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358 行
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using System.Collections.Generic;
using UnityEngine;
namespace Unity.MLAgents.Extensions.Sensors
{
/// <summary>
/// Abstract class for managing the transforms of a hierarchy of objects.
/// This could be GameObjects or Monobehaviours in the scene graph, but this is
/// not a requirement; for example, the objects could be rigid bodies whose hierarchy
/// is defined by Joint configurations.
///
/// Poses are either considered in model space, which is relative to a root body,
/// or in local space, which is relative to their parent.
/// </summary>
public abstract class PoseExtractor
{
int[] m_ParentIndices;
Pose[] m_ModelSpacePoses;
Pose[] m_LocalSpacePoses;
Vector3[] m_ModelSpaceLinearVelocities;
Vector3[] m_LocalSpaceLinearVelocities;
bool[] m_PoseEnabled;
/// <summary>
/// Read iterator for the enabled model space transforms.
/// </summary>
public IEnumerable<Pose> GetEnabledModelSpacePoses()
{
if (m_ModelSpacePoses == null)
{
yield break;
}
for (var i = 0; i < m_ModelSpacePoses.Length; i++)
{
if (m_PoseEnabled[i])
{
yield return m_ModelSpacePoses[i];
}
}
}
/// <summary>
/// Read iterator for the enabled local space transforms.
/// </summary>
public IEnumerable<Pose> GetEnabledLocalSpacePoses()
{
if (m_LocalSpacePoses == null)
{
yield break;
}
for (var i = 0; i < m_LocalSpacePoses.Length; i++)
{
if (m_PoseEnabled[i])
{
yield return m_LocalSpacePoses[i];
}
}
}
/// <summary>
/// Read iterator for the enabled model space linear velocities.
/// </summary>
public IEnumerable<Vector3> GetEnabledModelSpaceVelocities()
{
if (m_ModelSpaceLinearVelocities == null)
{
yield break;
}
for (var i = 0; i < m_ModelSpaceLinearVelocities.Length; i++)
{
if (m_PoseEnabled[i])
{
yield return m_ModelSpaceLinearVelocities[i];
}
}
}
/// <summary>
/// Read iterator for the enabled local space linear velocities.
/// </summary>
public IEnumerable<Vector3> GetEnabledLocalSpaceVelocities()
{
if (m_LocalSpaceLinearVelocities == null)
{
yield break;
}
for (var i = 0; i < m_LocalSpaceLinearVelocities.Length; i++)
{
if (m_PoseEnabled[i])
{
yield return m_LocalSpaceLinearVelocities[i];
}
}
}
/// <summary>
/// Number of enabled poses in the hierarchy (read-only).
/// </summary>
public int NumEnabledPoses
{
get
{
if (m_PoseEnabled == null)
{
return 0;
}
var numEnabled = 0;
for (var i = 0; i < m_PoseEnabled.Length; i++)
{
numEnabled += m_PoseEnabled[i] ? 1 : 0;
}
return numEnabled;
}
}
/// <summary>
/// Number of total poses in the hierarchy (read-only).
/// </summary>
public int NumPoses
{
get { return m_ModelSpacePoses?.Length ?? 0; }
}
/// <summary>
/// Get the parent index of the body at the specified index.
/// </summary>
/// <param name="index"></param>
/// <returns></returns>
public int GetParentIndex(int index)
{
if (m_ParentIndices == null)
{
return -1;
}
return m_ParentIndices[index];
}
/// <summary>
/// Set whether the pose at the given index is enabled or disabled for observations.
/// </summary>
/// <param name="index"></param>
/// <param name="val"></param>
public void SetPoseEnabled(int index, bool val)
{
m_PoseEnabled[index] = val;
}
/// <summary>
/// Initialize with the mapping of parent indices.
/// The 0th element is assumed to be -1, indicating that it's the root.
/// </summary>
/// <param name="parentIndices"></param>
protected void Setup(int[] parentIndices)
{
#if DEBUG
if (parentIndices[0] != -1)
{
throw new UnityAgentsException($"Expected parentIndices[0] to be -1, got {parentIndices[0]}");
}
#endif
m_ParentIndices = parentIndices;
var numPoses = parentIndices.Length;
m_ModelSpacePoses = new Pose[numPoses];
m_LocalSpacePoses = new Pose[numPoses];
m_ModelSpaceLinearVelocities = new Vector3[numPoses];
m_LocalSpaceLinearVelocities = new Vector3[numPoses];
m_PoseEnabled = new bool[numPoses];
// All poses are enabled by default. Generally we'll want to disable the root though.
for (var i = 0; i < numPoses; i++)
{
m_PoseEnabled[i] = true;
}
}
/// <summary>
/// Return the world space Pose of the i'th object.
/// </summary>
/// <param name="index"></param>
/// <returns></returns>
protected internal abstract Pose GetPoseAt(int index);
/// <summary>
/// Return the world space linear velocity of the i'th object.
/// </summary>
/// <param name="index"></param>
/// <returns></returns>
protected internal abstract Vector3 GetLinearVelocityAt(int index);
/// <summary>
/// Update the internal model space transform storage based on the underlying system.
/// </summary>
public void UpdateModelSpacePoses()
{
using (TimerStack.Instance.Scoped("UpdateModelSpacePoses"))
{
if (m_ModelSpacePoses == null)
{
return;
}
var rootWorldTransform = GetPoseAt(0);
var worldToModel = rootWorldTransform.Inverse();
var rootLinearVel = GetLinearVelocityAt(0);
for (var i = 0; i < m_ModelSpacePoses.Length; i++)
{
var currentWorldSpacePose = GetPoseAt(i);
var currentModelSpacePose = worldToModel.Multiply(currentWorldSpacePose);
m_ModelSpacePoses[i] = currentModelSpacePose;
var currentBodyLinearVel = GetLinearVelocityAt(i);
var relativeVelocity = currentBodyLinearVel - rootLinearVel;
m_ModelSpaceLinearVelocities[i] = worldToModel.rotation * relativeVelocity;
}
}
}
/// <summary>
/// Update the internal model space transform storage based on the underlying system.
/// </summary>
public void UpdateLocalSpacePoses()
{
using (TimerStack.Instance.Scoped("UpdateLocalSpacePoses"))
{
if (m_LocalSpacePoses == null)
{
return;
}
for (var i = 0; i < m_LocalSpacePoses.Length; i++)
{
if (m_ParentIndices[i] != -1)
{
var parentTransform = GetPoseAt(m_ParentIndices[i]);
// This is slightly inefficient, since for a body with multiple children, we'll end up inverting
// the transform multiple times. Might be able to trade space for perf here.
var invParent = parentTransform.Inverse();
var currentTransform = GetPoseAt(i);
m_LocalSpacePoses[i] = invParent.Multiply(currentTransform);
var parentLinearVel = GetLinearVelocityAt(m_ParentIndices[i]);
var currentLinearVel = GetLinearVelocityAt(i);
m_LocalSpaceLinearVelocities[i] = invParent.rotation * (currentLinearVel - parentLinearVel);
}
else
{
m_LocalSpacePoses[i] = Pose.identity;
m_LocalSpaceLinearVelocities[i] = Vector3.zero;
}
}
}
}
/// <summary>
/// Compute the number of floats needed to represent the poses for the given PhysicsSensorSettings.
/// </summary>
/// <param name="settings"></param>
/// <returns></returns>
public int GetNumPoseObservations(PhysicsSensorSettings settings)
{
int obsPerPose = 0;
obsPerPose += settings.UseModelSpaceTranslations ? 3 : 0;
obsPerPose += settings.UseModelSpaceRotations ? 4 : 0;
obsPerPose += settings.UseLocalSpaceTranslations ? 3 : 0;
obsPerPose += settings.UseLocalSpaceRotations ? 4 : 0;
obsPerPose += settings.UseModelSpaceLinearVelocity ? 3 : 0;
obsPerPose += settings.UseLocalSpaceLinearVelocity ? 3 : 0;
return NumEnabledPoses * obsPerPose;
}
internal void DrawModelSpace(Vector3 offset)
{
UpdateLocalSpacePoses();
UpdateModelSpacePoses();
var pose = m_ModelSpacePoses;
var localPose = m_LocalSpacePoses;
for (var i = 0; i < pose.Length; i++)
{
var current = pose[i];
if (m_ParentIndices[i] == -1)
{
continue;
}
var parent = pose[m_ParentIndices[i]];
Debug.DrawLine(current.position + offset, parent.position + offset, Color.cyan);
var localUp = localPose[i].rotation * Vector3.up;
var localFwd = localPose[i].rotation * Vector3.forward;
var localRight = localPose[i].rotation * Vector3.right;
Debug.DrawLine(current.position+offset, current.position+offset+.1f*localUp, Color.red);
Debug.DrawLine(current.position+offset, current.position+offset+.1f*localFwd, Color.green);
Debug.DrawLine(current.position+offset, current.position+offset+.1f*localRight, Color.blue);
}
}
}
/// <summary>
/// Extension methods for the Pose struct, in order to improve the readability of some math.
/// </summary>
public static class PoseExtensions
{
/// <summary>
/// Compute the inverse of a Pose. For any Pose P,
/// P.Inverse() * P
/// will equal the identity pose (within tolerance).
/// </summary>
/// <param name="pose"></param>
/// <returns></returns>
public static Pose Inverse(this Pose pose)
{
var rotationInverse = Quaternion.Inverse(pose.rotation);
var translationInverse = -(rotationInverse * pose.position);
return new Pose { rotation = rotationInverse, position = translationInverse };
}
/// <summary>
/// This is equivalent to Pose.GetTransformedBy(), but keeps the order more intuitive.
/// </summary>
/// <param name="pose"></param>
/// <param name="rhs"></param>
/// <returns></returns>
public static Pose Multiply(this Pose pose, Pose rhs)
{
return rhs.GetTransformedBy(pose);
}
/// <summary>
/// Transform the vector by the pose. Conceptually this is equivalent to treating the Pose
/// as a 4x4 matrix and multiplying the augmented vector.
/// See https://en.wikipedia.org/wiki/Affine_transformation#Augmented_matrix for more details.
/// </summary>
/// <param name="pose"></param>
/// <param name="rhs"></param>
/// <returns></returns>
public static Vector3 Multiply(this Pose pose, Vector3 rhs)
{
return pose.rotation * rhs + pose.position;
}
// TODO optimize inv(A)*B?
}
}