Water Drop and Flour Sack

Transcription

In the long awaited Part 2 of our Introduction to Flipbook
animation tutorial series, Andre Quijano takes us through
the classic Water Drop and Flour Sack Exercises.
Feel free to start from scratch or open one of the
accompanying demo files.
Example1 Example2 Example3 Example4
INTRODUCTION: ACTION AND REACTION
In this tutorial, we are going to learn how to make drop animations with a water droplet
and a flour sack. This will help us understand the fundamentals of Action and Reaction
in animation, which is the practice of breaking down the actions and reactions of any
given object.
It sounds complicated, but this practice helps map out which parts are in motion. It will
also allow for simple step-by-step animations without the need to worry about the
project as a whole single animation.
Now, a water drop sounds simple. That’s because it is! The whole process can be broken
down into three main parts:
1) Water forms on the top. (1-3)
2) Water drop falls from the top to bottom. (4-5)
3) Water drop splashes on surface. (6-9)
Breaking down your animation is helpful so you don’t get lost or feel overwhelmed
animating something that is both complex and time consuming. We want to make it
short, simple, and to the point.
Example files have been provided for each exercise on page 1, and will be linked again
in each section, as we go.
EXERCISE #1: THE WATER DROP
We will start by creating our file with the settings below:
Presets set to NTSC (780x480), Framerate to 12fps and 15 frames.
To begin, we’ll establish a blue line as the ground plane (body of water in this case)
where our water drop is going to land. From there we can draw in our keyframes for all
three of our parts.
For the first part we need to take notice of the size of the drop and then think about
how far it will stretch and when it will detach itself. If you aren’t sure, don’t fret! Take a
look for examples on the internet or look at your kitchen sink tap.
Observation is vital to animators.
In the second section, when our droplet breaks away from the source you need to realize that it will hang suspended for a short moment then drop and gain speed as it falls.
Also remember that water droplets aren’t tear shaped but spherical.
And for the final stage: The splash. A small wave is being pushed from the drop, heading
upwards and then diminishing in size. The initial splash should be quick and fast and
then the expansion of the small wave is where you’ll animate the most.
Once you have finished, just watch the animation carefully and adjust the timing in any
areas that look off. Remember the hotkeys to help cycle through the animation.

EXERCISE #2: THE FLOUR SACK
The next exercise will focus on a more solid object, the flour sack. The flour sack is a
great example to help us understand weight and its distribution through collision, as
shown below.
Give yourself some time and practice sketching out the flour sack so you can get used to
animating it.
This drop animation will see the flour
sack falling onto a ledge by landing just
off center. There it will sit for a moment
and then fall off.
If you were to break this down like earlier
the process would be:
1) Flour sack falls onto ledge
2) Flour sack’s weight shifts to the left
3) Flour sack falls off the ledge to the
ground
Let’s bring up a new file with the same settings:
Presets set to NTSC (780x480), Framerate to 12fps and 15 frames.
And on our background we will set up our scene as shown.
A helpful hint is the
following keyboard
shortcut that will help
you to cycle through
your animation at your
own pace and also lay
down animation thanks
to the auto-keyframe
feature:
Step one is the sack falling from off screen. This requires some thought as to how the
weight is going to be distributed once the sack lands on the ledge. Also, since the weight
is a powder, it will shift slowly and land at full force on impact, no bounce.
The second part of our animation is the contents of our sack shifting from the right side
to the left, the process is at first slow but gradually builds until our sack falls from the
ledge. This section of your animation will contain the most frames.
The third part of our animation is the secondary fall resulting from the shifting of the
sack’s contents. Once again, the bag will hit the ground and will absorb the impact like
it did on the initial point of contact.
With all three parts created, test out your animation by playing it back. Make sure it all
looks and feels right, fix your timing and clean up some frames and pat yourself on the
back.
ADDITIONAL CHALLENGES
To expand on these lessons, try making a number of drops fall in succession or at the
same time. What if a stream of water from a tap was to be turned on for a brief
moment? Or change your point of view, and animate a tap from above, 3/4 view, etc.
As for the flour sack, you could drop it at different angles or fill the bag with different
amounts of weight. What if the sack was full and then dropped onto the ledge. You
could even fill the bag with different materials like water, rocks, or jelly beans!
Stay tuned for more Flipbook tutorials by Andre Quijano!