Last year I wrote The Basics Of Matte Painting where I broke down the process of modern matte painting in a way that is perfect for beginners to understand. At the end of the article are the assets I used to create the artwork so you can download them and try recreating what I made. If you haven't read the article, I strongly recommend you do so first and come back to this article afterward!
This article is part 2 of the series, where we will break down the process of matching the perspectives of multiple images. It's easier than you might think, so let's get going!
As usual, let's start with a bit of a theoretical overview. When we talk about "Perspective" in Matte Painting, we're talking about the direction in which the elements of the images get smaller. These are also called Vanishing points.
Most photography will have between 1 and 3 vanishing points. Let's take a look at the image below and consider it's various vanishing points.
"You don't need to understand the theory to be able to put it into practice."
The parallel lines in the image above are converging in 3 different directions; left, right and up. There is such a thing as 4 point perspective but as matte painters we're usually having to work with 1 to 2, and sometimes 3-point perspective.
To help illustrate what 2 and 1 point perspective would look like using the image above, I have distorted the image in the animation below.
Watch the animation a few times through and analyze it until you understand the 3 Vanishing points!
Before we continue, I want to make it clear that you don't have to completely understand what's outlined above. You don't need to understand the theory and fundamentals to be able to put it into practice!
"Keep your Horizon lines all in the same spot and your image will look much more photoreal"
Now that you're aware of all the types of perspectives, let's push that aside and just think of once perspective line, the most important perspective; The Horizon line.
When using Photography for matte painting or concept art, the most important thing to remember around perspective is where your Horizon line is. And here's the trick; if you keep your Horizon lines all in the same spot, your image will look much more photoreal!
Let's take these two images as an example. At first glance they don't look like they could match because one is an aerial shot from above the city and the other is at ground level. Their horizon lines are different.
However, if we simply respect these horizon lines when combining the images, we can actually achieve a pretty believable result!
Because these two photo's are so different, we're going to be pretty limited in how much we can change the positioning. If we move the background up too much it'll quickly start to look strange and if we move the image down we'll lose most of the content. This is why you want to find images with similar perspectives when you start working, it'll give you much more flexibility to move it around.
A More Complex Example
Lets' look at another, more complex, example now that you understand the basic principle.
We'll be recreating the image below using just 3 images and you can download the assets at the end of this article to try yourself. if you do try it, I'd love to see your result of the practice in our discord server!
As you can see below, each image has a different perspective, but we'll be able to blend them all together just fine.
"Knowing how far you can 'push the perspective' will come with time"
Your ability to tell which images will work together and which won't is something that will come to you with experience because it's not just a matter of whether their perspectives match, you also have to consider scale, content, light direction, composition and other things.
If we apply the previous steps and follow the Horizon line exactly, we don’t' get a very usable result. The background mountains end up being too low and we don't see any. This is where your experience and critical eye comes in; knowing how far you can "push the perspective" is something which comes with time, but as a general starting point, think 10-20%.
Bending the rule
So let's lift the background mountains to a good spot. Generally you can do this by moving the layer up in your canvas until it looks strange. Once it looks strange to you, you know you've gone too far (probably much too far). Play around with the layers a little and you'll start to notice where things "break".
For this example, we know the original the forest reference image had a big mountain range in the background, so I've decided to match that roughly as it's plausible that our new mountains will fit nicely.
Be aware, I've moved this layer much more than you will typically get away with. That's because when working with natural or organic images we can usually get away with more misalignment. Conversly, architectural images and anything with clear, rigid lines, will not be as flexible.
Dealing with Scale
Our image is looking pretty good already but the sky is pretty boring, so lets' grab the sky image from our reference set and place that into the scene.
The challenge with this sky image that it is a much wider aspect ratio to the rest of our image. So what we need to do is first line up the horizon and then scale the layer up while using the translation anchor point.
The Anchor point is turned off by default in photoshop, so when you activate free transform (CTRL+T) you'll be able to check the box (above) to turn it on.
Now, position the anchor point somewhere along the horizon line and then hold Alt (or Alt+Shift depending on if you have customized your Photoshop scaling settings) while you transform scale your layer. You should find the layer scales based on the position of the anchor point.
With this process, you can now increase the scale of the layer until the content fits behind the mountains.
When you do this, make sure to pay attention to the overall size of the objects in your image when you do this. You can't scale the image so far that the elements aren't the same scale as the rest of your image. It takes a bit of practice and you might often find yourself going through multiple images because they don't quite fit. As always, practice makes perfect!
Now that our layers are matching we can continue with the matching the grades, working on integrations and other parts of the image!
Want an in-depth video explanation?
There's a lot more to this technical and approaching perspective than just what I've outlined here, so I made a video for the MattePaint Academy do go into more detail. This will give you plenty of foundational understanding to jump off from but if you're hungry for more, check out the tutorial below!
As you move forward and practice this technique, I want you to remember one thing:
If the perspective doesn't match using this method, find another image!
As you gain more experience, you'll understand where you're able to break the rules and where you aren't. So to start with, follow these rules and stick to them. If you really like a certain area of an image but it just won't fit nicely using this technique, tough! Find another image to use. Trying to force the image to work will only end up frustrating you and ultimately not looking good anyway.
Download The Assets
If you want to practice this for yourself, you can download the images used in the article here: Download Image Assets