When you create a cloud layer in Terragen 4 most of them will use Cloud Layer v3 (new cloud shading) by default. This gives you more realistic cloud rendering (new in Terragen 4, as you know
). The cloud types that do not use Cloud V3 in the Add Cloud Layer list are all 3 of the Global presets and the High-level: Cirrus (2D). All others use V3 cloud shading, or a variation of it (Easy Cloud). To clarify further, many of the new presets use the "Easy Cloud", which uses the shading of Cloud V3, but has simplified controls and less power, in exchange for more realistic out-of-the-box cloud shapes that match the cloud type of the preset. To create a generic Cloud V3, you would use the "Mid-level: Generic" preset, which gives you a general-purpose Cloud V3 layer with full settings available.
If you look in the title bar of the node settings for any node (including cloud nodes), or hover over them in the node network for tooltips, you'll also see the type/base name of the node displayed after the custom/user-created name. So for example in the default scene if you create a Mid-level: Generic cloud from the Add Cloud Layer menu in the Atmosphere Layout, then hover over the node in the node network view, you'll see: "Name: Altocumulus layer 01" "Type: Cloud layer v3". If you double-click to open that same node, in the title bar of the pop-up settings window you'll see "Altocumulus layer 01 (Cloud layer v3)". If you created one of the other presets (aside from Global and 2D), you would see "Easy Cloud" instead of "Cloud layer v3".