public void Update(float stepSize)
{
if (!Initialized)
{
if (Mesh != null && Mesh.State == Common.ResourceLoadingState.Loaded && Skeleton == null)
{
Skeleton = Mesh.Skeleton;
}
if (Skeleton != null && Skeleton.State == Common.ResourceLoadingState.Loaded)
{
Init();
}
else
{
return;
}
}
if (CurrentAnimation == null)
return;
Time += stepSize;
if (Time >= CurrentAnimation.Length)
{
Time = 0.0f;
// Reset bind pose
for (var i = 0; i < Skeleton.BindPose.Length; i++)
{
BoneTransforms[i] = Skeleton.BindPose[i];
}
}
// Apply animation track transform
for (var t = 0; t < CurrentAnimation.Tracks.Length; t++)
{
var index = CurrentAnimation.Tracks[t].BoneIndex;
var keyFrameIndex = 0;
// Find active key frame
for (var k = 0; k < CurrentAnimation.Tracks[t].KeyFrames.Length; k++)
{
if (CurrentAnimation.Tracks[t].KeyFrames[k].Time > Time)
break;
keyFrameIndex = k;
}
var keyFrame = CurrentAnimation.Tracks[t].KeyFrames[keyFrameIndex];
var transform = keyFrame.Transform;
// Interpolate between key frames if neccecary
if (keyFrameIndex < CurrentAnimation.Tracks[t].KeyFrames.Length - 1)
{
var keyFrame2 = CurrentAnimation.Tracks[t].KeyFrames[keyFrameIndex + 1];
var alpha = Time - keyFrame.Time;
if (alpha > 0)
{
alpha = alpha / (keyFrame2.Time - keyFrame.Time);
Quaternion.Slerp(ref keyFrame.Transform.Orientation, ref keyFrame2.Transform.Orientation, alpha, out transform.Orientation);
Vector3.Lerp(ref keyFrame.Transform.Position, ref keyFrame2.Transform.Position, alpha, out transform.Position);
}
}
Quaternion.Multiply(ref Skeleton.BindPose[index].Orientation, ref transform.Orientation, out BoneTransforms[index].Orientation);
Vector3 transformedPosition;
Vector3.Transform(ref transform.Position, ref Skeleton.BindPose[index].Orientation, out transformedPosition);
Vector3.Add(ref transformedPosition, ref Skeleton.BindPose[index].Position, out BoneTransforms[index].Position);
}
WorldTransforms[0] = BoneTransforms[0];
// Apply parent transform
for (var i = 1; i < BoneTransforms.Length; i++)
{
var parentIndex = Skeleton.BoneParents[i];
Quaternion.Multiply(ref WorldTransforms[parentIndex].Orientation, ref BoneTransforms[i].Orientation, out WorldTransforms[i].Orientation);
Vector3 transformedPosition;
Vector3.Transform(ref BoneTransforms[i].Position, ref WorldTransforms[parentIndex].Orientation, out transformedPosition);
Vector3.Add(ref transformedPosition, ref WorldTransforms[parentIndex].Position, out WorldTransforms[i].Position);
}
// Calculate final bone matrix
for (var i = 0; i < WorldTransforms.Length; i++)
{
Quaternion orientation;
Quaternion.Multiply(ref WorldTransforms[i].Orientation, ref InverseTransforms[i].Orientation, out orientation);
Vector3 transformedPosition;
Vector3.Transform(ref InverseTransforms[i].Position, ref orientation, out transformedPosition);
Vector3 position;
Vector3.Add(ref transformedPosition, ref WorldTransforms[i].Position, out position);
Matrix4 translationMatrix;
Matrix4.CreateTranslation(ref position, out translationMatrix);
Matrix4 rotationMatrix;
Matrix4.Rotate(ref orientation, out rotationMatrix);
Matrix4.Mult(ref rotationMatrix, ref translationMatrix, out FinalBoneTransforms[i]);
}
}
public SkeletonInstance(Skeleton skeleton)
{
Skeleton = skeleton;
}