When is a good reason to use the crease settings in the "N Panel" (I forget it's actual name) over adding more edge loops?
In this video https://cgcookie.com/lessons/connecting-the-arms @24:00ish Jonathan is using creases to sharpen up areas in the armpit.
From what I gather, are creases used for reasons instead of adding edge loops that would create unnecessary geometry? - Particularly in areas that aren't going to be scrutinised? Could a crease be used when adding an edge loop would otherwise create ngons?
Additionally, is there a 'rule of thumb' of sorts when adding creases to specific edges? As in, do you need to add creases to joining edges to add support? EG @24.50, Jonathan is creasing the edges on the X-axis, but also creases the diagonal one joining it.
I'm not at my computer atm to exercise it at the mo' - this is just a thought I had while working earlier
Cheers!
You are correct Harris, you would use crease when adding edge loops creates not only unnecessary geometry, but when it makes crazy long cuts that you don't need to be going all around your model. And correct again that since creases don't make for the best results, it's better to use them sparingly, in areas that are mostly hidden or just aren't going to be noticed so much. But just because your loops is going to create an Ngon is not reason enough to go with creasing in my opinion, just fix your geometry to get rid of the Ngon. And the only rule of thumb I can think of for crease is just that since they make the edge kinda muddy, you have to use them in areas that are not going to be seen too much.
Go back to 24.10 and listen. He explains that the Loops would cause problems unless you go through and alter the geometry. Creasing isn't as intuitive as edge loops and can create some ugly results. Now to answer some of your question:
1. When to use? in most cases, it's a matter of personal preferences. There are some cases like in the video where Edge loops creates ugly results unless you go in and adjust the geometry. Creasing can also be used to reduce geometry. Side note:In this case we are talking about edge creasing. In some cases to get good looking results you need to use vertex creasing or a combination of both. Vertex creasing was added to blender in 3.2 I believe. He is using 2.93 in the video.
2. Creating edge loops won't create n-gons or trigons(Triangles). Basically supporting loops and creasing are 2 methods of sharping edges when using subsurf modifier. In some cases one will give better results then the other. In most cases either one will work fine.
3. Unfortunately there is no rule of thumb. It comes down to experimenting and seeing which gives you the best results. As you gain experience, you will develop an eye for when to use one over the other.(So I've been told. I haven't developed this. So I guess I don't have enough experience yet, but then again I mainly do rigging and TD work in Blender)