
The building that I am creating is 18 meters long in real life…
If TheoHumans are 3 pixels tall which represent 2 meters in real life, you can calculate the number of pixels needed for 18 meters by setting up a proportion.
Let's call the number of pixels needed for 18 meters "S".
Given the ratio 3 pixels : 2 meters, you can set up the proportion:
(3 pixels / 2 meters) * 18 meters = 27
S = 27 pixels
So, you would need 27 pixels to represent a building that is 18 meters long in real life.