#4866 V texture coordinate inversion on OBJ loadModel

[myselfhimself]

Testing this as WebGL requires a flipped/inverted V texture coordinate

this is untested for now, unsure it resolves something

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[myselfhimself]

Tested, see #4866 (comment)
This copies Processing's UV's V dimension inverting behaviour on OBJ model loading. It seems this inverting had been forgotten in the p5.js implementation so far.

[myselfhimself]

This could mergeable with some note to be added in a changelog and maybe a note on UV interpretation in the documentation...
Flipping the V dimension (because Y is flipped in WebGL or so), still does not solve all OBJ UV mapping issues, with sometimes images being flipped horizontally and/or vertically without plainly understanding why... If strict following for p5js of the Processing behaviour and API were not a must, maybe some helper flags or functions could allow developers to flip those coordinates easily. Eg. on loadModel(, , flipU boolean, flipV boolean)..

[stalgiag]

@myselfhimself Thank you so much! I really like the idea of adding flipU and flipV. Perhaps they could be overload parameters in loadModel? We don't have any limitations as far as following Processing and I think this could be useful for quick fixes without needing to reexport model files. That can be discussed in another issue if you would like.

@all-contributors please add @myselfhimself for code

[allcontributors]

@stalgiag

I've put up a pull request to add @myselfhimself! 🎉