Intro to Toolbag Custom Shaders

// 🎨 Color
uniform vec3 uColor; //color  name "My Color"  default 0.5,0.5,0.5

// 🗃️ Dropdown
uniform int uDropdown; //name "My Dropdown"  default 0  labels "Option 1" "Option 2" "Option 3"

// 🎚️ Slider
uniform float   uSlider; //name "My Slider"  default 1.0  min 0  max 10

#define DISTMARCH_STEPS 128
#define DISTMARCH_MAXDIST 256.

uniform vec3 uColor1; //color  name "Color 1"  default (14.0 / 255.0), (135.0 / 255.0), (163.0 / 255.0)
uniform vec3 uColor2; //color  name "Color 2"  default (11.0 / 255.0), (96.0 / 255.0), (178.0 / 255.0)

// 🌊 Distance Fields

float spheredf(vec3 pos, float r) { return length(pos) - r; }

float opRep(vec3 p, vec3 c)
{
    // Modulus Repeat on XZ
    vec3 spread = max(vec3(0.0, 0.0, 0.0), vec3(uCustomAnimationTime - 1.0,
                                                uCustomAnimationTime - 1.0,
                                                uCustomAnimationTime - 1.0));
    vec3 q = mod(abs(p), c) - 0.5 * c;
    q.y = p.y;
    // Wave effect
    float yy = sin(uCustomAnimationTime + .3 * p.x) +
               cos(uCustomAnimationTime * .9 + .2 * p.z);
    q += .5 * vec3(0.0, yy, 0.0);
    return spheredf(q, .1);
}

vec2 scenedf(vec3 p)
{
    p.y += max(2.0 / (uCustomAnimationTime + .001), 0.001);
    vec2 obj = vec2(opRep(p, vec3(2.5, 2.5, 2.5)), p.y);
    return obj;
}

vec3 distmarch(vec3 ro, vec3 rd, float maxd)
{
    float epsilon = 0.001;
    float dist = 10. * epsilon;
    float t = 0.;
    float material = -1.0;
    float iterations = 0.;

    for (int i = 0; i < DISTMARCH_STEPS; i++)
    {
        if (abs(dist) < epsilon || t > maxd) break;
        // advance the distance of the last lookup
        t += dist;
        vec2 dfresult = scenedf(ro + t * rd);
        dist = dfresult.x;
        material = dfresult.y;
        iterations++;
    }

    if (t > maxd)
    {
        iterations = -1.0;
    }
    return vec3(t, iterations, material);
}

void CustomAlbedo(inout FragmentState s)
{
    vec2 uv = s.screenTexCoord;
    uv.y = 1.0 - uv.y;
    vec4 outColor = vec4(0., 0., 0., 0.);

    // 🎥 Setup Camera
    vec3 camOrigin = vec3(45.0, -32.0, 45.0);
    vec3 camDir = normalize(-vertexEye);
    // aspect ratio
    vec2 st = uv.xy - .5;
    st *= (float(screenCoord.y) / float(screenCoord.x));

    // Perspective Transform
    float fov = 3.142 * .625;
    vec3 iu = vec3(0., 1., 0.);
    vec3 iz = camDir;
    vec3 ix = normalize(cross(iz, iu));
    vec3 iy = cross(ix, iz);
    vec3 dir = normalize(st.x * ix + st.y * iy + fov * iz);

    // 🥁 Scene Marching
    vec3 scenemarch = distmarch(camOrigin, dir, DISTMARCH_MAXDIST);
    float sceneCol = 0.0;
    sceneCol = clamp(sceneCol, 0.0, 1.0);

    // 🌫️ Fog
    if (scenemarch.x > 0.0001)
    {
        sceneCol = clamp(scenemarch.y, 0.,
                         mix(1.0, 0.0, smoothstep(10., 180., scenemarch.x)));
    }

    // 🖼️ Output
    outColor.xyz = mix(uColor1, .95 * uColor2,
                       smoothstep(0.0, 1.0, scenemarch.z)) *
                   sceneCol;
    outColor.a = sceneCol;

    // Write to albedo/baseColor
    s.albedo = outColor;
    s.baseColor = outColor.xyz;
}

#ifdef Albedo
#undef Albedo
#endif
#define Albedo CustomAlbedo