Modulo scalar

The Modulo scalar node is a function which does modulo division, also known as remainder division. The calculation it does is very simple and looks like this :

 

Input modulo Input 2

 

The output is the remainder of Input divided by Input 2. For example :

 

5 modulo 4 = 1

 

because the remainder of 5 divided by 4 is 1. As another example :

 

5 modulo 5 = 0

 

because 5 divided by 5 has no remainder. Similarly :

 

6 modulo 3 = 0

 

because 6 divided by 3 has no remainder.

 

One of the situations that modulo division is most useful in is for making repeating patterns. Imagine that you wanted to divide the X axis into blocks 5 units long. You would set up a Modulo scalar node so that the Input was the X position and Input 2 was a Constant scalar node with a value of 5. This will output values which look like this :

 

X value:   0   1   2   3   4   5   6   7   8   9 10 11 12 13 14 15 16 17 18 19 20

Output :   0   1   2   3   4   0   1   2   3   4   0   1   2   3   4   0   1   2   3   4   0

 

As you can see you now get a repeating series of numbers from the output. Note that for this to work you need to make the Input value the varying number (in this case the X axis position) and the Input 2 value the constant value you are comparing with (5 in this case). If you did it the other way around you would get a output like this :

 

X value:   0   1   2   3   4   5   6   7   8   9 10 11 12 13 14 15 16 17 18 19 20

Output :   0   0   1   2   1   0   5   5   5   5   5   5   5   5   5   5   5   5   5   5   5

 

As you can see this does not give the same repeating sequence of numbers.

 

Let's go back to the original example. Imagine you wanted to make every place you get a zero from output as a white dot, and every place you got a number greater than zero as a black dot. You could make a pattern like this (where "o" is a white dot and "m" is a black dot) :

 

X value:   0   1   2   3   4   5   6   7   8   9 10 11 12 13 14 15 16 17 18 19 20

Output :   0   1   2   3   4   0   1   2   3   4   0   1   2   3   4   0   1   2   3   4   0

Pattern:   o   m   m   m   m   o   m   m   m   m   o   m   m   m   m   o   m   m   m   m   o

 

That is a pretty simplistic example, but hopefully you see what is meant. Using modulo division is the basis for creating repeating patterns.