CREATE AN UNDERWATER SCENE IN UE4
In this tutorial you will learn tips on how to create a fantasy underwater scene in Unreal Engine 4 using techniques from AAA game pipelines. You will also get a better understanding of how to block out the necessary components for a strong composition with an interesting narrative. We will then look at different methods of adding foliage including traditional modelling techniques and adding Speedtree foliage to the scene. In the final stages we will explore lighting and add caustics and the final polish, which will bring the whole scene together.
Block out the scene I wanted to show something beautiful in the dragon and nest, and then draw the eye to the boat and oil spill to make the contrasting emotion of the scene really strong. I made use of the rule of thirds and used the most saturated colours in the scene to make the dragon the initial focus. I then used the leading lines of the kelp, the dragon’s gaze and the fish to draw attention to the boat so that the viewer discovers the story as they look at the scene. Nailing this in the blockout is crucial to the success of the image.
Shape the kelp The kelp foliage was key in the composition of this scene and was created using 3ds Max as I needed very specific shapes. I began by making one straight section of kelp that can tile and looks interesting from all angles. I then created a spline, which made up the shape of the kelp. I duplicated the mesh to create the correct length and then used the path deform modifier in Max to deform the kelp to fit the spline. I made variants of the model by duplicating and changing the spline to different shapes and by tweaking the deformed mesh to give it more shape variation.
Add movement to the kelp When making the leaf UVS, I laid out the base of the leaf at the bottom of the texture and the tip of the leaves at the top. Now, by using a vertical gradient to mask this, we can have the leaf base static and the tips moving, which will give us some nice leaf sway but allow us to keep the overall composition that the kelp shape is allowing. To do this, multiply a sine node by a gradient texture and plug this into the world position offset of your material. Adding a multiplier means that you can control the strength of the effect.
Speedtree foliage The small grasses and algae bushes are made using Speedtree. I began by creating a simple blades generator and tweaking the properties to define the radius of the plant. By tweaking the frequency and the length segments, I had precise control of the polycount and optimisation. I enabled the wind before saving the file and importing in to Unreal. Once in Unreal, add a Wind Directional Source and your foliage will sway. For the plants, I tweaked the wind animation properties in Speedtree to get a slow, swaying movement that looked as if it belonged underwater with drifting currents.