Clarence Lowe discussed step-by-step how he created a Japanese scene with Golden Ginkgo trees and breathed life into it with subtle animations of the wind and falling leaves.
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Hello everyone! I am Clarence Lowe, an Environment Artist from Austin, Texas. After finishing high school in Northern California I went to Westwood College at the Denver North Campus. Since moving to Austin I have worked at such video game studios as Edge of Reality, Bluepoint Games, and Hellfire Games. My most exciting project was at Bluepoint Games working on Uncharted: The Nathan Drake Collection for the PS4.
Japan - Golden Ginkgo Trees: Inspiration
I am a huge fan of the newly released Ghost of Tsushima for PS4. I was greatly moved by how the team at Sucker Punch captured the beauty and zen of the Tsushima countryside while in the middle of a Mongolian invasion.
When I was doing some research about the local plantlife of Japan, one that caught my attention was the Golden Ginkgo Tree. It originated from China and thousands of people travel to Japan and other regions just to witness the golden leaves during the autumn season.
My goal for this scene was to capture the call to adventure, the Hero’s Journey. Like in Ghost of Tsushima I wanted to keep the scene grounded in realism as much as possible. The Torii gate and bridge are all from real-world references and I knew I had to really nail the look of the Golden Ginkgo Trees to make the scene tangible.
I had great in-game concepts from screen captures from my PS4 of the areas in Ghost of Tsushima I wanted to reference. Other references were of Ginkgo leaves in the fall and the trees themselves, and a lot of feudal Japan bridges and landscapes. Once I gathered my references from in-game, google images, and Pinterest, I compiled them into a reference sheet using PureRef. PureRef is a great program that gives you a lot of control and keeps your concepts in one place.
Unreal Engine is always my first choice when it comes to building a game level or scene. I wanted to learn how to create a realistic terrain and watched several YouTube videos on how to use World Machine. Fractal terrain generators like Advanced Perlin Noise helped change the initial landscape using noise to cut away features. After creating layers of erosion in World Machine I exported a landscape heightmap.
The first flora pass in Unreal involved importing a static mesh of a Ginkgo Tree. To do this, I set up my Ginkgo Trees using SpeedTree. In SpeedTree, I started with a blank tree and added the trunk node using Absolute Mode under the All Generation dropdown menu.
Mimicking from nature, I created Big Branches, then Little Branches, then Twigs under the Interval dropdown menu, while selecting the Randomize Tab under the Generation menu. Referring back to my Ginkgo Tree reference, they have long trunks with the branches starting high above.
Substance Painter is my main go-to texturing program. The Shinkyo Bridge replica was modeled in Maya and textured in SP, the wood plank flooring was a procedural texture created in Substance Designer. When I use SP I rely heavily on my Material ID map. This is due to my workflow which is a combination of Fill Layers with Black Masks to section out each part of the mesh. It’s an efficient way to get immediate results rather than hand painting the mesh as a whole. If I paint in details, most of the time it’s Height details or in the Black Mask itself to control generator masking values.
Making static meshes is fun and exciting, but the next step for my scene was animating the feel of this level. Going back to my inspiration Ghost of Tsushima, I wanted to capture the zen of feudal Japan.
To create the wind effect in Unreal I created a Master Material. Master Materials are the parent materials that I can create instances from. This is very common in material creation in Unreal and instances provide a lot of control.
I created a SimpleGrassWind node and attached a MaterialExpressionConstant by hitting the 1 key + Left mouse clicking the graph. Then I converted the constant to a parameter with a default value of 1.0. I then repeated this step and set the default value to 0.5 on the second parameter. Plugging these values into the SimpleGrassWind node gave me WindIntensity (1.0) and WindWeight (0.5). In that same node, I then plugged in the RGB channel of the Master Material Albedo Parameter, thus telling the material that any albedo texture will bend and move fast or slow compared to the instanced wind weight values.
To create the falling leaves, I made a Master Material. I then imported a single leaf png texture with transparency. I set the blend mode in the material editor to Masked and the Shading Model is set to Two Sided Foliage with Two-Sided checked in the box. This way, leaves will have textures on both sides and look more realistic. I then made a Material Instance of that Master Material.
Leaves on the Ground
The leaves on the ground in this scene were created using the Foliage Paint setting in Unreal. I made another Master Material using a leaf texture I created in Adobe Photoshop. Unlike the single leaf used for the tree branches, the brush textures are multiple leaves that can create a scattered or piled look when painted onto the landscape.
Assembling the final scene went in three passes. First, importing my meshes and placing my Unreal Actors such as Reflection Captures, Player Start, Atmospheric Fog, Light Mass Importance Volume, and Post Process Volume. Then I made sure the textures and mesh lightmaps were baked and optimized for the level build. And finally, setting up the lighting.
Lighting is a whole art style in itself and I want to learn more about proper lighting for AAA games. In my Unreal scene, I used a Directional Light to act as the main sunlight source. The level Sky Light can be used to change the feel of the weather like Fall versus Spring. For the foliage of the trees, I placed a Spot Light in the thicket of the leaves and changed the mobility setting to Static. This causes fewer errors and is cheaper to use during the light baking process. I then used Point Lights to add flares of sunlight on my meshes and player path.
I found that to achieve the feel of autumn in the scene, it was key to adjust the rotation of the Directional Light and the intensity of the Exponential Height Fog. As far as colors go, I left most lights with their default settings. The warmth comes from the tree’s static mesh material combined with the direction of the main light source and fog.
The main challenge in this scene was lighting. Lighting is an issue that I think a lot of artists have to tackle. Unreal Engine provides so many lighting features, but I feel my main struggle was to light an exterior scene and make it feel like autumn. There was a balance of creating a spread of dead leaves and still have the scene feel lively.
Another challenge behind this scene was not to make it feel messy. Too many particle effects and wind can really clutter the player’s view. Naturally, leaves are messy, but I wanted to have a clear player path to convey the Hero’s Journey.