Setting Up Vegetation for Alien Island in 3D

Introduction 

Hi, I'm Morgane, an Environment Artist student from Bordeaux, France. I'm graduating from Artside School later this year! I learned the fundamentals and discovered 3D during my first two years, and I went on to specialize in 3D environments for a further two years. I’m proud to present to you a project I did in my third year as part of an introductory course!

Vegetation Project

This project was carried out as part of an introduction to SpeedTree software under the supervision of Arnaud Claudet, vegetation artist on Avatar: Frontiers of Pandora (the breakdowns I’m presenting are based on the workflow he used for the game).

For two months, we explored the software and various workflows for creating vegetation. To help us learn the software as effectively as possible, each type of plant was created using a slightly different workflow, allowing us to gradually deepen our understanding of the software. The task we were given was to create an alien island based on a specific biome; so my main source of inspiration was the biome I had been assigned, the savannah. 

I began my project by conducting both technical and visual research on the savanna. I carried out my research online, as well as in books or documentaries. Something I sought above all was to understand how vegetation functions in this type of environment and to identify its characteristics. To create a plausible and realistic environment, understanding how it works is essential. Here are some references I used.

After the research phase, I produced a first draft using sketches of what I wanted my plants to look like. Most of my plants bear no resemblance to the initial sketches I produced, but they gave me a starting point for what I wanted to achieve.

Blockout & Modeling

I started to create my first rough models in SpeedTree based on the concepts I’d made. As I explored the various settings the software offers, I experimented with my plants to select the ones with the most potential and refine them further. Discovering all the settings and having fun combining them proved to be very inspiring. The blockout phase is very useful for planning what needs to be done and optimizing as many aspects as possible, such as textures and topology.

My first project in SpeedTree was the grass, which is the easiest element to create. I started by creating a texture of grass blades in Substance 3D Designer, which I then imported into SpeedTree. I then modeled my plane based on the texture and arranged the grass blades into flat tufts. After assembling various packs of grass blades, I extracted a texture from them, which I used again in SpeedTree. I recreated the mesh based on the grass tuft texture to produce a 3D assembly. The process was pretty much the same for bushes and flowers.

For Gramineae, the process was slightly different. I modeled the different parts of my plant and created maps from them for texturing; I then reassembled the textured elements in SpeedTree.

For the plants in volume, I combined the workflows I used for the previous plants. I started by creating a rough version of the plant to figure out what I would need later on for the trees. For example, the trunk only needs a tileable texture – the same goes for the large branches – but for smaller branches, I did a first texture with only a leaf that I assembled into a branch in SpeedTree, which I then reassembled into my whole texture.

Most of the plants I have created have a group version in which the same plant appears several times with slight variations. To ensure diversity in my vegetation, I applied procedural variance. It was one of the most subtle concepts to grasp. The aim of this variation is to be able to introduce randomness without affecting the global visual appearance of the plant. When creating my plant arrangements, I used BMS and Gestalt theory, which explains how the brain perceives and organizes shapes and forms, resulting in more readable, recognizable, and memorable outcomes.

Texturing

Here are a few maps I created in SpeedTree prior to my texturing work. These maps have been particularly useful for fine-tuning my textures; one consists of various gradients broken down into RGB channels, and the second is an RGB breakdown of the different elements that make up part of my plant. I’ve also got normal, opacity, and noise maps directly from SpeedTree.

For this plant, here’s what my Designer graph looks like.

The graph looks pretty intimidating at first glance, but it's actually not that complicated. For this texturing process, I learned how to use a custom node that contained the maps I extracted from SpeedTree, namely my gradient map (the first map above), which I used with an RGBA split to extract all my gradients individually; my map with my various elements separated into RGB (the second map), for which I also used an RGBA split to isolate all the elements of my plants from one another. Additionally, I possess an AO map, a normal map from which roughness was extracted via an RGBA split, a noise map, and an opacity map that yielded an ID map through a flood fill followed by another.

After setting up all the maps in the custom node, I’m starting on my first set of plants. So I began by retrieving the masks for the plants I want to texture. I start by applying a base color to my different elements while adding variations in value using BMS noise, which is mostly the same noise with different tiling, as well as a top-to-bottom gradient from one of the channels in the gradient map, after which I blend the different base colors into a single texture. I then add color variations between each element that makes up my plant using one of the gradients from the gradient map. I also wanted to add another gradient to the exterior, so I created a mask using a radial gradient that I modified to follow the areas I wanted to affect. And I finished by adding a highlight and the noise map retrieved from SpeedTree to enhance the sense of volume. Here is the result.   

Final Scene

Before assembling the scene, I created my island’s landscape; during my research phase, I also did some research about geology. As part of the introductory course, I also discovered WorldCreator. I created a bunch of landscapes through 20-minute experimentation exercises; each round, we had to try a new parameter and get the best result. I ended up using the very first one I made. I then created four textures for it in Substance 3D Designer: one for the cliffs, one for the rocks, and two for the ground with sand and mud.

When my assets and island were done, I imported everything into Unreal Engine. To put the scene together, I created groups that bring the different types of plants together into sub-biomes. To scatter them in the scene, I used the PCG in Unreal. Most of my plants are scattered in patches with a large plant in the center and progressively smaller plants around the edges. I also proceeded to change some colors directly in Unreal; this way, I could make my different plant types match together in their sub-biome. We also had a shader that allowed us to have small hue shifts between our assets, giving them diversity without adding noise.

Lighting & Rendering

For my lighting, I tried to create different atmospheres for all four of my sub-biomes, whilst ensuring they complemented the feeling the plants were giving within them. To achieve this lighting, I had the chance to have the help of Philémon Caron. I used Lumen, with simple lighting featuring directional light and a skylight with an HDRI map, some volumetric fog, sky atmosphere, and post-processing. To start my lighting, I used the Unity Lighting & Exposure Cheat Sheet values. In the post-process, I adapted the min and max EV and reduced shadow contrast and Toe.

I also worked on my lighting and composition by regularly switching my screen to black-and-white. This made it easy for me to see where the viewer's attention was being drawn. Here, for example, the focus point is clearly the flower in the middle; when turning the image to black and white, the flowers are in the light and stand out in contrast to the surrounding darkness and the god rays hitting them.

For the composition, I use simple composition rules like the rule of thirds. I just navigate through my scene looking for good shots. I’ve rendered my cinematic and shots with the Movie Render Queue and tweaked parameters to improve my render quality. I used a 1.85:1 aspect ratio to make my render look more cinematic.

Conclusion

Since this project was completed as part of a course, the main challenges I faced were meeting deadlines, quickly absorbing a large amount of information, and maintaining a fast pace of work. In the end, however, this project was extremely instructive and rewarding to complete. It was the first project of this scale that I’d ever undertaken, and I’m pretty happy with how it turned out. If I had to give one piece of advice to someone just starting, I’d tell them to always try to understand how what they’re trying to do actually works in real life so they can make their work as believable as possible; this applies to both realistic and stylized pieces.

If you want to see more, here is a video of my schoolmates' work:

And if you want to see more of my work, find me on ArtStation and LinkedIn.

Morgane Muller, Environnement Artist

Interview conducted by Gloria Levine