The WMS that I am using supports opaque/transparent layers. An opaque layer is a layer which is generally translucent except where the image is. A dated but good analogy is an old overhead projector.
I believe that transparent layers are not part of the WMS spec, but are an extension.
Openlayers supported this by allowing the developer to pass a 'transparent' parameter at the time the layer is constructed.
Transparent layers are useful for showing information like borders, roads, ...
I am wondering if Cesium supports transparent layers? I have looked through the code and did not see any attributes or parameters which someone could set to indicate that the layer is transparent.
The behavior that I am seeing on a transparent layer is that the transparent part of the layer is appearing black on the globe meaning that I have to turn the alpha down, which affects the whole layer and not just the transparent part.
Thanks in advance
Jerry