Problems with the ROTATE POINT TOOL

[negroclarito]

Hi everyone,
I have a problem when I animate with the ROTATE POINT TOOL. The problem is that when I rotate one shape, the program also scale that shape.
Also when I rotate some irregular shape, the program change the center point all the time.
Is this an error or is it normal?
How can I fix it?

Thank you

[slowtiger]

This is normal behaviour. If you want to retain shape size and position of pivot point, rotate the layer, or bind the shape to a bone and rotate that.

[2ner]

This is very strange. When I rotate the points of an irregular shape clockwise by small increments, it's pivot position rotates in a non-circular, but roughly counter-clockwise direction.

[slowtiger]

Please understand how this tool works. It is meant to easily transform a bunch of points, but not meant for doing an exact rotation. It only transforms each point's position separately, and when you animate this, in a straight line. The "center" of course changes because it is just the center of the bounding box around all selected points. The center's position is not stored in any way.

If you want to rotate a bunch of points around a fixed center, you need to tell AS what you want, by a) binding all these points to a bone or b) have all these points in a separate layer, adjust the point of origin, and rotate the layer.

[2ner]

Ah yes, the old bounding box. Well, that makes perfect sense then. Thanks Slowtiger.

[negroclarito]

Can you believe it? I've been using AS many years and I've never noticed this.
I know the methods you mencion for rotating, but I never realized about the resizing to rotate a shape with this tool.

Thank you slowtiger for your prompt reply and congratulations to the AS team because the 9 version is the best ever.

[TheMinahBird]

Say I wanted to keep some shapes on 1 layer and just rotate one a certain way? I guess I'd have to add it to another layer huh? :/

[hayasidist]

does it have to be rotate point to rotate them? IOW could you bind the points to a bone and rotate that?

But if it does have to be point motion you can rotate in (say) 30 degree steps - and that will stop a lot of scaling; and/or you can rotate in up to 90 degree steps using Bezier interpolation and then tweak the Bezier handles in motion graph to give you a near enough circular path.

[TheMinahBird]

Yeah it has to be, the way I have the rig set up, and yeah I did just what you said and got the effect! Thanks bud!

[Phazor]

Do you think someone Can create a rotate points tool that does not have this scaling issue, or a rotate shapes tool? For me, none of the solutions To rotate the layer, Use bones, Or rotate in increments would really be the ideal option Because I'm trying to create a complex hand rig that rotates That has a lot of switch layers, so I had to place The finger and its three joints within one layer so that I don't have too many layers. This prevents me from Using the rotate layer because it only rotates one joint And I would still have the problems for the other two joints. Creating incremental key frames to prevent scaling Would have to be done for each finger For every hand in the switch layer Incrementally, Which would take up too much computer resources. I can't use bones because I want this rake to be backwards compatible to earlier versions of Moho before The Vitruvian bones feature, Plus I would also have to create a bunch of bone layers, which would also take up resources. I absolutely need a rotate points tool that doesn't have a scaling issue.

Can someone help?

[Greenlaw]

Hi,

I'm not sure what's meant by this. I rotate point selections all the time with no scaling issues.

Can someone post a video example to show what's happening?

ATM, I'm wondering if the tool is not being used correctly. That, or I'm completely misinterpreting the problem's description.

[hayasidist]

it's because spatial interpolation is linear -- draw a square; select all the points; move down the timeline; activate the point translate tool and type "90" in the angle field to animate it -- the points take the straight line from origin to destination. It's even more extreme if you type 180 in the angle field.

Ideally, both spatial and temporal interp controls would be nice but ...

[Greenlaw]

Oh, shoot...ok, I did misunderstand. I thought this referred to editing points with Transform Points, not animating points on the timeline. Thanks for clarifying this for me, Paul!

Anyway, yes, that's normal and expected behavior for animation...as SlowTiger and Hayasidist said, there are no motion paths for points, so the animation will be linear.

For animation, the two proper and easiest way to deal with this situation are:

1. Use Bind Points to bind the selection to a bone and rotate the bone for animation.

Or

2. Cut and paste the point selection to its own layer and rotate the layer for animation. (I guess you could also use Bind Layer to bind the layer to a bone and rotate the bone. So, actually, 2-1/2 ways.)

While possible to directly animate the points using Transform Ponts, you'll need to do it in stages. I don't recommend this approach because it's too much trouble, and it's not going to look as good as doing it the ways I just described. Methods 1 & 2 only take a few seconds to setup, and they animate perfectly.

Are you trying to do this for hybrid Point Animation + FBF setup in Moho? I still don't recommend rotating the points with Transform Points. If the rotation animation needs to match FBF animation, I would just animate the points as FBF to match the other FBF layer, and not try to interpolate them over time. You can use the Transform Points tool in a regular FBF sequence and it should be fine.

[Rai López]

Well, we indeed have some kind of spatial interpolation control by using bezier type of keyframes for point translation, I'm not saying it'd be practical for solving complex situations (and I doubt a scripting solution would be feasible?), but there it is as a curiosity. I've used it for simple things or Smart Bones, tho...

E.g. a quick (by approximation) "two-keyframe without scaling rotating square" animation:



And the Moho file https://www.dropbox.com/scl/fi/efw0b36d ... mqvuj&dl=1 ...Regards.

[hayasidist]

Well, we indeed have some kind of spatial interpolation control by using bezier type of keyframes for point translation, I'm not saying it'd be practical for solving complex situations (and I doubt a scripting solution would be feasible?) ...

Wes (and I) have done various experiments with bezier keyframes over the years -- the biggest pain with tweaking Bezier keys in the timeline is having to set them one at a time -- this is Wes's script to ease that pain: viewtopic.php?t=32570