Diff += max(dot(in.normal, L), 0.0001) * light_col * attenuation;
        Lo += (kD * albedo / PI + specular) * radiance * NdotL;
    }

    var out: FragmentOutput;
    var color = Diff * albedo * ao + Lo;

    // HDR tone mapping
    color = color / (color + vec3(1.0));
    // Gamma correct
    color = pow(color, vec3(1.0 / 2.2));

    out.color = vec4(color, 1.0);

does wonders for me

        Diff += max(dot(in.normal, L), 0.0001) * light_col * attenuation;
        Lo += (kD * albedo / PI + specular) * radiance * NdotL;
    }

    var out: FragmentOutput;
    var color = Diff * albedo * ao + Lo;

    // HDR tone mapping
    color = color / (color + vec3(1.0));
    // Gamma correct
    color = pow(color, vec3(1.0 / 2.2));

    out.color = vec4(color, 1.0);

does wonders for me, I take the vertex normal (in.normal) for diffuse color

        Diff += max(dot(in.normal, L), 0.0001) * light_col * attenuation;
        Lo += (kD * albedo / PI + specular) * radiance * NdotL;
    }

    var out: FragmentOutput;
    var color = Diff * albedo * ao + Lo;

    // HDR tone mapping
    color = color / (color + vec3(1.0));
    // Gamma correct
    color = pow(color, vec3(1.0 / 2.2));

    out.color = vec4(color, 1.0);

Adding the Diff does wonders for me, I take the vertex normal (in.normal) for diffuse color

        Diff += max(dot(in.normal, L), 0.0001) * light_col * attenuation;
        Lo += (kD * albedo / PI + specular) * radiance * NdotL;
    }

    var out: FragmentOutput;
    var color = Diff * albedo * ao + Lo;

    // HDR tone mapping
    color = color / (color + vec3(1.0));
    // Gamma correct
    color = pow(color, vec3(1.0 / 2.2));

    out.color = vec4(color, 1.0);

Adding the Diff does wonders for me, I take the vertex normal (in.normal) for diffuse color, it give me back the shadows

        Diff += max(dot(in.normal, L), 0.0001) * light_col * attenuation;
        Lo += (kD * albedo / PI + specular) * radiance * NdotL;
    }

    var out: FragmentOutput;
    var color = Diff * albedo * ao + Lo;

    // HDR tone mapping
    color = color / (color + vec3(1.0));
    // Gamma correct
    color = pow(color, vec3(1.0 / 2.2));

    out.color = vec4(color, 1.0);

Adding the Diff does wonders for me, I take the vertex normal (in.normal) for diffuse color, it gives me back the shadows

Some fun hardware stuff I just finished:

Built a custom control circuit for our mini-tree's battery powered lights! Designed such that each of the trees two strands can run at different voltages/brightnesses. Uses two constant voltage buck converters modules, a switch and barrel connectors. First time I've soldered in quite a few years, and I think I did a pretty good job, all things considered. Pulls 9V 0.08A out of 6 rechargeable AAs, for a total runtime of about 25 hours