Limitations with U3D (PDF 3D) animations with thick materials and curved creases.
Answer
Animation transformation capability
The U3D libraries do not allow for the transformations to deform geometry for animations of curved creases and bends. It also does not allow for the proper folding of thick material.
This means for these types of designs, the U3D model in PDF may not be as accurate as depicted in ArtiosCAD.
U3D is composed of triangulated surface geometry meshes. When a design folds in U3D, U3D provides no transformation that the panels bounded by the crease, can stretch. The crease just bends along its axis.
U3D animation
ArtiosCAD animation
ArtiosCAD knows the fold will stretch and will accommodate the view of the thicker material.
Side effect
A side effect is that the thickness of a panel that starts at 180 degrees and is fold onto itself at 0 degrees, will not be correct in a U3D animation.