Hey guys!!! Guess who. Me.
I thought it would be cool this week to break down the process of UV mapping. We’re going to be projecting images onto a set with protruding set pieces and angles, so trying to get clean shapes mapped onto it will be a challenge. Theo, one of our amazing artists and 2d animation expert and general life guru breaks down the process below.
When you want to “unwrap” something, you’re essentially flattening it into an image that you can paint on. Think of flattening a cardboard box, painting on it, and then building it back into a 3D box. The flat image you create in this process is called a “UV map”. The UV map can be laid out in multiple ways, and the way it’s laid out or flattened has a huge impact on the ease of painting on it without getting “seams” or visible distortion.
Ya with me so far? Good because it’s about to get more complicated!
Since we’re projecting onto a stage, we’re going to have to consider the perspective of the audience as well. Where they’re sitting in the theater will affect how they’re going to view the projection. The above examples are simple and straightforward; map a straight line directly onto a cube, in line with the cube faces. But what if we’re looking at the cube sitting far back and off to the side in a theater? And what if we want to map a straight line across the cube diagonally, cutting across its faces?
Now, what if we want to project something more complicated than just a line? Because lines are great, but we’re gonna need a bit more complexity than that. Below are a couple examples of how we might project circles onto a cube. As you can see, we’re inevitably going to have to fight distortion by accounting for it in the UV map (in the first image). If we use a perfect circle on the UV map (the second image), it will get distorted in the projection.
So cubes are great, but unfortunately the set isn’t a cube. Bummer, right? It has props and angles and protruding shapes and all that fun stuff. Below is a super simple mockup of the set we’ll be working with. The UV map is on the left, and mapping a straight line across it isn’t too complicated! But straight lines are for squares. Ha.
Here’s another mockup of the set projection, this time with the aim of projecting a circle. Oof.
Looks like so much fun right?! Well if you think that’s fun, also remember that we’re trying to map ANIMATION onto the set. Meaning if we want to map a circle onto the set in MOTION, each frame of motion will have to be cut up and mapped onto the UV map so it corresponds to the correct location on the set once it’s projected.
It would be humanly impossible to do that in the amount of time we have, and might drive everyone insane. Luckily there are some After Effects tools that can help the process along, and Theo has been doing some research into what will work best for us!
We’ve got a rough 3D model of the set built, and unwrapped it so we have a rough starting UV map. Hooray!
Now all that’s left is for us to see what we can do with this! Wish us luck and see ya next week, ya squares. Stay cubular.