#version 330 core
in vec2 vUV;         // [-1,1] range — distance from blob centre
out vec4 fragColor;
uniform vec3  uColor;
uniform float uFalloff;  // gaussian width: larger = tighter core
void main() {
    float d = length(vUV);
    if (d > 1.0) discard;
    float intensity = exp(-uFalloff * d * d);
    fragColor = vec4(uColor * intensity, intensity);
}