Clear material property values.

Graphics.DrawMesh copies the passed property block, so the most efficient way of using it is to create one block and reuse it for all DrawMesh calls. Use Clear to clear block's values, and AddFloat, AddVector, AddColor, AddMatrix to add values.

	var aMesh : Mesh;
	var aMaterial : Material = new Material(Shader.Find("VertexLit"));
	function Update() {
		var materialProperty : MaterialPropertyBlock = new MaterialPropertyBlock();
		// Clear any property and add a red color
		materialProperty.Clear();
		materialProperty.AddColor("_Color", Color.red);
		Graphics.DrawMesh(aMesh, Vector3(5,0,0), Quaternion.identity,
				  aMaterial, 0, null, 0, materialProperty);
		// Clear any property and add a green color
		materialProperty.Clear();
		materialProperty.AddColor("_Color", Color.green);
		Graphics.DrawMesh(aMesh, Vector3(-5,0,0), Quaternion.identity,
				  aMaterial, 0, null, 0, materialProperty);
	}

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    public Mesh aMesh;
    public Material aMaterial = new Material(Shader.Find("VertexLit"));
    void Update() {
        MaterialPropertyBlock materialProperty = new MaterialPropertyBlock();
        materialProperty.Clear();
        materialProperty.AddColor("_Color", Color.red);
        Graphics.DrawMesh(aMesh, new Vector3(5, 0, 0), Quaternion.identity, aMaterial, 0, null, 0, materialProperty);
        materialProperty.Clear();
        materialProperty.AddColor("_Color", Color.green);
        Graphics.DrawMesh(aMesh, new Vector3(-5, 0, 0), Quaternion.identity, aMaterial, 0, null, 0, materialProperty);
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	public aMesh as Mesh

	public aMaterial as Material = Material(Shader.Find('VertexLit'))

	def Update() as void:
		materialProperty as MaterialPropertyBlock = MaterialPropertyBlock()
		materialProperty.Clear()
		materialProperty.AddColor('_Color', Color.red)
		Graphics.DrawMesh(aMesh, Vector3(5, 0, 0), Quaternion.identity, aMaterial, 0, null, 0, materialProperty)
		materialProperty.Clear()
		materialProperty.AddColor('_Color', Color.green)
		Graphics.DrawMesh(aMesh, Vector3(-5, 0, 0), Quaternion.identity, aMaterial, 0, null, 0, materialProperty)