Ray march node added

addons/ShaderLib/RayMarching/RayMarch.gd

@@ -0,0 +1,83 @@
+@tool
+class_name VisualShaderNodeRayMarch extends VisualShaderNodeCustom
+
+func _get_name() -> String:
+	return "RayMarch"
+
+func _get_category() -> String:
+	return "RayMarching"
+
+func _get_description() -> String:
+	return "A simple ray marcher."
+
+func _get_return_icon_type() -> PortType:
+	return PORT_TYPE_SCALAR
+
+func _get_input_port_count() -> int:
+	return 6
+
+func _get_input_port_name(port: int) -> String:
+	match port:
+		0:
+			return "signed distance"
+		1:
+			return "ray origin"
+		2:
+			return "ray direction"
+		3:
+			return "max steps"
+		4:
+			return "max distance"
+		_:
+			return "distance threshold"
+
+func _get_input_port_type(port: int) -> PortType:
+	match port:
+		1, 2:
+			return PORT_TYPE_VECTOR_3D
+		3:
+			return PORT_TYPE_SCALAR_INT
+		_:
+			return PORT_TYPE_SCALAR
+
+func _get_input_port_default_value(port: int) -> Variant:
+	match port:
+		1:
+			return Vector3(0, 0, -1)
+		2:
+			return Vector3(0 ,0 ,0)
+		3:
+			return 15
+		4:
+			return 15.0
+		5:
+			return 1e-2
+		_:
+			return null
+
+func _get_output_port_count() -> int:
+	return 1
+
+func _get_output_port_name(port: int) -> String:
+	return "distance"
+
+func _get_output_port_type(port: int) -> PortType:
+	return PORT_TYPE_SCALAR
+
+func _get_global_code(mode: Shader.Mode) -> String:
+	var code: String = preload("RayMarch.gdshaderinc").code
+	return code
+
+func _get_code(input_vars: Array[String], output_vars: Array[String], mode: Shader.Mode, type: VisualShader.Type) -> String:
+	var signed_distance: String = "0.0"
+
+	if input_vars[0]:
+		signed_distance = input_vars[0]
+
+	var ray_origin: String = input_vars[1]
+	var ray_direction: String = input_vars[2]
+	var max_steps: String = input_vars[3]
+	var max_dist: String = input_vars[4]
+	var dist_threshold: String = input_vars[5]
+
+	return output_vars[0] + " = ray_march(%s, %s, %s, %s, %s, %s);" % [ray_origin, ray_direction, max_steps, max_dist, dist_threshold, signed_distance]

addons/ShaderLib/RayMarching/RayMarch.gdshaderinc

@@ -0,0 +1,14 @@
+float ray_march(vec3 ray_origin, vec3 ray_dir, int max_steps, float max_dist, float dist_threshold, float signed_dist) {
+	ray_dir = normalize(ray_dir);
+	dist_threshold = abs(dist_threshold);
+	float dist_from_origin = 0.;
+	float dist_to_surface;
+	for(int i = 0; i < max_steps; i++) {
+		vec3 point = ray_origin + dist_from_origin * ray_dir;
+		dist_to_surface = signed_dist;
+		dist_from_origin += dist_to_surface;
+		if(dist_to_surface < dist_threshold || dist_to_surface > max_dist)
+			break;
+	}
+	return dist_from_origin;
+}