pendulum arc

[Thunderdog]

hi all, I've just started to try and learn this program(demo). It has a really nice help file. The thing I can't find, though, is how to rotate an underlying image along a pivot so that I can trace over it in the current frame.
The example would be like doing a pendulum and wanting to keep the measurements exact and the arc perfect. You'd normally just overlay your successive frames over your key on the light box and trace and then reset your images in peg position, right?
So, how do you do this in tvpaint? The only way I can figure - which is quite clumsy- is to either use the cutbrush and set the angles in the brush options or make a rectangle selection and use the transform tool> blue line the temporary drawings and then trace over my needed lines. The reason I call these clumsy is because I can't see how to rotate the cutbrush/transformed tool drawing directly over my needed pivot. I'm trying to use the panto option on the brush but I can't figure out how to get it to work correctly...assuming it can do what I'm asking. The help file was confusing(or i'm easily confused) on the explanation on it.

Is there a way to rotate a temporary instance on a pivot so that you can reference it for your current frame?
Can you check arcs in a more convenient way than making a large circle on a separate layer?

[Elodie]

Hello Thunderdog, Welcome to the TVPaint community =)

To animate a pendulum, i advise you firstly to draw your it on a first image.
Then cut it with the tool Tool : cut brush (on the main panel, looks like a B with a dotted shape around)
After cutting your brush, you will automatically switch to Tool : CustomBrush.
Look at the different options : you will find the option "Handle".
Click to make appear a pop-up menu and choose "Custom".
Define define your pivot point on your custom brush.
Then, frame by frame, rotate your custom brush by hitting [C] on your keyboard. (To keep a good rendering, I advise you to change "Smooth" into "Medium")

Is it okay or would you like to have some screenshots ? =)

[Paul Fierlinger]

If mechanical accuracy isn't a big issue, you might want to take advantage of the LightTable's off pegging feature.

[idragosani]

Is there a way to rotate a temporary instance on a pivot so that you can reference it for your current frame?

Have you looked at the off pegs feature for the light table? That's exactly what it does.

Can you check arcs in a more convenient way than making a large circle on a separate layer?

I've done the pendulum exercise with TVPaint. I did it fairly old school and just drew the arc on a separate layer and marked on the arc where I wanted the starting and ending points, as well as the in-betweens (using ease in and out, of course) -- just a basic timing chart right there. The drawing of the actual pendulum was easy from there, no rotating needed.

[Thunderdog]

Ah! The off-peg feature..Nice. I looked right over that in the help file. Sorry. I don't see how to change the pivot point though...

The handle option is very nice. The light table, if it has the ability to change pivot, would be exactly what I'm looking for. If it doesn't, the handle option on the brush options is a close work around. It looks like I'll have to blue line after stamping and then come back and draw over what I need.

Thanks, Elodie, Paul Fierlinger, and idragosani!

[Paul Fierlinger]

Are you testing with TVP10? Because 10's off pegger does have tilt.

[Thunderdog]

Yes, it has a tilt, but the pivot is in the center of the square. i want to be able to put the pivot where I want.

[idragosani]

I think you can drag the pivot point to wherever you need it and then rotate.

[Paul Fierlinger]

Ah yes; well, that's what I meant by saying 'If mechanical accuracy isn't a big issue'.

[Thunderdog]

idragosani: I see that in the handle option for the custom brush option. I haven't been able to get it to work with LB.

Paul: I figured that's what you probably meant. Bummer..
Elodie provided a great work around though if you need something a little more precise. I'll probably use the light box mostly though because of the speed if I can figure out why my results are so inconsistent.

[Paul Fierlinger]

if I can figure out why my results are so inconsistent.

In which way?

[ZigOtto]

idragosani: I see that in the handle option for the custom brush option. I haven't been able to get it to work with LB.

Handle/Custom/... LMB-Clic&Drag the Pivot point from where it is to where you want,
then, you can store it into the bin tab (to "record" this new pivot's position).

[Thunderdog]

Hmm, ok, it was just a limitation:

I make my first frame and then go to the 2nd frame and then turn on the lightbox. I click the greybox for the out-of-peg feature for the previous frame(first frame) so that I can rotate it for reference for my 2nd frame. The first frame's unaltered lightboxed image disappears. I only have the modified(rotated) version of it

Seems like the workaround is to extend the exposure on the first frame by 1 temporarily.

[Thunderdog]

idragosani: I see that in the handle option for the custom brush option. I haven't been able to get it to work with LB.

Handle/Custom/... LMB-Clic&Drag the Pivot point from where it is to where you want,
then, you can store it into the bin tab (to "record" this new pivot's position).

Thanks. I got that part for the custom brush. The LB doesn't seem to have a handle that can be adjusted.

[ZigOtto]

idragosani: I see that in the handle option for the custom brush option. I haven't been able to get it to work with LB.

Handle/Custom/... LMB-Clic&Drag the Pivot point from where it is to where you want,
then, you can store it into the bin tab (to "record" this new pivot's position).

Thanks. I got that part for the custom brush. The LB doesn't seem to have a handle that can be adjusted.

well, I've apparently missed what's the meaning of "LB" ...?
maybe you are refering to "Light Box", which is called here "LT" (for "Light Table"), ...?

anyway, at your place, I would go an easier way to get this pendulum move : make an anim-template by using the KF,
then, if you want to keep a handdrawn aspect, draw over this template, in a new animlayer.
more detailed procedure :
grab your pendulum (animated part) as custombrush, set the pivot to the top,
in the KeyFramer_FX, set your custombrush as Source, position it on its axe,
set 2 keys in the anim timeline, the first key (bank) rotated say to -15°, the second one to +15°
set the progress profile curve to a "S" shape, select All + Apply .
you will get a very consistent pendulum animation as template,
the arc path and the spacings being auto-generated,

pendulum.gif (82.91 KiB) Viewed 26695 times

of course, you can adjust the bank rotation amplitude and the global timing to fit your wish,
then freehand-draw over like when rotoscoping, (draw one on two only if you are animating in 2's).