C#: Changing Terrain Textures

Hello!

I am looking to change a terrain texture and texture size in runtime.

As shown above, I have a terrain object and a texture. I am trying to change the texture albedo and size during runtime.

I think I am on the right track, through trying to edit the splatPrototype. Is this the approach I should use? Below is my current code -- it compiles without error, however fails to change the texture...

 public Material PlanetBiomeMap; // assigned to valid material
 
 Texture2D TerrainMap = (Texture2D)PlanetBiomeMap.mainTexture; // extracts texture from biome map
 
 Terrain PlanetTerrain = transform.Find ("Terrain").GetComponent<Terrain>(); // finds terrain
 TerrainData PlanetTerrainData = PlanetTerrain.terrainData; // terrain's data object
  
 PlanetTerrainData.splatPrototypes[0].texture = TerrainMap; // *I think?* changes first texture

All help is appreciated!