Color4 constructor from Col3c, set alpha to 1.
Color4 constructor from Col3c, set alpha to 1.

Color4 constructor from Col3c initialized the fourth component to 1/255.
This is unintuitive and inconsistent with the overloaded constructor
from Col3f, which initializes the fourth component to 1.0.

embree/embree,embree/embree,embree/embree,Sjoerdie/embree,Sjoerdie/embree,Sjoerdie/embree,embree/embree,Sjoerdie/embree