using System.Collections.Generic; using UnityEngine; namespace MLAgents { /// /// Ray 2D perception component. Attach this to agents to enable "local perception" /// via the use of ray casts directed outward from the agent. /// public class RayPerception2D : RayPerception { Vector2 endPosition; RaycastHit2D hit; /// /// Creates perception vector to be used as part of an observation of an agent. /// Each ray in the rayAngles array adds a sublist of data to the observation. /// The sublist contains the observation data for a single ray. The list is composed of the following: /// 1. A one-hot encoding for detectable objects. For example, if detectableObjects.Length = n, the /// first n elements of the sublist will be a one-hot encoding of the detectableObject that was hit, or /// all zeroes otherwise. /// 2. The 'length' element of the sublist will be 1 if the ray missed everything, or 0 if it hit /// something (detectable or not). /// 3. The 'length+1' element of the sublist will contain the normalised distance to the object hit. /// NOTE: Only objects with tags in the detectableObjects array will have a distance set. /// /// The partial vector observation corresponding to the set of rays /// Radius of rays /// Angles of rays (starting from (1,0) on unit circle). /// List of tags which correspond to object types agent can see public List Perceive(float rayDistance, float[] rayAngles, string[] detectableObjects) { perceptionBuffer.Clear(); // For each ray sublist stores categorical information on detected object // along with object distance. foreach (float angle in rayAngles) { endPosition = transform.TransformDirection( PolarToCartesian(rayDistance, angle)); if (Application.isEditor) { Debug.DrawRay(transform.position, endPosition, Color.black, 0.01f, true); } float[] subList = new float[detectableObjects.Length + 2]; hit = Physics2D.CircleCast(transform.position, 0.5f, endPosition, rayDistance); if (hit) { for (int i = 0; i < detectableObjects.Length; i++) { if (hit.collider.gameObject.CompareTag(detectableObjects[i])) { subList[i] = 1; subList[detectableObjects.Length + 1] = hit.distance / rayDistance; break; } } } else { subList[detectableObjects.Length] = 1f; } perceptionBuffer.AddRange(subList); } return perceptionBuffer; } /// /// Converts polar coordinate to cartesian coordinate. /// public static Vector2 PolarToCartesian(float radius, float angle) { float x = radius * Mathf.Cos(DegreeToRadian(angle)); float y = radius * Mathf.Sin(DegreeToRadian(angle)); return new Vector2(x, y); } } }