Original subtitles

There are several ways in which we can use a Math node get results derived from a comparison

of two values.

These operations can be found in the Comparison category.

Let's take a look at some of them.

The most basic thing we can do is just see which of the two inputs is the greatest.

For this we can use the Greater Than, and Less Than operations.

The Greater Than operation tells us if the first input is greater than the threshold

set in the second input.

Despite the different input names, the two input sockets are functionally identical,

and there is nothing special about the threshold field.

All the node does is check if the first input is greater than the second.

The output of this comparison can either be true or false, but this gets encoded in a

numeric value, with one assigned to true, and zero assigned to false.

This means that given an input to the value field, and a threshold, whenever the value

is greater than the threshold, we get one, and whenever the value is not greater, we

get zero.

And again, there is nothing special about the threshold field, so it doesn't have to

be a constant value, we can feed whatever we want in there, and for each point the two

inputs will be compared.

This was the Greater Than operation, now, the Less Than operation is exactly the same,

except that the output is reversed, giving a result of one wherever the value is less

than the threshold, and zero otherwise.

The Minimum and Maximum operations, also compare two values to see which one is greater.

The Minimum operation checks which value is the smallest, but instead of giving a binary

true or false output, it actually outputs the smallest input value itself.

So whenever you feed two values into this function, you just get the smallest one as

output.

The Maximum operation follows the same principle, except that it returns the greatest of the

two values.

The Minimum and Maximum operations also have smooth variants, which use fancy maths to

make the transition between the two values smooth.

These operations take a third input called distance, which determines the amount of smoothing.

This smoothing doesn't work like a blur, as we can't access neighboring values.

Rather, it uses a clever function which starts taking effect whenever the two input values

are closer to each other than the distance parameter, and gradually offsets the output

proportionally to how close the two inputs are to each other.