Animate voxel models on Unity

PivotRotator.cs

using UnityEngine;

namespace VoxelModel
{
    [ExecuteInEditMode]
    public class PivotRotator : MonoBehaviour
    {
        private static readonly float gizmoSize = 0.1f;
        private static readonly Color gizmoColor = Color.yellow;

        [SerializeField] private Vector3 point;
        public Vector3 rotation;

        private Vector3 WorldPivot()
        {
            return transform.TransformPoint(point);
        }

        private Quaternion WorldRotation()
        {
            return  transform.rotation * Quaternion.Inverse(transform.localRotation) * Quaternion.Euler(rotation);
        }

        void Update()
        {
            transform.SetRotationAround(WorldPivot(), WorldRotation());
        }

        void OnDrawGizmosSelected()
        {
            Gizmos.color = gizmoColor;
            Gizmos.DrawWireSphere(WorldPivot(), gizmoSize);
        }
    }

    public static class TransformExtensions
    {
        public static void SetRotationAround(this Transform transform, Vector3 point, Quaternion rotation)
        {
            var position = rotation * Quaternion.Inverse(transform.rotation) * (transform.position - point) + point;
            transform.SetPositionAndRotation(position, rotation);
        }
    }
}

VertexColorBlend.shader

Shader "VoxelModel/VertexColor-Blend" {
	Properties {
		_Color ("Color", Color) = (1,1,1,1)
		_MainTex ("Albedo (RGB)", 2D) = "white" {}
		_SubTex ("Albedo (RGB)", 2D) = "white" {}
		_Ratio ("Ratio", Range(0,1)) = 0.0
	}
	SubShader {
		Tags { "RenderType"="Opaque" }
		LOD 200

		CGPROGRAM
		#pragma surface surf Standard fullforwardshadows

		#pragma target 3.0

		sampler2D _MainTex;
		sampler2D _SubTex;

		struct Input {
			float2 uv_MainTex;
			float2 uv_SubTex;
		};

		fixed4 _Color;
		half _Ratio;

		void surf (Input IN, inout SurfaceOutputStandard o) {
			fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
			half4 sub = tex2D(_SubTex, IN.uv_SubTex);
			o.Albedo = lerp (c.rgb, sub.rgb, _Ratio);
			o.Alpha = c.a;
		}
		ENDCG
	}
	FallBack "Diffuse"
}

VertexColorDepthOffset.shader

Shader "VoxelModel/VertexColor-DepthOffset" {
	Properties {
		_Color ("Color", Color) = (1,1,1,1)
		_MainTex ("Albedo (RGB)", 2D) = "white" {}
		_DepthOffset ("Depth Offset", Float) = 0.0
	}
	SubShader {
		Offset [_DepthOffset] , [_DepthOffset]

		Tags { "RenderType"="Opaque" }
		LOD 200

		CGPROGRAM
		#pragma surface surf Standard fullforwardshadows

		#pragma target 3.0

		sampler2D _MainTex;

		struct Input {
			float2 uv_MainTex;
		};

		fixed4 _Color;

		void surf (Input IN, inout SurfaceOutputStandard o) {
			fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
			o.Albedo = c.rgb;
			o.Alpha = c.a;
		}
		ENDCG
	}
	FallBack "Diffuse"
}