feat: more work on tree graphics

project/materials/tree_abstractor.gdshader

@@ -0,0 +1,19 @@
+shader_type spatial;
+
+uniform sampler2D albedo : hint_default_black, source_color;
+
+void vertex() {
+	
+}
+
+void fragment() {
+	// Called for every pixel the material is visible on.
+	vec4 col = texture(albedo, UV);
+	ALPHA = col.w;
+	ALBEDO = col.xyz;
+}
+
+//void light() {
+//	// Called for every pixel for every light affecting the material.
+//	// Uncomment to replace the default light processing function with this one.
+//}