# Tweening

Hey all

I just started exploring TBS and after reading quite a few tutorials and seeing the instructional videos I’m still a bit puzzled about tweening.

I’ve seen in tutorials, let’s say the nicely done JK’s one with the fish and the shark, that he tends to draw each frame of the fish animation himself instead of creating the 1st and last frame and then letting TBS tween the in between frames. That seems to me like defeating the main purpose of using an animation program. (Of course he does it for demonstrating purposes, but you see where I’m getting.) So, I would really appreciate a simple, step by step demonstration of the tweening concept like so:

I have a pendulum (a string and a ball for simplicity); I draw the 1st frame (ball on the left of the screen, top of string on center, end of string on the left with the ball), indermediate frame (string and ball at thew center) and last frame (ball on the right of the screen, top of string still on center, end of string on right with the ball). How can I make TBS draw the in between frames?

Thanks in advance to anyone interested in shedding some light on this one for me.

lol, exactly what I wanted. Although it had no sound, I think I got the gist of it. thx

One more quickie about tweeneing. I understand how cut-out animation works, but I want to make a whole character move (i.e., one that is not made up of various body segments.)

I have two drawings of a man (say, the classic stick figure, drawn as a whole). I put the first one of the 1st frame (feets closed) and the second one (left foot forward) at the 10th frame. How can I make TBS draw the in between frames? Or, can I someway transform the 1st drawing at the 10th frame and have TBS draw the in between frames? (and not use the 2nd drawing at all.)

In the pendulum example we had simple rotation; but here I want the actual leg, hands, etc to do more complicated movements.

The way I currently do it, I “extend exposure” the 1st drawing for 10 frames and at the 10th I try to “Transform” it with the Sceneplanning tool; but there are just not enough grip points to make the limbs go the way I want. The “Select” tool works (the drawing select, not the sceneplanning one) because it gives me enough grip points, but it also alters the 1st drawing.

In short, is there a way to morph the first drawing to the second, or to alter the 1st drawing at the 10th frame, and have TBS draw the inbetween frames?

I hope that was, somewhat, clear… :

Well, first you have to build your “rig” - creating a logical hierarchy…

Please have a look at JK’s excellent articles:

or Toon Boom’s:
http://www.toonboom.com/products/toonBoomStudio/eLearning/tipsTricks/convertCutOut/

http://www.toonboom.com/products/toonBoomStudio/eLearning/tutorials/cutOut/

or this video demonstration:
http://web.mac.com/nolan.scott/Gallery/Draw_a_Chicken.html

Cheers
Nolan

I suspect from your question that you are unclear on how tweening is actually implemented. Essentially tweening is the calculation of inbetween change values between two parameter driven values (numerical values). The number of incremental change values is based on the number of inbetween frames and the mathematical function that describes the spacing between each change frame. Closer spacing means small change, larger spacing means greater change. The operative part of this process is of course parameter driven values (numbers). An example of a parameter driven value is a scale multiplier or a rotational position value or a grid location offset value. So, for example, if you have an object and you apply a scale multiplier to that object and you separate the keyed values by 8 frames that are equally spaced apart then TBS will calculate the inbetween scale multiplier values for each of the eight inbetween frames as 8 equally space incremental values.

Now if you have a single drawing of a stick figure and you have a second drawing of the exact same stick figure and the two drawings are in different poses separated by some number of frames TBS has no parameter driven values to interpolate (calculate) between two slightly different single drawings. Therefore it can’t tween anything, or morph between the drawings. If you construct the stick figures as a cut-out character and you move the left arm element in a series of keyframes then you have rotational and locational parameters (numbers) that have changed for that object or hierarchy of objects and those can be tweened. Tweening is implemented between keyframe values which are simply numerical values and tweening itself is a series of numerical values that are mathematically calculated by a tweening equation and then those calculated values are applied at specific frames between your keyframe values so that they can modify the display of your visual object.

In order to do morphing or “shape tweening” TBS would have to calculate the variation in each associated vector point between two drawing objects. This is extremely complex and far more mathematically intensive because an object can consist of literally hundreds if not thousands of individual vector points. And two similar objects can easily have different total numbers of vector points depending on how they were drawn, so matching associate points between images is additionally complicated. TBS doesn’t possess that capability. You would have to move up the product ladder to a more expensive and more sophisticated Toon Boom Software product to gain that feature. -JK

Thanks for the answer Nolan. I understant the hierarchy system (I think), but the chicken video was just a more advanced implementation of the same pendulum method from the previous video; i.e., cut-out animation (if I use the term correctly.)

What I’m trying to do is to draw, say, the chicken but as a whole, not break it down to body parts. Then put it in as the first frame, and 20 frames later to put the same chicken but in a different stance (maybe by manipulating its “grip points”) and have TBS draw the in-between animations. Is this possible or do I have to do it like in the video, by breaking it down to limbs and animating them one by one? I guess I’m talking about some kind of “morphing” which I think would be less time consuming.

I guess JK cleared this up. Thanks for the answers guys. I’ll try the cut-out method.

JK, by “moving up the product ladder” what exactly you have in mind? I’m guessing TBSDPro?

TB Animate advertises that it supports morphing as does Digital Pro. I have no experience with either product so I suggest that you use the PLE trial versions or at the very least go on to the other product forums and ask actual users for their comments. Having said that, you need to understand that morphing like tweening is not going to give you the best results. I just recently published a tutorial on Keyframing a Bouncing Ball to demonstrate how to use tweening as a rough starting point and then to manually fine tune the results to achieve a non-tweeny looking animation. You will find this article on the Cartooning in Toon Boom blog. My point being that you may not want to be so quick to abandon basic animation techniques. The computer is an assistant but not a great assistant and you still have to polish the work generated by the computer if you want a decent result. -JK