How can I vary a shader over all 2D space?

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:bust_in_silhouette: Asked By Argysaur

I am trying to apply a water shader to a certain tile in my tileset, but I want the animation to move across all connected tiles, and not simply play an identical animation on every tile.

To do this I would like the animation to vary over the entire 2D space rather than only vary on the UV space within each tile.

I have tried to use FRAGCOORD, however this seems to track the camera/viewport, rather than respect global coordinates. I’ve also tried POINT_COORD but this seems to return 0 every time.

Forgive me, I am very new to Godot