UnityでShaderをささっと使う

[Create] -> [Shader]でshaderを下のような感じに書き換えて、MaterialにD&D。そのMaterialを適当なCubeとかにD&D。んで、Scriptから自分で定義した値に適当な値をぶっこむ。簡単です。

MyShader.shader

Shader "Custom/GLSL Shader" {
	Properties {
		_Point("a point in world space", Vector) = (0., 0., 0., 1.0)
	}
	SubShader {
		Pass {
			GLSLPROGRAM
			
			uniform vec4 _Point;

#ifdef VERTEX
void main()
{
	gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}
#endif

#ifdef FRAGMENT
uniform vec4 _SinTime;
//uniform vec4 _Point;

void main()
{
//	gl_FragColor = _SinTime;
	gl_FragColor = _Point;
}
#endif

			ENDGLSL
		}
	}
}

ShaderController.cs

using UnityEngine;
using System.Collections;

public class ShaderController : MonoBehaviour {

	// Use this for initialization
	void Start () {
	}
	
	// Update is called once per frame
	void Update () {
		var mx = Input.mousePosition.x / (float)Screen.width;
		var my = Input.mousePosition.y / (float)Screen.height;
		renderer.sharedMaterial.SetVector("_Point", new Vector4(mx, my, (mx + my)/2.0f, 1.0f));
	}
}