// First pass: calculate the transofmration matrix for each vertex
// here we must associate a matrix with each bone (maybe with each vertex_id??)
// then we multiply the current_bone matrix with the one we had before
// (perhaps it was identity, perhaps it was already some matrix (if
// the bone influences many vertices) )
// then we store this multiplied matrix.
// in the render function we get a vertex_id, so we can find the matrix to apply
// to the vertex, then we send the vertex to OpenGL
public void RecursiveCalculateVertexTransform(Node nd, Matrix4x4 current)
{
Matrix4x4 current_node = current * nd.Transform;
foreach (int mesh_id in nd.MeshIndices)
{
Mesh cur_mesh = _scene._inner.Meshes[mesh_id];
MeshDraw mesh_draw = _mesh_id2mesh_draw[mesh_id];
foreach (Bone bone in cur_mesh.Bones)
{
// a bone transform is more than by what we need to trasnform the model
BoneNode armature_node = _scene.GetBoneNode(bone.Name);
Matrix4x4 bone_global_mat = armature_node.GlobTrans;
/// bind tells the original delta in global coord, so we can find current delta
Matrix4x4 bind = bone.OffsetMatrix;
Matrix4x4 delta_roto = bind * bone_global_mat;
Matrix4x4 current_bone = delta_roto * current_node;
foreach (var pair in bone.VertexWeights)
{
// Can apply bone weight here
mesh_draw._vertex_id2matrix[pair.VertexID] = current_bone;
}
}
}
foreach (Node child in nd.Children)
{
RecursiveCalculateVertexTransform(child, current_node);
}
}
/// <summary>
/// Function to blend from one keyframe to another.
/// </summary>
public void ChangeLocalFixedDataBlend(ActionState st)
{
Debug.Assert(0 <= st.KfBlend && st.KfBlend <= 1);
foreach (NodeAnimationChannel channel in _action.NodeAnimationChannels)
{
BoneNode bone_nd = _scene.GetBoneNode(channel.NodeName);
// now rotation
tk.Quaternion target_roto = tk.Quaternion.Identity;
if (channel.RotationKeyCount > st.TargetKeyframe)
{
target_roto = channel.RotationKeys[st.TargetKeyframe].Value.eToOpenTK();
}
tk.Quaternion start_frame_roto = channel.RotationKeys[st.OriginKeyframe].Value.eToOpenTK();
tk.Quaternion result_roto = tk.Quaternion.Slerp(start_frame_roto, target_roto, (float)st.KfBlend);
// now translation
tk.Vector3 target_trans = tk.Vector3.Zero;
if (channel.PositionKeyCount > st.TargetKeyframe)
{
target_trans = channel.PositionKeys[st.TargetKeyframe].Value.eToOpenTK();
}
tk.Vector3 cur_trans = channel.PositionKeys[st.OriginKeyframe].Value.eToOpenTK();
tk.Vector3 result_trans = cur_trans + tk.Vector3.Multiply(target_trans - cur_trans, (float)st.KfBlend);
// combine rotation and translation
tk.Matrix4 result = tk.Matrix4.CreateFromQuaternion(result_roto);
result.Row3.Xyz = result_trans;
bone_nd.LocTrans = result.eToAssimp();
}
}