This file gives a high level overview of the changes introduced between versions, relative to version 1.0.
- #277: This will ensure defined and portable behavior across renderers.
- #256: This PR adds a safety clamp to the result of metallic F82-tint model Fresnel calculations, preventing any negative reflectance values and therefore improving physical correctness and rendering quality for metallic surfaces.
- #247: This alters the behavior of
specular_weightwhen applied to the dielectric base, so that the refraction direction is not modified byspecular_weight, as this control is designed to vary only the reflectivity without disturbing the refraction appearance. Thus the reflection highlight and the refraction direction are effectively decoupled, in an unphysical but artistically convenient way. - #240: Fixes a bug in the MaterialX graph, where the edge-tint color for the generalized_schlick_bsdf was multiplied by
specular_weight, but the whole lobe was multiplied byspecular_weightas well. - #251: Fixes a bug in the MaterialX implementation of thin-walled subsurface, where
specular_colorwas accounted for in both the BSDF weights and as an explicit multiplier. - #250: This PR ensures that the
geometry_thin_walledproperty, which indicates if a material's geometry should be treated as "thin-walled" (i.e., like a sheet or membrane without interior volume), is correctly connected to and represented within the node of MaterialX. - #231: Introduces a new parameter called
emission_weight, providing a simple$[0,1]$ dimensionless scale facto r for theemission_luminance. - #238: Prior to this change, if
specular_weightwas set to a value greater than 1, it could lead to unphysical metallic Fresnel factors > 1. By introducing the clamp, the code ensures that, regardless of the value given to specular_weight, the resulting metal Fresnel reflectance remains within a physical range.
-
#211: This won't make much difference to the look in implementations that ignore the adjacent IORs of the film, but for those that take it into account, this will make the film visible rather than invisible by default (since
specular_ioris 1.5 by default, andcoat_ior1.6). -
#217: This change enables Zeltner sheen in the reference implementation of OpenPBR, leveraging the new functionality in MaterialX.
- First release.