Skewing a shape

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 From:  mickelsen
4382.1 
This may be a simple one, at least, the example is simple. The overall capability may be more complicated.
I imported this shape into a drawing page but I need to be able to skew the shape so that the straight lines are at right angles to each other, and I need the curves to follow along proportionately. Is there a command that will let me do this?
Thanks,
Mark
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 From:  DannyT (DANTAS)
4382.2 In reply to 4382.1 
Hi Mark,
If you turn on your control points you can drag things around, like I show in the video.

Cheers


~Danny~
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 From:  Michael Gibson
4382.3 In reply to 4382.1 
Hi Mark, like Danny shows you need to turn on control points with Edit > Show pts and then you can manipulate them to make adjustments.

The Transform > Align command can be handy to use for adjusting points to be in a straight vertical or horizontal line:
http://moi3d.com/2.0/docs/moi_command_reference8.htm#align

Also if you want to have a curved piece stay more rigid in shape instead of having it deformed, you can use Edit > Separate to break it into segments, then use a combination of scaling + rotation to reposition it. The Transform > Orient > Line to line command can be useful for doing that since it combines scaling and rotation together with just a couple of picks:
http://moi3d.com/2.0/docs/moi_command_reference8.htm#orientlinetoline

- Michael
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 From:  Mike K4ICY (MAJIKMIKE)
4382.4 
Marc, Michael,

The following steps are more for "skewing" or shearing objects out of perpendicular alignment, but could be used to get close in the opposite manner.
I'm not sure how to figure out what amounts in each step are needed to get an exact shearing angle, but it would be nice to add a handle or Transform tool to do this.
(hint hint)

You start out with your original object:


Rotate using the base line as reference: The accuracy of the Transform > Rotate tool is scary!


2D Scale a bit, either direction:


Rotate back to the origin line:


Scale in directions needed to get it back to relative proportion:



This is how it could be done:



You know, the more I use MoI's transform tools, the more I wish the "drawing" programs had them. ;-)

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 From:  BurrMan
4382.5 In reply to 4382.4 
Make a square plane a bit larger than your shape and trim it with your curves, then turn on cntrl points for the plane. You'll get a 4 point skew grid.
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 From:  Michael Gibson
4382.6 In reply to 4382.5 
Check out here for some illustrations of the method that Burr is describing:

http://moi3d.com/forum/index.php?webtag=MOI&msg=909.5

- Michael
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 From:  Mike K4ICY (MAJIKMIKE)
4382.7 
But in 3D... ;-)

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 From:  Michael Gibson
4382.8 In reply to 4382.7 
Hi Mike - re: 3D shear - I should be able to make a Shear command that will handle doing a shear on a 3D object like that, but it should be a quite unusual circumstance to get an already sheared 3D shape like you show there that needs correction to be straight.

When there is a shear command, it's much more likely something that you would use to introduce shear to an existing straight shape rather than correct a sheared solid. You kind of have to put some effort into making a sheared solid in the first place.

Really to correct a sheared solid like you show there, I'd recommend duplicating the base curves at the bottom (and any other key locations) using copy and paste, and then construct a new solid using extrude/revolve/etc making a straight shape.

- Michael
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 From:  Mike K4ICY (MAJIKMIKE)
4382.9 
Thank you for considering that addition.

Yes, the intentional use of shearing can be quite an esoteric action. But, from experience in the 2D world, those times you want an interesting "slant" on something rears it's ugly head when you least expect it.

In the case of correcting unwanted shear, I deal with that on a constant basis when working with oblique fonts and logotype creation.
The best way I was trained (and the course that makes the most sense) is to first use Skew to get it to something as close to straight as possible, then work on Aligning points and curves.

MoI's on-the-fly construction guides and Alignment functions are crucial for OCD driven designers such as myself. ;-)

Mike
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