// ref. vertex_transformations.h, construct_deformed_cube_instance_matrix()
public Matrix ConstructDeformedCubeInstanceMatrix(ref Vector4UByte boneIndices, ref Vector4 boneWeights, out Matrix localMatrix)
{
localMatrix = LocalMatrix;
Matrix ret = localMatrix;
if (EnableSkinning)
{
Vector3 offset = ComputeBoneOffset(ref boneIndices, ref boneWeights);
Vector3 translationM = ret.Translation;
translationM += offset;
ret.Translation = translationM;
}
return ret;
}
public Vector3 ComputeBoneOffset(ref Vector4UByte boneIndices, ref Vector4 boneWeights)
{
Matrix bonesMatrix = new Matrix();
Vector4 bone0 = GetNormalizedBone(boneIndices[0]);
Vector4 bone1 = GetNormalizedBone(boneIndices[1]);
Vector4 bone2 = GetNormalizedBone(boneIndices[2]);
Vector4 bone3 = GetNormalizedBone(boneIndices[3]);
bonesMatrix.SetRow(0, bone0);
bonesMatrix.SetRow(1, bone1);
bonesMatrix.SetRow(2, bone2);
bonesMatrix.SetRow(3, bone3);
return Denormalize(Vector4.Transform(boneWeights, bonesMatrix), BoneRange);
}
// http://web.stanford.edu/class/cs248/pdf/class_13_skinning.pdf
private Matrix ComputeSkinning(Vector4UByte indices, ref VRageMath.Vector4 weights)
{
// TODO: Optmize
Matrix ret = new Matrix();
for (int it = 0; it < 4; it++)
{
float weight = weights[it];
if (weight == 0)
break;
// NOTE: m_skinTransforms are already transposed
Matrix transform;
Matrix.Transpose(ref m_skinTransforms[m_skeletonIndices[indices[it]]], out transform);
transform *= weight;
ret += transform;
}
return ret;
}