Hi David,

> If I can add a question, is it possible to have a jiggle parameters for the array to add
> some imperfection in the placement of the objects?

There isn't currently any mechanism for doing this - it's usually not very feasible to get good results by just randomly jiggling control points around, especially if the control points are not completely evenly spaced it's easy for some of the points to have a more pronounced impact on the end result.

MoI is overall itself not focused on generating organic type shapes, usually you would want to bring your model into a different program that is focused on that type of thing to add those kinds of details, like import it into 3D Coat or ZBrush.



> And an other thing I didn't find, how do you project your curve on one side only?

You would usually just generate the projection on both sides and delete the one that you don't want. Also if you're trying to project for the reason of cutting a hole in an object using Trim, Trim has projection built into it so it's usually better to not do the projection as a separate step. When you pick which areas to discard in trim it will only use the projections surrounding those pieces.



> the same things happen with the boolean diff, the hole is occuring through the entire
> object and I would like to have a control on the depth of the cut.

For controlling the depth of a boolean, do an extrusion of your object to your desired depth and then use the extrusion as the cutting object instead of the curve as the cutting object. In the future I do want to add a "limit depth" option to the booleans that would handle this easier, but for now you just construct an extruded cutting object.

- Michael

Thanks for the answers.
About the jiggle I think it is a very specific demand and it was not about the placement of points but of curves or objects.
The great helmets have holes in front, but these holes are not made by a machines but by hands.
So what I wanted to do is to make an array of circles along curves to place the cutting objects, but I didn't want them to be at the exact same spacing.
I wanted to introduce some small differences in the spacing, not really noticeable but still present. That help to make it hand made.
But in most case I will use MOI to make "industrial" objects so that is a really specific case. I just don't have to build my medieval armours in MOI :D

About the scripts I'm not sure it will work in my case, but I found some interesting scripts along the way.

Hi David - jiggling entire objects a bit is a lot more feasible than trying to jiggle curve control points. Check out here for a randomize plug-in which you can set up which will let you do some random movement, scaling or rotation on objects, it should work to add so me non-uniformity to your cutting holes:

http://moi3d.com/forum/index.php?webtag=MOI&msg=5416.5

- Michael

Thanks Michael,

The script will do the job, an other usefull tool to use.

Still learning Moi, and still liking it, not that it goes along smoothly everytime but some headaches I could have with polymodeling are so simple here.
But I have to admit that sometimes its simplicity make things difficult, you have to make many action to get a simple result.
For example I had an hard time to cut a surface from a projected curve, I was not able to do it so I had to make a shape from the original curve and use it for a boolean diff.
But I will use this method more often as it seems to be the way to go. The downside is that it need a lot of planning and doesn't allow for a streamlined creation.
Many time I had to redo my shape because I made a mistake while constructing my shapes.

This for example, I build the flat shape from a curve but build only one half. I then made an offset shell to get my thickness but the result was not correct at the middle after doing a mirror.
There is a way to fix that or do I have to rebuild my curves? What I had in mid was to take the border edges and align them at the center and then merge the resulting shape. It's possible to do that?


Sometimes when I have finished my shape and I need to make a forgotten operation I'd like to retrieve the curves from my shape, is it possible?
I'd like to have just the exterior line to be converted as curves, but I didn't find a way to do so.

An other thing about this helmet is that I wanted to have each panel overlapping each others, like the real object. I suppose I have to do it with my curves or I can do it when my solid are built?


Here is the short lived result as I'm using the saveless version ;)
Not really happy with it but that's just an exercise and I learned a lot. That's a really simple object but it was a hard time.





One last question, is it possible to keep the object used to create a boolean and edit them while still seeing the change in the resulting boolean?
Something like meshfusion, you have a plane cutted by a cylinder and if you scale your cylinder you see the resulting boolean changing, same for any kind of boolean operation?

Hi David,

> For example I had an hard time to cut a surface from a projected curve, I was not able to
> do it so I had to make a shape from the original curve and use it for a boolean diff.

If the curve became non-planar after it was projected, that would cause that type of effect - boolean difference can only directly use 2D planar curves as cutting objects, they become extruded as a process inside the boolean.

If you want to only cut some limited distance into an object instead of all the way through then that is normal that you would build a shape from the original curve and use it for the boolean, that's the process for doing that...



> Many time I had to redo my shape because I made a mistake while
> constructing my shapes.

As you gain more experience these types of mistakes will become less common.



> This for example, I build the flat shape from a curve but build only one half. I then made an offset shell
> to get my thickness but the result was not correct at the middle after doing a mirror.

Yeah, that's just how offset geometry works - the offset surfaces generated from individual surfaces will only touch each other if the surfaces are smooth where they meet up.



> There is a way to fix that or do I have to rebuild my curves?

You can try to join the surfaces together before you do the offset - that will then make the offset surface get extended to fill in the missing area.



> Sometimes when I have finished my shape and I need to make a forgotten operation I'd like to
> retrieve the curves from my shape, is it possible? I'd like to have just the exterior line to be converted
> as curves, but I didn't find a way to do so.

You can extract edges by selecting them and using Copy/Paste to duplicate them, the pasted result will be separate curve objects.



> An other thing about this helmet is that I wanted to have each panel overlapping each
> others, like the real object. I suppose I have to do it with my curves or I can do it
> when my solid are built?

You can move the panels around after you have created them. But if the overlapping involves some kind of shape adjustment rather than just movement alone then you would want to have that set up with your curve structure instead.



> Here is the short lived result as I'm using the saveless version ;)

It turned out well!



> One last question, is it possible to keep the object used to create a boolean and
> edit them while still seeing the change in the resulting boolean?

No, not currently but that is something I want to add in the future with a deeper history mechanism.


- Michael

Hi Michael
This time I have an issue while trying to build a shape using the sweep function.
I tried to follow this thread to build my shape but I can't get the same result.

Here is my curves, following the same color code from the thread, and the result I have.









The resulting file is attached too, do you know what I did wrong?
Thanks

Check out blue and black non-intersection?

Why do you make Sweep ?
It's typical something for a Network!

I checked my intersection, I recreated the curves but there is always the same issue at the same spot. I was not able to track what is causing it.

I made a network but I had a pinching. I'll try to redo it.

Thanks for the support.


Edit: I tried to make the shape using network but it doesn't work. I get a funky shape, I have no clue what I am doing wrong.

I moved the two end points of the right hoop to intersect, and network seemed to work very well.

I have to reload my last file as I did several change.
Here is how I cut my curves, maybe I am overdoing it.
But with these curves I cannot have a proper shape from network.





Ok I was able to make the network correctly but I have pinching at the end of the shape. That's why I wanted to use Pilou technique with the sweep.

Here is what I have at the end.

Hi David, re: sweep problem,

> The resulting file is attached too, do you know what I did wrong?

It looks like the same problem from this other recent thread here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=6605.5

When you use a scaling rail the scaling rail must cover the entire extent above the rails - just making it touch the profile is not necessarily far enough if your profile is not planar and directly above the rails.

Sometimes it can be easier to construct things like this with more planar pieces like flat rails and then introduce warping later on using the Transform > Deform > Flow command (which is new for the upcoming v3 version), rather than using a lot of 3D warped rail curves from the start.

But anyway your particular sweep here can be fixed by extending the scaling rail in the side view so that it covers the entire area perpendicular above the rails like this:



And you're probably best off making the proflie for the sweep to be positioned perpendicular to the rails rather than having it start out in a slanted position, if you then want to introduce a slant at the end when you're done with the sweep use a boolean or trim to cut off the end with a line rather than trying to build a surface with slanted pieces right in the initial surface construction.

I've attached an example 3DM file here which should work better. Also I aligned the end point and first inside control points on the rails so that the curves are smooth where they touch rather than coming to a sharp angle where they connect.

- Michael

Hi David,

> I have to reload my last file as I did several change.
> Here is how I cut my curves, maybe I am overdoing it.
> But with these curves I cannot have a proper shape from network.

Yeah it looks like you've cut them up into too many little pieces there. They need to form a grid layout, but the horizontal and vertical lines of the grid (sort of like lines of longitude and latitude on a globe) need to extend across the entire grid.

There's some more discussion on the type of arrangement that Network needs in some of these previous threads:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4384.4
http://moi3d.com/forum/index.php?webtag=MOI&msg=1778.6



> Here is what I have at the end.

That kind of tip shaping tends to be a consequence of something that's not very uniform collapsing down to a single point.

To reduce it in Network it can be helpful to include a circle or arc curve near the tip so that things are more uniformly spaced just before they collapse down. See a couple of examples of that here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3623.14
http://moi3d.com/forum/index.php?webtag=MOI&msg=3550.6



It can be better in general to use more 2D construction though - revolve or rail revolve will tend to form the nicest perfectly round tips on closed objects, then in v3 there are new deformation tools that can be used to deform the smooth revolve onto a different path, see the attached example 3DM file, note here how every curve that went into making the end result was a planar curve that was flat to one of the top/front/right views, not any curves that are warped in 3D themselves. The final result has edge curves that warp in 3D but they're the result of construction from all 2D inputs...

- Michael

Thanks Michael,
I tested your file and the result with revolve rail is perfect.
One thing I'm not sure to understand is the last step. You did use flow with the blue curve to deform the resulting shape?
What is the purpose of the straight red curve?

But thanks for the tips, I will try to use it.

I'm still trying to build my shapes and that's funny how this method help me to understand better the shape, it will improve my polymodeling at the same time ;)

So here is a shape I'm trying to build.
I tried to apply the different techniques you shown me, but I have some difficutly with this case.
I build the main shape using sweep, and then I wanted to use 2D curves to cut it and produce my final result. But it didn't goes as I planned it.
When I followed my template to draw my curve on the side and cut the shape with it, the projected cut didn't follow my shape in the front view. So I tried to cut an other time in the front, but as you guessed it that didn't worked.
On the pictures I tried to make the curve in 3D and project it on the surface to trim it, but it doesn't resolve the issue.
As I understand it, it is because my volume doesn't intersect at the right place to conform my needs.

The yellow curve is what I want and the purple curve is the result.
How would you approach this?

Thanks

Edit: I found lyed helmet tutorial thread but the videos are not available, is there an other place to get them as it seems really usefull.

Hi David,

> One thing I'm not sure to understand is the last step. You did use flow with the blue
> curve to deform the resulting shape?
> What is the purpose of the straight red curve?

The Flow step used both the blue curve and also the red straight curve underneath it. That's how Flow works - it takes in a "base curve" and a "target curve", then remaps points from their relative position on the base curve onto the equivalent relative position on the target curve.

Usually the base curve will be a straight line running like a sort of backbone down the center of the thing you want to deform.


> The yellow curve is what I want and the purple curve is the result.
> How would you approach this?

It's tough for me to form a very good comment without being able to examine your actual geometry.

I'm confused as to why the projection does not match your drawn profile in the same 2D view, do you have the cutting curve placed at some kind of inclined angle or something? When you draw a 2D curve to cut with, the resulting cut in 3D should exactly match that same profile in the originating view.

- Michael

Hi Michael,

The file is at work so I can't give it to you now, sorry.
About the cut, the issue is not about the projected result from one view. The issue is when I project the drawn curve from the side view if I look through the front view the resulting cut is not matching in this view.
And if I draw the curve in the front view this will be the side view which won't match.
But I think it is completly normal as I'm projecting on a surface. That is my method that doesn't work but I don't have a clue on how to approch this.
I'm trying to make a sci fi helmet, nothing original here ;), but I don't know how to tackle this object.
It's not about tracing already accurate line work, it's about translating a 2D concept to 3D.
I made a sketch in Zbrush and then made a turntable from it, I then used the resulting image as template in MOI to try to reproduce a clean geometry.

Still a lot to learn to be proficient ;)

Hi David,

> That is my method that doesn't work but I don't have a clue on how to approch this.

I guess the usual method is to pick just one of those views, either the front or the side as being the one of primary importance and using that.

If the projection does not result in what you want from another view, that really means that the surface is just not shaped in such a way to make that possible. If that's the case you would need to reconstruct the surface to be better suited for what you want to make.

If I could see the model or maybe know more information about the final end result you're trying to build I might be able to give better advice.

- Michael

Hi Michael,

Here is basically the shape I want to build, I made it quickly to illustrate the main problem I have. The bulge on the back and on the side are just here to say that it is not a primary shape and you can't take a sphere and deform it, maybe you can/should?

So my problem is about the cut in front. When I follow the side and trim on my main shape, the front will not follow.
I'm pretty sure that is because of my main shape, and that's the core of my issue, how do you build your main shape to be sure it will fit all your cut in any views. And do you have to tackle this problem like this.
An other thing would be to trace the outline of the shape and build my surface but with that many curve it will produce bulge and imprecise surface.

Sorry for all the newbish question, I still have a lot of homework to do :)

Hi David,

> I'm pretty sure that is because of my main shape, and that's the core of my issue, how
> do you build your main shape to be sure it will fit all your cut in any views.

So I guess that normally you would just not go about it in this particular way of trying to control a cut profile from 2 different directions at the same time...

Focus on one cut direction and on how to form the main shape.


> The bulge on the back and on the side are just here to say that it is not a primary shape
> and you can't take a sphere and deform it, maybe you can/should?

It's maybe possible to deform a sphere but it's hard to get very localized features that way. It looks to me like you've still got a primary shape under that outline, notice how there is basically a pattern that starts at the base and continues above the bumps, here I've traced it with red:




Try to ignore the localized bumps and just work on the non-bumped underlying full form. Try to build a base shape that matches that outline first before starting to get into cuts.

- Michael

Hi Michael,
A quick post to show you what I meant by the cut not having the expected result on each view.


Here I draw my curve from the front and trim on my shape. The cut is as expected on the front but it doesn't match on the side.








Now I made the cut on the side, and the result doesn't match the front =)






I guess it is normal and I have to draw the cut in both view.
But If I move the curve to meet both view we can see that it can't match the shape I built.
So I'm clueless :)