Cat Cafe Diorama: Setting Up Lights and Fog

Cat Cafe Diorama: The Idea and Goal

The scene started as a four-week project at school, where we got to choose an individual project to do. I wanted to make a diorama to practice mood, lighting, and storytelling. I wasn’t sure exactly what I wanted to make though, so I went out for a walk and then came up with the cat café idea. I made a small sketch and then I went into Maya to start blocking it out.

Blockout

In Maya, I first blocked out the main shapes and imported them all together to Unreal Engine. It’s important to get things into Unreal as soon as possible since it will look different there than it does in Maya. After I adjusted the sizes of things until they felt right, I broke up the blockout into separate assets and reimported them to Unreal.

My initial design was only one floor, but I felt it was too boring and had no depth, so I added a dining area with stairs.

By the end of the project, I received great feedback from my teacher Pontus Karlsson that I feel greatly improved the diorama. I had too many straight lines: the building’s corners were completely vertical, the stairs were all straight horizontal and vertical lines, etc. So I added more triangles to the meshes to make everything a bit more wonky, which made the whole diorama feel more alive and interesting.

Modeling and Texturing

After blocking out and getting all the shapes as I wanted them, I started focusing on each asset one by one. My usual way is to make the high poly either in Maya or ZBrush and bake it down on the low poly in Substance Painter. The UVs are nothing fancy, I just unwrap them and try to put the seams either where they’d be hidden or where I’d have hard edges anyway.

Speaking of texturing, I have some basic materials I’ve made myself in Substance Designer, which I used on some assets. Others are created layer by layer with different generators and fills or painted by hand. I just played around with the textures until I was happy with them. I wasn’t looking for realistic materials or anything like that in this diorama.

The base floor is made of very basic meshes with two tiling materials: the cobblestone ground and the stone wall. I made both materials in Substance Designer.

It’s great to be able to send the textures to UE4, see what they look like and very easily adjust them as needed. I went back and forth between Substance Designer and Unreal quite frequently.

Lighting and Final Rendering

The lightbulb meshes all have emissive materials on them. Around the colorful string lights, I put a couple of point lights with corresponding colors. The lights on the building walls have spotlights and in front of the window, I put point lights.

Tilmann Milde gave me the tip to use volumetric fog on the lights, which greatly improved the overall mood. I did that by using ExponentialHeightFog with Volumetric Fog turned on. The Fog Inscattering Color was changed to a red hue that matches the Skysphere color. Then, I also turned down the Fog Max Opacity so that the Skysphere wasn’t covered by the fog. Finally, I raised the Volumetric Scattering Intensity in some of the lights to get the fog around the lights. The intensity depends, ranging from 15 to 300, - just use whatever number that makes it look good.

I also made some simple Niagara particle systems around the lights for that extra sparkle.

When taking the final rendered pictures, I turned on Depth of Field in my Post-Process. It helps a lot with softening the image and creating the focal points.

Hanna Stenow, 3D Artist

Interview conducted by Arti Sergeev