Add fresnel effect to fragment shader

Unity Engine
1

Hi there, I am trying to add a fresnel/rim effect to a fragment shader, but am encountering some issues in getting the correct rim color to apply.

fixed4 frag (v2f i) : SV_Target
            {
                // Sample texture
                half4 col = tex2D(_MainTex, i.uv) * _Tint; // Texture times tint color;

                // View direction of camera
                float3 viewDir = normalize(_WorldSpaceCameraPos - i.worldPos);
                half rim = 1.0 - saturate(dot(normalize(viewDir), i.normal));
                half4 newCol = half4(col * _RimColor);
                newCol.a = col.a;
                newCol *= pow(rim, _RimPower);
                col = newCol;

                return col;
            }

This snippet seems to apply the fresnel effect correctly, but the rim color isn’t displaying correctly. The rim color appears as black in-game regardless of what color I set it to in the inspector. Does anyone have any insight as to what I’m doing wrong here? Thanks!

3359194--263006--Screen Shot 2018-01-18 at 9.17.23 AM.png
3359194--263006--Screen Shot 2018-01-18 at 9.17.23 AM.png760Ă—432 65.5 KB

2

What exactly are you expecting? You’re multiplying your texture by the tint color, the rim color, and by the inverted dot product. That’s a lot of multiplying.

I suspect you really want a lerp in there someplace, but it depends on what the final look you’re going for is.

half rim = 1.0 - saturate(dot(normalize(viewDir), i.normal));
col.rgb = lerp(col.rgb, col.rgb * _RimColor.rgb, pow(rim, _RimPower));

1 Like
3

Thanks, this is indeed the look I was trying to get.