shader_type spatial;
render_mode blend_mix, depth_draw_opaque;

global uniform float global_snow_amount;

uniform vec4 snow_color : source_color = vec4(0.95, 0.98, 1.0, 1.0); 

void fragment() {
    vec3 world_normal = (INV_VIEW_MATRIX * vec4(NORMAL, 0.0)).xyz;
    float up_dot = dot(world_normal, vec3(0.0, 1.0, 0.0));
    float snow_mask = smoothstep(1.0 - global_snow_amount, 1.1 - global_snow_amount, up_dot);
    snow_mask *= step(0.01, global_snow_amount);

    ALBEDO = snow_color.rgb;
    ALPHA = snow_mask;
    
    ROUGHNESS = 0.3; 
    SPECULAR = 0.5;
}