Once I rotate an object I can only scale and rotate in world coordinates.
I need to be able to rotate a cube for example along its own axis even after its been rotated.
Is there a way to have local coordinates available when rotating and scaling?
Seems simple and obvious enough....methinks Im missing something?
Thank Kindly

Hi Stav, MoI does not maintain a separate local coordinate system for every individual object.

But there are various ways to get what you need - one method is to use View > CPlane to set the construction plane, that will then alter the primary coordinate system that's used for picking points and drawing things. After you place the CPlane you can then use Transform > Rotate and it will rotate in that particular plane.

You can also use the Transform > Rotate > Rotate Axis command to rotate around any specific axis you want by picking the 2 points for the axis line. When you're in the 3D view you can then snap on to any face for picking the rotation axis line, that works like this:




Similarly for the Transform > Scale commands you specifically pick the origin of the scale so snap that on to the location you want to scale around.

You'll want to have "Object Snap" and "Straight Snap" both enabled on the bottom toolbar when doing these transforms so that you'll get the kind of snaps that you see in the screencap above.

- Michael

Hi Michael
Thanks for the speedy response!
I figured that was the solution....a few more clicks than I expected though coming from polygon softwaer :)
Im curious why you haven't implemented a simple gimble of sorts?
Considering the simplicity and elegance of everything else.
I imagine such simple manipulations are amongst the most common.
I also often find myself wanting to grab the centre of an object
and wishing there was a visible centre point when selected.

While Im at it please let me ask one more thing.....
When I am editing points on a curve I often select objects around the points by accident....can be very frustrating.
Is there a way to have moi ignore other object selection while I am i points edit mode?

Thanks kindly!

Stav

I think a gimble or transform widget would be quite useful too especially since I find myself often manipulating points on surfaces and curves and it would be nice to have something larger to grab onto than just a point (especially when you have a lot of them in your scene).

I find the edit frame one of MoI's really great features, but once you rotate the object the edit frame does not align with it anymore it stays in world space instead of local coordinate system.

Anyway some more suggestions for the v3 or 4 wish list.

Hi Stav,

> Im curious why you haven't implemented a simple gimble of sorts?

Usually with CAD software things are more focused on precise editing. That gimble type method that you're asking about tends to be inaccurate.

With MoI it's just more usual to draw what you need in place and have it directly constructed in position rather than starting with some other object and flipping it around.


> I also often find myself wanting to grab the centre of an object
> and wishing there was a visible centre point when selected.

That's something that I might add in the future, but again often times the center of an object's bounding box is a kind of arbitrary point as compared to things like ends and specific snap locations.

In MoI v3 when you use the Transform > Move command there is a button that shows up in the command options that you can press to use the bounding box center as the base point of the move, that may possibly do what you need here.


> When I am editing points on a curve I often select objects around the points by
> accident....can be very frustrating.
> Is there a way to have moi ignore other object selection while I am i points edit mode?

You can lock objects (Edit > Lock or hold down Ctrl and click on the left column in the scene browser) and that will prevent them from being selected.

But a lot of the things you are referring to here lead me to think that you're kind of trying to use polygon modeling techniques inside of MoI. That can be frustrating in general because MoI is not really designed with that kind of workflow in mind, you should normally be doing most of your control point editing on 2D curves rather than on 3D objects, and doing things like generating objects in place directly from profile curves rather than trying to squish some other object around.

Check out here for some links to discussions and general tips for people who are coming from a sub-d / poly modeling background:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4865.2


- Michael

All the CAD programs I have used have gimbles for transform, scale and rotate.

Some examples that I have used is Autocad, Inventor and ViaCAD so it is not a tool that is something only polygon modellers use.
It is usually an option that the user can turn on or off as required, depending on what they are doing.

There are plenty of things you need to model and transform that does not require precision, only a good eye and transform gimble. To some extent you have this with edit frames but they are not useful for moving objects and they aren't any good for scaling once you have rotated the object a little bit as they only work on the bounds of the object.

Anyway it is something to consider for future versions of MoI.

Hi Kevin, it is something that I'd like to add in the future, certainly it could be useful in various situations where you just want to eyeball things. Basically that kind of operation just hasn't been as high of a priority as other stuff yet.

I decided to put more emphasis instead on the edit frame, since that lines up well with 2D editing and drawing and editing 2D curves has been more of the focus area in MoI so far.

One thing that's nice about the edit frame instead of a central manipulator is that you can do some kinds of basic accurate scaling with the edit frame that aren't normally possible with a center type manipulator, like for example here I scale a shape using the edit frame and there is a snap available to make the object scaled by the exact amount to fit between 2 other objects:



Because the edit frame works by operating on the object boundary it enables accurate scaling of areas of the object that are on that boundary line.

Then on top of that the other really big plus about the edit frame is that it's much lower profile than a manipulator widget, instead of taking up a bunch of screen real estate right in the center of things, it instead goes totally around the outside of the current selection and is also sparser as well. That helps make it feasible to keep on all the time rather than having to constantly turn it on and off.

Anyway, those are some of the reasons why I decided to do the edit frame initially instead of one of those other central manipulator types. The other kinds of manipulators do have benefits in other kinds of situations so I think it would make sense to eventually have them as well, I just viewed it as a somewhat lower priority item.

I also have some general concept about maybe having a 3D edit frame that also goes around the outside of the object at corners rather than a center one, but I haven't had time yet to experiment with that. A 3D corner frame may possibly give some of the type of exact scaling functions like I show above with the 2D frame and maybe would have a little bit of the "stay out of the way" properties as well (but maybe not too...).

It could be possible that eventually there might be a 3D frame and also a center type manipulator as well, but I'd probably like to try and see if that can be avoided first.

In the meantime the transform tools under the Transform palette can do a lot of things already like rotate a box around one of its faces as shown previously. Since there is a set of flexible tools for doing those kinds of things that has also made it not a big priority to do a 3D manipulator yet as well.

- Michael

Michael,

Don't get me wrong, I'm a big fan of the edit frame but it does have its limitations.

I am often using them to scale cross sections for wings and fuselage for lofting purposes except I am scaling them in the end on direction (trying to scale the red cross sections in the image below to match the wing thickness).

Once I rotate one of those cross sections (eg to match the angle of the wing), I can no longer use the edit frame because it squashes the profile out of shape because the edit frame doesn't work on local coordinates (see attached image).

Your feature request is a million miles long, so I only put it out there that edit frames working on local coordinates of the object would be very useful.

Also having a gimble option that you can turn on and off that works with points and objects would and also works for local coordinates would be very useful, especially for those people doing more organic, freeform type modelling that doesn't require absolute precision.

Why not use Transform / Orient / Line-Line ?
That works on any orientation!

Frenchy,

I start off with thickest wing cross section and copy it multiple times along the length of the wing. I then have to scale each of those cross sections down in size to match the front profile of the wing.

I use scale 1D for this, but if local coordinates worked with edit frame it would be even easier.

This is just an example to make a point about how local coordinates and widgets would be useful to have to speed up the workflow. I can easily find other workarounds within Moi which is what I am currently doing, they are just a little slower.

And use the View/CPlane temporary don't help ?

Hi Kevin,

> Once I rotate one of those cross sections (eg to match the angle of the wing), I can no
> longer use the edit frame because it squashes the profile out of shape because the edit
> frame doesn't work on local coordinates (see attached image).

I'm not sure if I'm understanding your specific example there - are you in the Top view there and working on profiles which are vertical planar curves?

How does the edit frame end up squashing your profile in that particular case? If you're in the Top view if you either rotate or scale the shape it should still remain a planar vertically oriented curve, no matter what bounding frame it presents...

- Michael

Michael

I am in front view.
Hopefully this image is clearer than my roughly drawn one.

The edit frame when squashing the cross sections in front view aligns with World Coordinate System rather a local Coordinate system.

@Frenchy

Yes aligning the cplane is another way in MoI.


I think both of you are missing the point. There are otherways you can achieve the same thing in MoI and most software for that matter but having a widget or edit frame that you scale, rotate or move in the Local Coordinate system of the object is quicker and easier than all the otherways which is the reason most 3D software have such an option.

Is it something similar to this Kevin? http://screencast.com/t/Pz7vK9P0Emk

Clicking the right mouse button on the rotation handle (edit frame turns green) causes that particular software to enter the kind of mode I think you're describing.



Martin.

I must miss something :)
When you rotate something with the Edit Frame it's from the center of rotation of the object so local one for the selected object?
Or any point of the 3D space if you move the little "star"

Can you put an image before / after of what that don't work ? or a little file 3Dm of the result wished

Here in the 3D view (does the circular dashed points + star = a gimble ? )

Hi Kevin,

> I am in front view.
> Hopefully this image is clearer than my roughly drawn one.
>
> The edit frame when squashing the cross sections in front view aligns with
> World Coordinate System rather a local Coordinate system.

If you use the edit frame to do a uniform scale up or down it's not really particularly relevant which specific orientation the edit frame has right then, it will do a uniform scale from the bounding box center and that should not do anything that I'd term "squashing" to the curve.

It would only get skewed (in rotation, which you can then adjust by grabbing the rotation handle) if you track along one of the x or y directions of the edit frame which does a one-directional scale instead of a uniform scale. But you can solve this by just moving your mouse some distance away from those one-directional scale tracking lines and that will then "shake off" the one directional scaling and do uniform scaling instead.

Here's an example - notice how after I "shake off" the one directional tracking that it then does a uniform scale which should not squash your curve at all:




- Michael

"Shake off"......... Learn something new every day!


Grandmaster flash and Mellie Mel would be proud.

Hi Burr, yeah so the way the "shake off" works is if you move your mouse far enough away from either of the X or Y tracking lines, when you move your mouse back to that original area it won't attempt to track onto those X or Y lines anymore.

That can help you to do some finer tuned uniform scaling with the edit frame, basically turning off the one-directional scaling for just that handle grab.

- Michael

I had seen you mention before about getting "away" from it, but always struggled and resorted to lots of "zooming and panning" to keep in the "diagonal drag"......

It was enlightening to realize it could create that second mode. The temporary turn off. the unform scale only. The bees knees.

Michael,

Thanks for the tip about shake to scale. I just tried it out and it seems to scale the whole object up and down in size rather than in one direction only (along the normal) like SCALE 1D.


When working in 3D just about everything is placed at weird angles so having the ability to align the edit frame with the objects normal would make it more useful if you just need to scale it in one axis.

If we use a cube as an example. I have rotated it in 3D so it is no longer aligned to the XY plane.
In polygon modellers you can then align the scale widget to the normal of the object and can then grab any of the handles to scale the object in 1D along that axis.

The second image shows how MoI works, when you try to scale along any of the axis you distort your cube.

Hopefully this example explains it better ?