It seems USPTO allows shading but, for example, the Chinese's counterpart doesn't.
So what is the best way to do drawing internationally? I.e. if the application with shaded drawing is filed in the US first, then will it be accepted in China later? Or is it must be rewritten?
In case the drawing must be redrawn, is the priority date of the US application accepted?
I guess using a non shaded drawing is the best option to avoid the headache. But I still want to know, just in case it is needed.
Another problem is that, the type of shaded perspective view that is required by USPTO is not supported by CAD software. That type requires shading by line and dot, while most computer software fills the surface with color (see the image below). How the hell can I draw that type of drawing? It requires artistic skill and time consuming.
So what is the best way to draw shaded surface for patent application using computer?
What is the consequence, if I draw shaded surface using gray area (this method is supported by software)? Will this be considered color drawing and accepted by USPTO?