Art Spotlight: Gradient Sushi Cart

About Myself

My name is Sebastian Irmer. I’m 33 years old and I’m living in Germany. I’ve studied applied media management at UAS Mittweida. After receiving my Bachelor of Arts degree I’ve been working as a 3D artist in Berlin. My passion for games began with the “SNES era” and since then I’ve wanted to create games. Currently, I’m working on multiple projects for browsers and mobile devices.

The Reason for Gradient Textures

In addition to my work, I am expanding my techniques and my technical understanding in order to be able to incorporate this knowledge into future projects. So I came across the principle of gradient textures. If you want to develop 3D games on mobile devices, you will encounter many problems, especially when it comes to the VRAM and GPU. Polygons are cheap but textures are heavy and load very slowly. For this reason, you should always try to keep them as small as possible. Gradient textures allow just that. I practiced this technique on several projects and the gradient sushi cart was the most recent iteration.

By chance, I came across the concepts of Ein Choi. These are well balanced in color and have strong silhouettes. This is exactly what I’m looking for in my private projects.

Tools

I have been working professionally with Cinema 4D and Photoshop for over 10 years. However, I also use Blender and Substance Painter for my private projects.

Modeling

I start by looking closely at the concept. Most of the time, I don’t like details because they either don’t make sense or aren’t elaborate enough. I change the concept in the appropriate places and start modeling.

Modeling is very important when working with gradient textures. You basically draw the texture with polygons. If you want to have certain patterns, the polygons must be arranged and modified so that the gradient texture can transform them into the desired pattern. I think about strong silhouettes and give a model enough thickness and weight to adhere to the style defined in the concept.

Texturing

When I’m satisfied with the model, I create the gradient texture. Here I make sure that the gradient is at least 8 pixels wide and the total size does not exceed 64×64 pixels. In the end, the texture is barely 20KB in size and can be used up to an entire level. This way, the texture can be processed very quickly by VRAM and GPU. In addition, using a single texture for many models can save a lot of draw calls if you have the appropriate setup in your gaming engine. In terms of color, I keep the gradients very rich in contrast in order to be able to better depict light and shadow on the models.

When I have filled the gradient texture with all the colors I need, I start unwrapping the model. Unwrapping, in this case, works differently than normal. I reduce the verts to straight lines and put them in the middle of the gradient. With the individual verts, I control where the colors should become lighter and darker. Remember that the topology of the model is important. It has to be structured in a way, that you have enough verts in the right places to paint with. I unwrap every single part of the model this way. In the end, I reduce everything to one mesh and start the fine-tuning.

Setup on Sketchfab

I keep the material setup in Sketchfab very simple. I put the base color on 1 and the emission on 0.4. With emission, I can determine how strongly the light of the scene can interact with the model. I personally like it when the shadow on the model is weaker because that makes the details more visible. Sketchfab has a fairly extensive post-processing pipeline that I use to give my model the finishing touches. Sharpness and tone mapping are particularly useful. In the future, I would like to see options for cell shading effects. This would be great for models with gradient textures.