When to use double edge loops?
Greetings to all!
I'm kinda new to the whole subdivision modelling thing. I've spent a lot of time going through a ton of tutorials online and modelling up nearly every shape I consider interesting. I've also gone through the entire "model dem shapes" thread posted here, which thus far has been an amazing learning resource.
Anyways, I've noticed something when attempting to model hard surfaces. On occasion, I'll run into a situation where I've got a very thin edge loop bordering a very large polygon. When this gets subdivided, those edge loops tend to move around a lot (as one would expect). This seems to cause an imperfect bevel around those edges that varies depending on the distance the edge loop moves after subdivision. It's a very subtle artifact, you only tend to notice it with highly reflective materials or if the light hits the mesh just right.
My usual solution to this problem is to use two edge loops instead of one. The innermost edge loop is therefore the one that that moves the most, while the outermost edge loop basically sticks in place, creating a perfectly uniform round edge.
So I have a couple of questions:
1) Is my solution the correct solution to this issue? Or is there some better way of handling this problem?
2) If you have ever encountered this issue, did you bother fixing the problem or just chalk it up to the way subdivision modelling works and move on?
Cheerio!
-CMPX
I'm kinda new to the whole subdivision modelling thing. I've spent a lot of time going through a ton of tutorials online and modelling up nearly every shape I consider interesting. I've also gone through the entire "model dem shapes" thread posted here, which thus far has been an amazing learning resource.
Anyways, I've noticed something when attempting to model hard surfaces. On occasion, I'll run into a situation where I've got a very thin edge loop bordering a very large polygon. When this gets subdivided, those edge loops tend to move around a lot (as one would expect). This seems to cause an imperfect bevel around those edges that varies depending on the distance the edge loop moves after subdivision. It's a very subtle artifact, you only tend to notice it with highly reflective materials or if the light hits the mesh just right.
My usual solution to this problem is to use two edge loops instead of one. The innermost edge loop is therefore the one that that moves the most, while the outermost edge loop basically sticks in place, creating a perfectly uniform round edge.
So I have a couple of questions:
1) Is my solution the correct solution to this issue? Or is there some better way of handling this problem?
2) If you have ever encountered this issue, did you bother fixing the problem or just chalk it up to the way subdivision modelling works and move on?
Cheerio!
-CMPX
Replies
As you noticed, the more distance between edges the further they will move when subdivided. Generally double edge loops are a good idea; sometimes even more. You want the subdivision to be smooth / similar between shapes, so one loop won't do the same job on a small piece as it will a larger.
So really you use more loops when you notice your subdivision is uneven. Unless I'm mistaken it's a judgement you make when working rather than an exact science.