Another strange thing that I don't understand; when putting a value in the Z of the localize cloud parameters, without checking localize (!), the cloud disappears. I'm trying to make fire follow terrain. I've got a decent setup with smoke and fire within one cloud layer, but the altitude restriction of the smoke logically won't work when following terrain, so I have to make another cloud layer for smoke.
When "move textures with cloud" is enabled, all of your shaders are translated, in this case by 1000 in the Z axis. This affects the shaders that are causing it to follow the terrain. If you want some shaders to be world space, but not all of them, you can use a Transform Input Shader with "use world space".
Matt
Thanks Matt. I had the silly misconception that the parameters only had to do with the localizing feature, but I see the logic now.