Scalable normals is a material technique that uses tiling maps and region masks to approximate high-resolution normal maps at a significantly smaller memory footprint. While originally introduced to support large crowds of characters (as part of the MetaHuman Collection and MetaHuman Instance assets), it is useful in any scenario where multiple MetaHuman characters appear on screen simultaneously and texture memory usage is a concern.
While the impact is greatest in crowd scenarios, scalable normals are also useful when you want multiple MetaHuman NPCs on screen at once while keeping texture memory usage low.
Enable the scalable normals tickbox on Assembly to use this feature.
The table below provides a comparison between a Cinematic Assembly and an assembly utilizing Scalable Normals, including an A/B comparison of the two configurations.
| Cine Assembly (4K textures) | Scalable Normals Assembly |
|---|---|
3x unique 4K maps (Base Color, Normal, SRMF) | 3x unique 1K maps (Base Color, Normal, SRMF) |
1x unique 512x512 Scatter map | 1x unique 512x512 Scatter map |
2x 1K optional microtiling maps | 7x shared 512x512 maps |
60MB disk space footprint | 10MB disk space footprint (3MB unique maps, 7MB shared across all MetaHumans using scalable normals) |
