as "Base", any
> circular form, like a square (or rectangle).
> So it's why, it must to take a solid/Plane for Base of the
> objets to deform; & not to want absolutely to use a circle;
> because a solid/square gives the same result.

Yeah the way Flow currently works is by going from the UV space of the base surface into the UV space of the target surface.

So it inherently works in a sort of 2 dimensional way, inside the UV space of each underlying surface and not really paying attention to any trim curves that may be marking areas of each surface as a hole or cut away area.


> We cannot to curve or to round off, a simple torus, like a piece
> of a round shield bulging (domed, rounded).

Again, I think that the new projective option coming in the next beta is going to be more like what you want:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4471.15

The current way Flow works you would use it more for applying a pattern that goes across the entire target surface.

- Michael

Hello Michael,

Ok, thank you for all your answers. That fits gradually in my head.
Yes, I had unterstood that "Flow" ran like the mapping UV texture.

In fact, my perception of the NURBS was wrong, I saw NURBS like a sort of Illustrator in 3D; and the verb "to trim" bad translated by me, in context of NURBS, confused me.

So, all the curves are like tensed up, drawn or bend, or stretched in a cubic or parallelepipedic space. It's why a circle needs more place than a square.
To learn that a square is a tensed surface gives me a bizarre (odd, strange) apprehension of the concrete objets that we built in 3D; it's very virtual suddenly; almost incredible.

Yes, the new projective option correspond to that I tried to do with "Flow". This last novelty goes to simplify greatly the work of modelisation. Super!

Still thanks, have a good day.

Hi Bard,

> In fact, my perception of the NURBS was wrong, I saw NURBS
> like a sort of Illustrator in 3D; and the verb "to trim" bad
> translated by me, in context of NURBS, confused me.

Actually NURBS curves are pretty similar to Illustrator curves - but with x,y,z coordinates instead of only x,y coordinates like in Illustrator.

But in order to make a surface instead of just an infinitely thin wire curve requires a different technique - instead of just a linear-like sequence of control points it instead uses a grid of points. Any single row or column of points in that grid behaves like a single curve, and the surface is basically formed by a continuous sweep of curves across the grid.


> So, all the curves are like tensed up, drawn or bend, or
> stretched in a cubic or parallelepipedic space. <...>

Actually the name for this kind of surface that is made up of a crossing network of curves like this, is a "Tensor product" surface:
http://www.ibiblio.org/e-notes/Splines/Inter.htm

So NURBS surfaces are always a rectangle by their definition, although more like a flexible rubber rectangle and sometimes one side of the rectangle can be squished down to a point.

Then in order to be able to have irregular boundaries that can't be done with a rectangle, trim curves are used - trim curves mark areas as being holes in the surface. When you do a boolean operation the surface actually stay the same and it's really just new trim curves that are calculated on them.

This structure is particularly relevant for Flow more than many other commands since Flow is based on working on the underlying surface since it works by mapping UV space from one surface to another.


> To learn that a square is a tensed surface gives me a
> bizarre (odd, strange) apprehension of the concrete objets
> that we built in 3D; it's very virtual suddenly; almost incredible.

That's not too unusual - another thing that's pretty common is that people don't like the way that solids work. A solid is when you have defined a fully connected unbroken skin of surfaces where every edge is joined to another edge. That then divides space into a volume. Pretty often people feel like that's not "really" a solid, but actually it is since if something mathematically defines a volume it's a solid regardless of people's emotional feelings... ;)

- Michael

Hello Michael,

All that!
It's interesting, but you know, I stay as a sculptor who uses his gouges, unable to machine his tools.

Young, I was good in mathematical, but now I forget same the multiplication tables. On the other hand, my head is full by quantities of words, musics & numerous perceptions; another knowledge.

I admire greatly your work of creation which I think particularly clever.

I know a little what I speak; during 6 or 7 years I tested for the computing press, all the graphic, multimedia, web, utilities, applications, since version 1.0, by exemple, Director 1.0, Freehand, Smartsketch (the first Flash), Painter, Swivell 3D, Bryce, Poser (Now Quidam3D), Amorphium, & many others which I forget names.

MoI is for me, revolutionary, or I should to say, very evolutionary. I waited a such program since a long time, same if others are absolutely incredible as 3D COAT. But I prefer always my old STRATA (New CX) or my old BRYCE 4 or 5, for the renderings.

Thanks, good day.

Thanks Bard, I'm really glad that you like MoI!

Those are some nice pieces that you have put in the gallery recently too!

- Michael

Here's a Video link example of some Flow workflow.

Be warned, there are some audio cliches, sorry!


MoI Flow WorkFlow from danperk on Vimeo.

Hello danperk,

Great tutorial, not making any assumptions on where to find scripts and keeping a measured pace. Thanks.

Nice geometric tut!

Study of one prehistorical PEDRI-CNAP. Different extruded circular texts on handles's head, are easily applied with "Flow". The right mapping angle of the surface, is automatically found by "Flow". It's simply child's play.