While some may paint or draw pornography, I disagree that nude art should be considered as a form of porn.
I took life drawing classes - and found them completely asexual - One of the models at the time was a young lady I was sleeping with - and seeing her naked in front of the class was as asexual as anything you could imagine. Funny thing - it's all contextual - if I'd taken her to an event and displayed her naked it would have been extremely sexual in nature - but in a life-drawing class? nope - just the reverse.
And I wouldn't class anything that was produced in that class as overtly pornographic in any way