lava shader

shader_type spatial;
render_mode shadows_disabled;
//render_mode unshaded;

uniform vec4 main_color : hint_color;
uniform vec4 intersection_color : hint_color;
uniform float intersection_max_threshold = 0.5;
uniform sampler2D displ_tex : hint_white;
uniform sampler2D noise1;
uniform sampler2D noise2;
uniform float displ_amount = 0.6;
uniform float near = 0.15;
uniform float far = 300.0;

float linearize(float c_depth) {
    c_depth = 2.0 * c_depth - 1.0;
    return near * far / (far + c_depth * (near - far));
}

void fragment(){
    // partie LAVA
    float t = TIME * 0.005;
    vec3 v1 = texture(noise1, UV +t).rgb;
    vec3 v2 = texture(noise2, UV -t).rgb;
    float sum = (v1.r + v2.r) - 0.7;

//  vec4 back = vec4(1.0, 0.0, 0.0, 1.0);
    float fin = 0.0;
    if(sum > 0.0 && sum < 0.2) fin = 0.2;
    if(sum > 0.2 && sum <= 0.7) fin  = 0.0;
    if(sum > 0.7 ) fin  = 1.0;

    vec3 lava = vec3(fin) + mix(main_color.rgb, intersection_color.rgb, 0.5) ;

//  partie FOAM
    float zdepth = linearize(texture(DEPTH_TEXTURE, SCREEN_UV).x);
    float zpos = linearize(FRAGCOORD.z);
    float diff = zdepth - zpos;

    vec2 displ = texture(displ_tex, UV - TIME / 20.0).gb;
    displ = ((displ * 2.0) - 1.0) * displ_amount;
    diff += displ.x;

    vec4 col =  mix(intersection_color, main_color, step(intersection_max_threshold, diff));
    vec3 final = col.rgb+ lava;

    ALBEDO = final;
    EMISSION =final * 1.5;

}