How to pass an array to a shader?

Questions & Answers
1

Is there a way to pass an array of floats to a shader?

3

Starting with Unity 5.4, there is native “arrays in shaders” support. Material.SetFloatArray, Shader.SetGlobalFloatArray, MaterialPropertyBlock.SetFloatArray

2

Currently that is possible, but cumbersome. E.g. in the shader, you can do float myarray[100], and then that becomes individual float material properties (myarray0, myarray1, …, myarray99) that can be set from scripting. So cumbersome + somewhat high overhead of applying them one by one internally.

For example, take this shader code

Shader "Custom/ArrayTest" {
	Properties {
	}
	SubShader {
		Tags { "RenderType"="Opaque" }
		LOD 200
		
		CGPROGRAM
		#pragma surface surf Standard fullforwardshadows
		#pragma target 3.0

		float myarray[3];

		struct Input {
			float2 uv_MainTex;
		};

		void surf (Input IN, inout SurfaceOutputStandard o) {
			o.Albedo = float3(myarray[0], myarray[1], myarray[2]);
		}
		ENDCG
	} 
	FallBack "Diffuse"
}

And a script to test it. Must be placed on the same object.

using UnityEngine;
using System.Collections;

public class Test : MonoBehaviour {

	void Awake() {
		var material = GetComponent<Renderer>().sharedMaterial;
		material.SetFloat("myarray0", 1);
		material.SetFloat("myarray1", 1);
		material.SetFloat("myarray2", 0);
	}
}

Hope in the future Unity will add proper arrays support.