Generating anime-style 3D assets for Japanese indie games
Anime-style 3D is a specific aesthetic with specific technical requirements: hard-edge outlines, flat colour regions with minimal surface noise, and a lighting model that reads clearly at small screen sizes. Getting this look from a general-purpose 3D generator used to require significant post-processing. The anime style preset in Marble Voyage is built to produce it directly.
What the anime style preset changes
The preset adjusts three things: the geometry generator biases toward cleaner silhouettes with fewer small surface details, the texture generator produces flat colour regions with sharp transitions rather than gradual gradients, and the normal map is softened to reduce the micro-surface detail that reads as realistic but looks wrong in a cel-shaded context.
The outline is not baked into the texture. It is generated as a separate mesh shell that you can enable or disable in your target engine. In Unity, the shell uses an inverted-hull shader. In Unreal Engine 5, it uses a post-process outline material. Both are included in the export package when you use the anime preset.
Writing prompts for anime-style characters
Anime character design has a specific vocabulary that the model responds to well. Terms like 'long flowing hair', 'large expressive eyes', 'school uniform', 'armoured pauldrons', and 'katana at the hip' all produce recognisable results. Combine them with a colour palette description: 'silver hair, deep blue eyes, white and gold armour'.
For non-character assets like environments and props, the anime preset works well with architectural subjects. 'Traditional Japanese shrine gate in anime style, red lacquer, worn wood' produces a torii that reads clearly at game camera distances.
Integrating anime assets into a Unity project
Export the character as GLB with the Unity preset and the anime shell mesh included. In Unity, assign the inverted-hull shader to the shell mesh and set the outline width to 0.02 in world units for a character that is approximately 1.8 metres tall. Adjust the outline colour to a slightly darker version of the character's primary colour rather than pure black for a softer look.
Lighting for anime-style characters works best with a single strong directional light and a low-intensity ambient fill. Avoid point lights close to the character surface, as they break the flat-colour illusion.
The anime preset is a starting point, not a finished product. The best results come from treating the first generation as a base and refining through two or three chat turns.