In a Metal surface shader (for a custom material), the color = params.geometry().color() call returns a float4 type.
I guess that color is the interpolated color for the fragment in the triangle.
I'd like to set that color to params.surface().set_base_color(color), however set_base_color expects a half3 parameter.
How to convert from float4 to half3, and how to combine the values ? (well, I only 1.0 alfa but still...).