I'm using Amplify shader visual scripting to make tessellation and increment level of detail of the 3d mesh. 
But is not applying Catmull-Clark subdivision round smoothness. And my model still looks square and computationally expensive. I did not find nodes name Catmull-Clark or similar. Since rendering of Catmull-Clark subdivision surfaces is often mentioned as the primary application for the tessellation pipeline, my question is:
How can I make a Unity 5 Physically Based shader that includes Catmull-Clark subdivision surfaces tessellation to increase LOD? If is possible using Amplify shader nodes or Shaderforge.
In my case, The 3D models came from 3dmax [simple quad N-Gons] in OBJ format and I apply subdivision surface in Blender to get roundness. Blender use Catmull-Clark subdivision surfaces and I do not know what type of approximating method is using [https://docs.blender.org/manual/ja/dev/modeling/modifiers/generate/subsurf.html]. But I wish a more real-time dynamic approach and increase the LOD in the game based on camera proximity and omit the step of making a second model with Hi level of detail, that is a big time-consuming. I scroll down the Unity documentation and try to apply all the solutions including the Phong tessellation. But at the edges of the mark seams the 3d mesh creates noticeable big holes.
I have no idea about any Catmull-Clark subdivision types. If you can clarify that, can help. I'm really just seeking some method to round-out the shapes of the tesselated mesh.
Note that the info on Unity website about tessellation does not include Catmull-Clark subdivision and PBR: https://docs.unity3d.com/Manual/SL-SurfaceShaderTessellation.html
here is an example of Unity5 PBR with tessellation but is missing the roundness.
Shader "Standard (Tesselation)" { Properties { _Color ("Color", Color) = (1,1,1,1) _MainTex ("Albedo (RGB)", 2D) = "white" {} _BumpMap ("Normal Map (RGB)", 2D) = "bump" {} _BumpScale ("Normal Power" , Float) = 1 _Occlusion ("Occlusion Map (R)" , 2D) = "white" {} _Metallic ("Metallic (R) , Smoothness (A)" , 2D) = "black" {} _ParallaxMap ("Heightmap (A)", 2D) = "black" {} _EdgeLength ("Edge length", Range(3,50)) = 10 _Parallax ("Height", Range (0.0, 1.0)) = 0.5 } SubShader { Tags { "RenderType"="Opaque" } LOD 200 CGPROGRAM // Physically based Standard lighting model, and enable shadows on all light types #pragma surface surf Standard fullforwardshadows vertex:disp tessellate:tessEdge #include "Tessellation.cginc" sampler2D _ParallaxMap; float _EdgeLength; fixed _Parallax; float _BumpScale; sampler2D _MainTex; sampler2D _Occlusion; sampler2D _BumpMap; sampler2D _Metallic; struct appdata { float4 vertex : POSITION; float4 tangent : TANGENT; float3 normal : NORMAL; float2 texcoord : TEXCOORD0; float2 texcoord1 : TEXCOORD1; float2 texcoord2 : TEXCOORD2; }; float4 tessEdge (appdata v0, appdata v1,appdata v2) { return UnityEdgeLengthBasedTessCull (v0.vertex, v1.vertex, v2.vertex, _EdgeLength, _Parallax * 1.5f); } void disp (inout appdata v) { float d = tex2Dlod(_ParallaxMap, float4(v.texcoord.xy,0,0)).a * _Parallax; v.vertex.xyz += v.normal * d; } // Use shader model 3.0 target, to get nicer looking lighting #pragma target 3.0 struct Input { float2 uv_MainTex; }; fixed4 _Color; void surf (Input IN, inout SurfaceOutputStandard o) { // Albedo comes from a texture tinted by color fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color; o.Albedo = c.rgb; // Metallic and smoothness come from slider variables fixed4 m = tex2D(_Metallic,IN.uv_MainTex); o.Metallic = m.r; o.Occlusion = tex2D(_Occlusion,IN.uv_MainTex).x; o.Smoothness = m.a; o.Normal = normalize(UnpackScaleNormal(tex2D(_BumpMap, IN.uv_MainTex), _BumpScale)); o.Alpha = c.a; } ENDCG } FallBack "Diffuse" } 
