Cel Shading - How To: Border Detection

[Scalia]

@blenderrendersk

Hey, I used an outline filter in a game once

uniform sampler2D bgl_RenderedTexture;
uniform sampler2D bgl_DepthTexture;
uniform vec2 bgl_TextureCoordinateOffset[9];

const float near = 0.1;
const float far = 100.0;

float depth(in vec2 coo)
{
 vec4 depth =  texture2D(bgl_DepthTexture, coo);
 return -near / (-1.0+float(depth) * ((far-near)/far));
}

void main(void)
{


    vec4 sample[9];
    vec4 border;
    vec4 texcol = texture2D(bgl_RenderedTexture, gl_TexCoord[0].st);



    for (int i = 0; i < 9; i++)
    {
        sample[i] = vec4(depth(gl_TexCoord[0].st + bgl_TextureCoordinateOffset[i])); 
    }

    vec4 horizEdge = sample[2] + sample[5] + sample[8] -
                     (sample[0] + sample[3] + sample[6]);

    vec4 vertEdge = sample[0] + sample[1] + sample[2] -
                    (sample[6] + sample[7] + sample[8]);

    border.rgb = sqrt((horizEdge.rgb * horizEdge.rgb) + 
                            (vertEdge.rgb * vertEdge.rgb));

       if (border.r > 0.8||border.g > 0.8||border.b > 0.8){
        gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
    }else{
  gl_FragColor.rgb = texcol.rgb;
        gl_FragColor.a = 1.0;
    }
}

This is the code. Using it should give you the same effect as before!
Nice project btw! Keep going

this is the shader that BlenderRenderSky uses… and he’s super cool, so you know that it will work.