// barrier overlay, but shaped like the texture

void SetupMaterial( inout Material mat )
{
	vec4 col = getTexel(vTexCoord.st);
	vec3 grad = texture(bartex,vec2(0.,fract(vTexCoord.t+timer))).rgb;
	mat.Base.rgb = grad*col.a;
	mat.Base.a = col.a;
}