Apply a shader to mergedgeometry

I am having difficulty trying to apply this shader to a merged mesh. I have a set of planes that I merged. My goal is that the shader covers the entire mesh to avoid repeating.

code: SBCODE Editor
I got this shader form shadertoy: Shader - Shadertoy BETA

vUv = uv;vUv = vec2(position.x,position.z)*0.5;