By default the layer material panel when opened by clicking the “material” icon on Layers panel opens in “Modal” style (can’t do anything in viewport until it is closed". But once we open any of the bitmap texture slots to add a texture, or when the texture is the to edit it, the dialog becomes Modeless (can start interacting with Rhino again, rotate view, pick objects etc.) Wondering if this is a bug or a feature, I like it Modeless in general, sometimes to evaluate materials change its good to spin the model around without closing the panel, but not sure if there are problematic implications of that. If not, maybe it should be modeless by default?
–jarek