# `gs.surfaces.BSDF`

A Disney principled BSDF surface, exposing the full set of physically based rendering parameters. `gs.surfaces.Default` is a subclass of `BSDF` with no added parameters, so the substantive PBR controls documented here, such as `specular_trans`, `diffuse_trans`, and `metallic_texture`, apply equally to both.

```{eval-rst}
.. autoclass:: genesis.options.surfaces.BSDF
```