Full error message text:
Affecting only a part of a base material with a Decal material is only supported if both materials are Corona Physical Materials. Color, specular and roughness 'Affect Base' settings of decal(s) '<Corona Decal Name>' will be ignored.
Using the "Affect Base" feature of Corona Decal with Color, Specular, or Roughness options is possible only with Corona Physical Materials. If any Corona Decal, in which any of those options is enabled, or any object, onto which such Corona Decal is projected, is using a different material type than Corona Physical Material, then this error message appears.
The Corona Decal object is using a Corona Legacy Material, which triggers the error message.
The solution is to either:
- Make sure that all Corona Decals and objects they are projected onto are using Corona Physical Materials. In this case all "Affect Base" options will be affecting any underlying objects' original base material properties as expected:
- Disable Color, Specular, and Roughness options in the problematic Corona Decal's "Affect Base" rollout. In this case, the Decal will not affect the underlying objects' base color, specular, or roughness properties.
Note: this error message may also appear when a Corona Light object is placed within the range of a Corona Decal's influence:
In such cases, the solution is to exclude any Corona Lights using the Include/Exclude button available in the Corona Decal options:
See also: Corona Decal at the Chaos Documentation Portal