X-ray normal based contour rendering

result

principle ：

Calculate the rendered color based on the normal of the object surface . Compare the direction of the normal of the object surface with the direction of the line of sight

The closer the normal direction is to the camera direction , Explain the position closer to the center of the object , 

conversely , Indicate the position at the edge

Key code ：

            v2f vert (appdata_full v)

            {

                v2f o;

                o.pos = mul(UNITY_MATRIX_MVP,v.vertex);

                o.viewDir = normalize(TransformWorldToObject(GetCameraPositionWS()));

                o.normal = v.normal;

                return o;

            }

            float4 frag (v2f i) : COLOR

            {

                float rim = 1 - saturate(dot(i.viewDir,i.normal ));

                float4 color = _RimColor*pow(rim,_RimPower);

                return color;

            }