[SOLVED] Pass data from a shader to its Dependency shader? Or set Dependecy shader data?

Terrain shaders use dependencies like this:

Dependency "AddPassShader" = "Hidden/TerrainEngine/Splatmap/Standard-AddPass"

When more than 4 textures are added to a terrain then the AddPass shader is called to render the 5th one and any other textures following.

I have modified the terrain shaders and gave them extra properties and I wonder if there is any way I can set a property value in a dependency shader?

For the FirstPass shader I can just add a property and then change that property in the material I attach it to, using the inspector. But you never see the dependency shader properties so how can I set those through script?

 

Okay I got it working.

Simply use the Terrain.SetSplatMaterialPropertyBlock() like this:

Terrain terrain = transform.gameObject.GetComponent<Terrain>();
MaterialPropertyBlock prop = new MaterialPropertyBlock();
terrain.GetSplatMaterialPropertyBlock(prop);
prop.SetFloat("_MyValue", 2.0f);
terrain.SetSplatMaterialPropertyBlock(prop);

This will set "_MyValue" in both the FirstPass and the AddPass shader if both has that property (or else just in the one that has it).

 

Sadly this works only after version 5.5, I can not find it in previous versions of Terrain API.