OnTexture drawing for cellular automata

Hi guys,

I try to implement a simple cellular automata that will fill a Zelda style (top view) 2D map. As the level sizes vary a lot I want to design it as dynamic as possible.

My thoughts: - create fully transparent texture - scale object of texture to level / area bounds - scale texture size to my desired "per tile"-resolution - Update(): draw state of the cellular automata on every frame with SetPixels()

The main problem right now is that the texture "loses" its transparency when it gets resized (it gets a milky white look). The drawing of the water map works and the texture is transparent when skipping the resize.

The texture is attached to a SpriteRenderer with "Sprite-Default" material.

Is this the way to go for a 2D growing water on a tilemap or is there an easier / faster approach?

Thank you :)