Godot smoke shader test

smoke_shader.shader

shader_type spatial;

uniform sampler2D mask;
uniform float min_scale = 0.0;
uniform float max_scale = 1.0;

varying float scale;


float range_lerp(float value, float istart, float istop, float ostart, float oend) {
	float ilerp = (value - istart) / (istop - istart);
	return ostart + (oend - ostart) * ilerp;
}


void vertex () {
	scale = length(MODELVIEW_MATRIX[2].xyz);
}


void fragment () {
	float l = texture(mask, UV).r;
	float s = range_lerp(scale, min_scale, max_scale, 0.0, 1.0);
	if (s > l) {
		discard;
	}
	ALBEDO = vec3(clamp(scale, 0.0, 1.0));
}

Small experiment to dissolve smoke particles as they get larger