Fragment fluid

#version 450
#extension GL_ARB_separate_shader_objects : enable

layout(binding = 1) uniform sampler2D texSampler;

struct Vertex{
    vec3 pos;
    vec3 color;
    vec2 texCoord;
};

layout(binding = 2) buffer storage{
    Vertex vertices[];
} st;

layout(location = 0) in vec3 fragPos;
layout(location = 1) in vec2 fragTexCoord;
layout(location = 2) flat in int index;

layout(location = 0) out vec4 outColor;

float e = 2.718281828;
float iso = 0.2;
float k = 4.0;

float skalarFeld(vec3 x){
    float s=0;
    for(int i=0; i<16; ++i){
        s = s + pow(e, -k * length(x - st.vertices[i].pos));
    }
    return s;
}

void main() {

    for( float f=0; f <= 2.0; f=f+0.05){
        float s=skalarFeld(fragPos * f);
        if(s >= iso){
            outColor = vec4(fragPos, 1.0); // * texture(texSampler, fragTexCoord);
            break;
        }else
        {
            outColor = vec4(1.0, 1.0, 1.0, 1.0);
            outColor = vec4(s, s, s, 1.0);
            break;
        }
    }


    //outColor = vec4(st.vertices[index].pos, 1.0);
    //outColor = vec4(fragPos, 1.0);
}