From the course: After Effects Guru: Integrating Type into Video Volume 2

Creating a water effect with caustics - After Effects Tutorial

From the course: After Effects Guru: Integrating Type into Video Volume 2

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Creating a water effect with caustics

- This displacement map effect that we've used in the previous movie, is a great effect. But if you need to simulate water or liquid inside After Effects, there is a special tool just for that and this the Caustics effect. This one is also a compound effect meaning it create its distortion by using pixels from another layer and it was designed specifically to render water. So let's put it to action and compare the results. So, just as a quick reminder, what we did so far, was to create a displacement source, so I'm just going to double-click on it. This displacement source consist of three effect, the tint level and fast blur, and we are using it in this composition with the displacement map effect and this is to create the illusion that this text is actually lying at the bottom of this pool and the water is refracting and distorting it. But I think that there is a better way to work. Which means that there is another displacement effect inside After Effect, that you should always consider especially when you're trying to create something that needs to reflect water. So I'm going to turn off the visibility for the displacement map just so we can compare the two and I'm also going to fold up this triangle. The effect that I'm looking for is under the simulation category and the name is Caustics. So I'm just going to double-click and apply the Caustics effect. Now Caustics, in case you don't know, is the envelope of light rays reflected or refracted by a curved surface or object. So imagine that you are standing on top of a swimming pool and you are looking down into the water. You can see those sparks of light that are reflecting from the watery surface by the sun. And this is what the effect is trying to achieve. But I really love the definition of the effect itself. So if I'm going to click on the About button, it will tell you that this effect is trying to render water. And this is exactly what we have in this case. So let's try and work with this effect in order to create a better watery surface. So the effect is divided to three main sections. There are a couple of more over here so we can control the lighting and material. We'll get to those in a moment, but for now, we need to define the bottom of the pool. In this case, the bottom of the pool is our text. This is the message and this is already set up for us so we don't need to worry about it. We can actually fold it up. Then we need to define the water and the sky. Now I'm not going to reflect or refract any sky but you can use the effect to do so so in this case, I'm also going to fold up the sky parameters. But we do want to change the water section. So the water surface here, is going to be our displace source and already it looks more promising than the displacement map, but obviously, it is too heavy. So we don't need the surface color. The effect assume that you want the color of the water to be some sort of a blue color and in this case, I don't want it, so I'm just going to change the surface capacity all the way to zero in order to see their result and I'm also going to zoom into this comp so we can get a sense of how it looks on 100% zoom. Then we need to change the wave height and the smoothing and of course, the other parameters if we need to. So let's start with the wave height. I'm going to scroll it down to a very low number. Let's settle with 0.05 and already we can see that it looks much more impressive than the result that we've got from the displacement map effect. And of course, you can check it in motion. So if I'm going to run preview frames, you get a sense of how this looks while it's moving. And it really gave us the sense of water, however, because we are displacing it so much, it's going to be very difficult to read what the message over here is saying. So let's just move it over here so we can get a sense of how the message is appearing and you can control the appearance by setting a higher number for the smoothing. So the higher the number here, the smoother the result will be. So let's go with maybe 20 and once again, I can press the space bar just to show you few moments or few frames from the outcome so you get a sense of how this effect is going to work. Very nice. Alright, let's move on. We can change the water depth if there is a need and we can also change the refractive index. Now, this refractive index is something to do with materials and if you like to see the full table of materials, and their refractive index, you can of course, Google this value and you will get to a Wikipedia page that will show you everything that you need to know. But I'm going to leave it like this because this is what we need in terms of water refractive index. We already touch upon the surface color and the surface capacity, and if you want to introduce a little bit of a shading into the mix, then you can go ahead and play with the Caustics strength. I think this is more suitable to some sort of a fabric design, so in this case, I'm just going to reset it back to its default of zero. Now, if you want, you can also play with the lighting and the materiel to control how the lighting is going to render as well as the diffuse and specular reflections and also the highlight sharpness. But usually, I'm going to leave those values as is. I think that the default works quite nice over here so I'm not going to touch on any of those options but just know that they are there. So just in order to compare between those two, this is how the Caustics effect is going to render our text and if I'm going to switch back, this is the default displacement map. So although we have nice displacement using the displacement map, now when we are using Caustics, it looks much more convincing and if I'm just going to go to the beginning and play you the result, you can get a sense of why I love this effect so much. So the next time you need to simulate a watery distortion, make sure to check out the Old but Gold Caustics effect under the Simulation Category here inside After Effect.

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