I imported a bgeo geometry and use a python node to write out each polygon's centroid position and normal. However, I got the error message that “Surface” object has no attribute “normal”.

What I don't understand is that I can see the normal lines when I turn on surface normal display. And the same python node works fine with other polygons created in Houdini.

May I ask how to get the normal back?

Thanks!

well, I found that the same model imported as obj file poses no problem to the use of my python node. So, I assume it's probably a .bgeo file format issue …

anyway, additional advices are appreciated!