Rotate object so edge = horizontal/vertical

[Anonymous]

I have an object that's basically rectangular but in top view, it's rotated away from the world axis in some arbitrary angle - I want to rotate it back so as one of the sides is either aligned with the Y axis, or the X axis.

I know there must be an easy way to do this, but I can't seen to find it anywhere in help or even google.

Other apps makes this so much easier and obvious - Photoshop, Rhino, SketchUp to name a few.  But in max it's buried somewhere, probably under some odd name or I'm just to blind to see it.

I know I can set the pivot to a corner vertex and rotate from there, but there's no way to see when you've rotated it either horizontal or vertical nor can I snap to those orientations.

Can someone please enlighten me on how to do this simple task?

Thanks.

PS: I've tried using the Max protractor to try and measure how far off horizontal the object is, but find it totally confusing and counter to how I am used to working with protractors in the real world (and even other apps).

[-niels-]

I'm not fully sure on what you want, but i hope i'm guessing correctly.

To rotate objects you can change the "reference coordinate system" to suit your need, so maybe that could be an easy option:

There is also the "align" function, with which you can also set orientation:

Does either of those options help?

[shinodem]

I think he asking how to align model if there is wrong system coordinate like from imported model but need to align it to world axes

[Anonymous]

I have same problem. the object already rotated, So how can rotate back exactly to Horizontal or Vertical Direction. This Question is not answered yet. How can you Algin to Vertical an already rotated object ?

[10DSpace]

Hi @Anonymous 

How can you Algin to Vertical an already rotated object ?

Assuming the objects pivot is still centered and aligned properly all you have to do is:

1. activate the Rotate transform

2. Select "world" as the reference coordinate system

3. Right click on the spinners to zero the x,yand z spinners

And the object will be aligned to world axis (see image below)

There is another scenario in which the object's pivot has also become rotated with respect to the object, and for that you just have to first align the object's pivot properly.   There are a variety of ways to approach this depending on the complexity of the object and what part of the object you want to align to the world axis and it is not hard, but it is case specific to a  degree.  But maybe the above is the simple scenario which I think you were asking about. 

[CAMedeck]

Here's the unfailing solution to square an object up to the grid.  Create a box, and enable AUTOGRID.  Draw the box on a flat surface of your object.  This box is now 'rotated' to match that surface.  You can do some copy/paste between the two objects with some possibly minus signs to adjust the source object.  But the easier method is to link the source object to your box, then zero out the rotations of the box.  Everything should be nice and square, and I recommend using Reset XForm utility on the source object to reset the transforms.

[Anonymous]

Hi 10DSpace !

Thank you for the detailed answer.

I understand now and a can align the object to any direction.
That is OK....

When I wish to do symmetry an object what is already rotated I have problem. I can't align to vertical the mirror plane of the symmetry modify. When click to the mirror inside the symmetry the plane is in the same angle than the object. I just right click on the rotate spinner and all coordinates are on "0", also down in the pivot properly the coordinates are on "0"when I try to change the "0" to "90" on X,Y, or Z coordinate the mirror plane is going to any direction but not to horizontal or vertical.

So how can I align the Symmetry's mirror plane ?

[10DSpace]

@Anonymous 

Symmetry is a modifier  and this is a different case than your first question which was how to align an object in world space.  Symmetry is relative to the pivot point of the object.   If you want to change the orientation or position of the Symmetry modifier gizmo you can so by directly manipulating it as you seem to have found out.  But you cannot use the spinners in the transform dialogue to zero out the world orientation of the symmetry modifier (as you have also found out. )    And symmetry is really intended for use in duplicating 1 side of an object like a character so you only have to model 1 side and the other side is automatically updated.

If you want to duplicate a whole object with symmetry in World Space, a much better choice is Mirror (see below).   I think this is what you are trying to do based on your post. 

[CAMedeck]

@10DSpace you are correct, the Mirror Tool is the way to go.  However, I would highly recommend using the Geometry option versus the Transform (radio buttons at the top of the menu).  Transform simply applies a negative scale to the object to get it to mirror, which can cause issues further down the road.  Choosing the Geometry radio button will apply the Mirror modifier instead, but give the same result.

I encourage people to not scale objects at the base level period.  Sub-object, or through a modifier, is fine.  But at the base level, every object should be scaled to 100%.

[10DSpace]

@CAMedeck 

Thanks for the additional info re Geometry vs Transform Radio Button in the Mirror Tool.  I did not realize that selecting Transform  "simply applies a negative scale to the object to get it to mirror".   But I am puzzled because this altered scaling does not show up when selecting the scale transform for the mirrored object.  In other words, the mirrored object (via Transform radio button) shows scaling at 100% in all Reference Coordinate systems.  Can you clarify why?  

I completely agree with your comments about only scaling at the sub-object level.  

[CAMedeck]

Strange, it is working as I explained here.  I am using 3ds Max 2020, and can reproduce this by doing the following.

Create a teapot and click on the Mirror button from the toolbar, which opens a dialog.  Choose Transform at the top, and press OK at the bottom.

One thing to be mindful of, however, is that negative scales can mess with the coordinates displayed at the bottom of the 3ds Max window.  Open the Transform Type-In box to be sure you're seeing the right numbers.  Mine was displaying the same arbitrary values for all 3 transforms along the bottom as I cycled through the tools.  The TTI window was always correct, though.

In previous versions of Max, I had noted that having a negative scale on an object would prevent you from zeroing out the rotation correctly.  The rotational values displayed at any window would become incorrect and arbitrary with negative scale on an object.  Super frustrating!

[10DSpace]

@CAMedeck 

Thanks for the clarification.  I see the negative scaling in the Transform Type-in as you say.  I had been relying on the transform info at bottom which for the primitive I was using yesterday, was showing all (positive) 100%.  Anyway, today it is behaving as you have said.  I am on Max 2020.3 also.  I was able to reset the scaling to 100% with Reset XForm & Collapse, however, so for objects that have been mirrored already and further modeled, presumably Reset XForm/Collapse should set things right?

[Anonymous]

Using the Reset XForm utility is a great way to fix anything that's got weird scaling, regardless if it is negative or not.  Before you collapse, though, keep in mind that any modifiers applied under that XForm modifier are subject to the effect of the scale.  If you use Real World Coordinates in a UVW Map modifier, you'll want to drag that ON TOP of the XForm before collapsing, or be sure to add a new one after the fact.  

[10DSpace]

@CAMedeck 

Thanks for all of the additional info.

[Anonymous · Accepted solution]

10DSpace

Thank your detailed answer

I have found the solution.
So I have rotated object in any direction. Just simply use reset XForm .
Convert the object to editable poly (together with reset XForm)
Than apply the symmetry and the Mirror plane become Vertical to the Absolute World automatically. Very easy.

Thank your answers.

[CAMedeck]

That is also a perfectly reasonable solution.  As mentioned earlier, the Mirror modifier is probably more appropriate here than the Symmetry modifier, unless you plan to have the object intersect itself.  Although in all honesty, I don't know if it makes any difference which you use.  

[Anonymous]

Thx