protected void WritePoseKeyframe( BinaryWriter writer, VertexPoseKeyFrame keyFrame )
{
long start_offset = writer.Seek( 0, SeekOrigin.Current );
WriteChunk( writer, MeshChunkID.AnimationPoseKeyframe, 0 );
WriteFloat( writer, keyFrame.Time );
foreach ( PoseRef poseRef in keyFrame.PoseRefs )
WriteAnimationPoseRef( writer, poseRef );
long end_offset = writer.Seek( 0, SeekOrigin.Current );
writer.Seek( (int)start_offset, SeekOrigin.Begin );
WriteChunk( writer, MeshChunkID.AnimationPoseKeyframe, (int)( end_offset - start_offset ) );
writer.Seek( (int)end_offset, SeekOrigin.Begin );
}