Breakdown 2/3:

• City Glow
• City environment
• Window
• Skies

City Glow

At this point, I pondered on how the city is to be made. I considered making a couple of modular buildings for PCG later on but dropped it as its time consuming. I accidentally pondered onto a scene in Mobile Suit Gundam GQuuuuuuX.

Mobile Suit Gundam GQuuuuuuX Special Announcement Trailer

I was intrigued by the city glow in the trailer, it immediately became a must have feature in the short film. To recreate it, I plan to have several really simple PCG graph consists of a bunch of cubes with different patterns to compliment each other to help build a city. I first create a cube with bright emissive materials to represent the dot. The pattern and density is controlled by various nodes in this settings which spawn the box according to the noise pattern. You can also control the size of the boundary box that house the entire boxes.

The image i want to share is how each set of PCG behaves according to the settings I set. In total, there are only 4 types. I separate them according to the size, density and emissive colour.

For the bright city glow, I first placed the large city onto the terrain where I think the main area will be with reference to real life city. Followed by the concentrated city and the normal city to create an effect with high to low concentration of bright cubes.

I also noticed my initial idea of having 4 maps actually hindered how the PCG will cover on the map, there are areas which PCG cannot generate the cubes on the top surface due to overlapping of the map. The shadow cast by the directional light also need to be addressed. For this, I first turn off cast shadow for the landscape. Then I move the lights away from overlap area so that it feel less unnatural.

Reference tutorial for PCG:

How to Procedurally Generate 3D Environments in Unreal Engine 5 | FULL PCG WORKFLOW

City environment

For the much more 'detailed' city in the final scene, I used AccuCities 3D City Models Sample to quickly put a city scene due to time constrain. I knew the scene will not be too detailed for the video so I made texture with settings that can be tweaked. I focus on two things: Surface textures and window

For the surface, I want a material instance to be modular so that I can quickly tweak and duplicate onto the building mesh. My reference was mostly from Patlabor 2's environment, most of the buildings are painted and unsaturated. I used grunge map from substance painter to replicate the noise in the movie. For material, I used the same material from the cellshader tutorial and modify it. The cell shader material function is simply skipped and the input is set to accept only 2 grunge maps, base colour, uv scaling and values for contrast.

Window

For windows, I struggled with creating the similar modularity of textures except its for windows. The input only accepts textures that are cropped from Photoshop which is just the photo and the mask being cropped out. The input also allow uv scaling, colour, contrast and brightness of the emissive.

Technically, both material should help eliminate the need to create many plane. Noticeable tiling can be avoided via editing the mask to show which area to lit.

Quickly, I decorated the scene and added lightings. I took reference from cities like Akira and Cowboy Bebop for the night scene. The buildings are separated with colours for different section. As for lightings and windows, I placed only for area which are needed for the scene.

Skies

Lastly for the skies, I used Stylized Volumetric Clouds Shader for stylize clouds. I tweak around the settings including directional lights until it matches my reference image.