I've found the only way to control texture animation for Displacement Modifier - using Empty and setting it as "Object" in texture mapping settings. It is ok when you have one or two or even ten objects, but what if you got thousands? Instead of animating just one texture and for example setting texture coordinates in modifiers to Global you have to manually add thousands of empties and manually link each one to needed object? The best thing of course would be the possibility to somehow use node editor for controlling textures used in modifiers. I think I remember that in previous versions there was a way to control texture mapping right in textures tab, changing offset, scale, etc. - less comfortable but still usable - but it seems to be gone from 2.8. So is using the Empty the only way left to control texture animation for Displacement modifier?