two polygons of same dimensions and one is stretching past edge, other is not

Can someone please help me. I have two faces I kade, one on the left of an object,
and one on the right. The one on the right is fine, the one on the left is bending around an edge.

I really need to understand what would cause this because they should be the same.


Moved from “General Forums > Blender and CG Discussions” to “Support > Modeling”

I can’t be sure it’s the cause, but both of the polygons are degenerate. That is to say, they have acute angles, which I try to avoid, and which could cause issues, unless someone has a better idea.

First off, I’m glad something got me to post on here because I’ve been meaning to for awhile. Thanks for moving my post to the correct section. CGCookie is awesome, and so is Blender. So I hope to frequent and learn a lot roaming around here and chatting with you all.

So if a quad is degenerate if it has any angle less than 90 degrees, how do you make objects from quads like that? With four angles, unless if all are exactly 90 (or you mean just the angle causing the (wish I even knew what to call it) extending polygon?), wouldn’t it be degenerate? I’m still a little fresh to terms like degenerate. Been using Blender for about 10 or 11 months now, but I seem to still have a lot to learn about specifics like this. Any advice you can give me would be awesome. I’m trying to model steps and a slanted side part of the steps and this is the bottom of the railing going up.

Btw, I found with length analysis on, that the lengths are not exactly the same but I thought they were with how I made it.

The left sides are 11.1, 15.7, 7.72cm, and the right is 10.5cm, 14.8cm, and 7.63 cm, and the angles on the left are 33.909, 59.996 degress. The right is 38.841 and 62.752 (For some reason mesh analysis only shows me the two outside angles, not the inner). I’m going to remake it and fiddle and see what happens. If anyone has some advice on how I should change my topology tactics up to avoid seeing this, it would be super appreciated.

First off, I’m glad I signed up for this site. I’ve been meaning to for sometime. CGCookie and Blender are great. I’ve been using Blender for almost a year. I checked the lengths and they weren’t exact so I made sure they are and now the right side is doing it but the left is not. I just moved the side so it wouldn’t bend like that.

How do you avoid using degenerates on quads if they can’t be under 90 degrees? That sounds mathematically impossible unless it was a square or rectangle. Do you know any videos or tutorials which would help me follow a process where I would be less likely to experience this issue?

I look forward to roaming these forums and learning Blender with everyone. This stuff is really great. I’m trying to make game assets to use in Unreal engine. Anyways, thanks for replying and for moving my post to the right section.

Take a bit of time for read well the links who have been posted by JA12… As it is a gold mine of informations.

Anyway if you want to fix it quickly, knife tools and divide thoses faces in 2 triangles should do the job…

Thank you, thank you, thank you. Those links are tremendous!

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