Coding 8, Section 12 – Crowds

For 8^th grade Science/Coding I am doing Pixar in a Box in Khan Academy.  Currently, I am doing the twelfth section in the course, crowds.

The twelfth section in Pixar in a Box has two parts: “Building Crowds” and “Counting Crowds.”

Part One

In this part of Crowds, I learned how artists at Pixar make crowds.  This part was based on Wall-E, a movie that came out in 2008.  If you have never watched Wall-E, it is about “a machine responsible for cleaning a waste-covered Earth meets another robot and falls in love with her. Together, they set out on a journey that will alter the fate of mankind.”

In the movie there are multiple scenes where there are crowds of robots.  For the animators, animating each and every individual robot will be tiring and tedious.  So the artists have to make multiple different robots, but make it easy for the animators.

This is where combinations come in handy.  If you have not learned about combinations in math yet, it is exactly what it sounds like.  It is combinations, in this case, of heads, bodies, and arms.  For example, if you have two heads and three bodies, you can make six different unique robots (2 x 6).

In this part I made different robots with combinations.  Here are some pictures of what I did:

Part Two

Part two, is all about the math behind combinations.  In the first exercise I learned a formula to find possible robot combinations for a robot with two heads, one body, and one set of arms.

R stands for the number of robots you can make.

B stands for the number of bodies you can use.

A stands for the number of arms you can use.

H stands for the number of heads you can use.

r = h * (h – 1) * b * a

In the second exercise I learned how many possible combinations there can be for a snake.

I also learned a new formula, the binomial coeffient. 

Say that you want a cast of 3 robots, and you have 6 different robots to pick from. 

You would write 6 * 5* 4/ 3! or 6 * 5 *4/ 3 * 2 * 1

The exclamation mark after 3 is known as a factorial (in case you did not know). 

Another way to write this is 6!/3!

That is known as the binomial coefficient, which can also be written like this:

n stands for the number of actors, in this case robots you can choose from.

k stands for the size of the cast, which is 3 in my example.

That is all for this section!  My next essay will be about Section 13 of Pixar in a Box on Khan Academy, Sets and Staging.  Thanks for reading!