You may remember I was working on a 1950’s diner project just about a week ago. Well, one morning I saw this photo on instagram and it immediately inspired me to wanna try doing something similar in Unreal Engine.

Using Lights to Achieve Caustics

After gathering some reference, the idea was to use lights in order to get the effect of water caustics. Here’s what that looked like:

And this is how I set up the light function:

However, during an interview I got asked what would be a more optimised way to get the same effect - and then I realised I should use a panning emissive texture instead on the walls and floor.

Doing Things the Better Way

Even though the lights were giving me the result I wanted, any technical artist would’ve screamed if they saw 3 lights being used that way. Dodged a bullet there.

Regardless, I initially set up the emissive texture the same way I set up the light function, using a Motion 4 Way node. Then I realised, during the same interview I got asked to delete that node and make it from scratch instead. That way I would get the result I wanted with as few instructions as possible, removing any bloat/functionality I didn’t need.

Here’s the new and improved effect:

And how it’s set up:

This scene has a grand total of one directional light at the moment. I’m quite happy with it, but I might increase the chromatic aberration on the texture a little bit.

Project Goals

The biggest goal for this project is to get the water to move with the player, probably using render targets. I would also like to add some custom specularity to it, so that it reflects the light in a pretty way.

I will most definitely update as soon as I get either of the two working in engine. I’ve already learned a lot during this project and I’ve only really started working on in a couple days ago. I’m happy to be able to say that each day is like a school day, the learning never stops and that’s what keeps tech art fun.

I’m also glad I was able to get such valuable feedback during my interview, and put it to good use straight away. Constructive feedback is an important part of development and I feel like I realise it now more than ever.

Anyway, that’s all for now, thank you so much for reading, take care and hope to see you on here again soon!