Add Vector4(XYZW) and Color(RGBA) support in Shader Editor graphs
Right now only Vector3 and RGB + separate alpha is supported. It would be more consistent to support as well Vector4 and RGBA in a shader graph and would help in the case of passing parameters or doing math.
3 Comments
In shading colors (reflectivity) and transparency (opacity) are separated as they should not be mixed. IMO adding alpha channel to color sockets of for example Principled Shader would make it very confusing to developers and even users as it isn't compatible with PBR materails. Current inconsistency (compared to textures) is because of this.
My goal was to add 2 new format (Vector4 and RGBA) and keep RGB and Vector3 as it is, which means also new nodes to split and combine RGBA and Vector4.
Really want this. As a workaround, you can use the add-on called Vertex Color Master. github.com/andyp123/blender_vertex_color_master
It allows you to isolate and paint vertex alpha. I haven't found a way to display it in Blender, but it will export to other render engines, notably Threejs.