Added automatic procedural level of detail to planets

godot/Shaders/Planet/PlanetShading.gdshader

@@ -0,0 +1,18 @@
+shader_type spatial;
+
+uniform float min_elevation;
+uniform float max_elevation;
+uniform sampler2D elevation_color;
+
+varying float height;
+
+void vertex() {
+	height = length(VERTEX);
+}
+
+void fragment() {
+	float t = height/(max_elevation-min_elevation)- (min_elevation / (max_elevation-min_elevation));
+	vec3 color = texture(elevation_color, vec2(t, 0.0)).rgb;
+	ALBEDO = color;
+}
+