How to show a normal map on the INSIDE of a mesh: POSSIBLE?

Questions & Answers
1

Hello!

I have an object (a) floating through space and want to place a big low poly mesh (object b) + normal map texture surrounding my object so I can project nebulas on it.

So in short object A (= size 1) is moving in the middle of object B (= size 1000).

How can I make the normal map on my big object B project on the INSIDE of the mesh?
What kind of (altered) shader do I need for that?

I hope my question makes sense!

2

I found the answer, it’s rather straight forward. Might have looked more into this before asking.
I found a unity page with shader examples (also with normals) here: https://docs.unity3d.com/Manual/SL-SurfaceShaderExamples.html

Just add a line (right after the Tags{} ) that says: ‘Cull Front’.

Shader "CUSTOM/NewImageEffectShader" 
{
	Properties 
	{
		_MainTex ("Texture", 2D) = "white" {}
		_BumpMap ("Bumpmap", 2D) = "bump" {}
		_RimColor ("Rim Color", Color) = (0.26,0.19,0.16,0.0)
		_RimPower ("Rim Power", Range(0.5,8.0)) = 3.0
	}

	SubShader 
	{
		Tags { "RenderType" = "Opaque" }

		Cull Front

		CGPROGRAM
		#pragma surface surf Lambert
		struct Input 
		{
			float2 uv_MainTex;
			float2 uv_BumpMap;
			float3 viewDir;
		};

		sampler2D _MainTex;
		sampler2D _BumpMap;
		float4 _RimColor;
		float _RimPower;

		void surf (Input IN, inout SurfaceOutput o) 
		{
			o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb;
			o.Normal = UnpackNormal (tex2D (_BumpMap, IN.uv_BumpMap));
			half rim = 1.0 - saturate(dot (normalize(IN.viewDir), o.Normal));
			o.Emission = _RimColor.rgb * pow (rim, _RimPower);
		}

		ENDCG
	}

	Fallback "Diffuse"
}