Photorealistic Beach Simulation in Houdini: How It's Made

Introduction

Hi! I'm Caue Rodrigues, I'm a Designer, but I have worked in Architectural Visualization for almost 20 years. VFX came to my life 2 years ago when I started using Phoenix FD and tyFlow. However, the solution which I think is highly technical and which I fell in love with is Houdini. In this article, I would like to talk about the tools I used in my recent project. 

FLIP Simulations

Speaking of my favorite solver, it's definitely FLIP. Even though it has a long calculation time, I'm always fascinated to see it's working. So, I decided to create a beach scene simulation and try FLIP SOP for my project. By using FLIP SOP, I could keep it as simple as possible (as long as you don't dive too deep into FLIP SOP).

That's what finished FLIP particles look like:

The Whitewater Simulation

The simulation of whitewater was more complex, but the calculation didn’t take much time. Here are the settings I used:

In order to keep things as simple as possible, most of the settings were almost the same as the default for whitewater. I also wanted to avoid an excessive number of particles, so I decreased the Emission. Additionally, I added Noise to break patterns a little bit. 

To achieve the desired shape for whitewater, I experimented with Repellants and Erosion. I used Erosion to remove isolated particles faster. Since the water had high turbulence, I didn't want foam to cover all surfaces. In this aspect, Erosion worked better for this purpose than lifespan.

The result of the whitewater simulation:

Setting Up the Meshes

Let's mesh it! Meshing can be challenging to achieve accuracy due to reseeding particles. The problem is that some points are covered by meshes, while others don't. I wanted to try and cover as much as possible, so I played around with the VDB and used Dilate/Erode, which had a significant role in making it work, the last ones in particular.

Here is the final mesh:

The Lighting Process

Speaking of the lighting, I used HDRI. As for the other materials, I have resorted to base Maps – Roughness and Displacement. For the materials which had wet/dry parts, I experimented with Ramp in order to make them look wet.

Caue Rodrigues, Environment/VFX Artist