Modeling : nGons, good or bad ?

[ToddD]

Polys with more that 4 side are ngons. 5 sided you can get away with sometimes, but as soon as you go higher, you are likely going to encounter shading errors. Shading errors look like dark areas, and are not good. You also want to look out for vertices with more than 4 edges intersecting. Look at the poast theoretical sub-d for more helpful info on this type of thing. Hope this helped:beer:

[aor]

how do you make these? can you use curves as sides? if so, then great, cause that sounds exactly like what i need... see my post that should be close to this one:surprised

thanks!:beer:


:bounce: :bounce: :bounce:

[ToddD]

Aor I think you are making spline patches(splines/surface modifier), that is different than creating polys. Not sure if my post was clear, but a many sided polygons could lead to trouble in your surfaces when meshsmoothed and should probably be avoided.;)

[RealThing]

Actually the problem isn't really with shading. On a more or less co-planar face n-gons are fine. But there are 3 things that will get you in trouble using them. Attempting to use them as a non-planar face which can result in shading defects....some which can be avoided by changing the tesselation. Secondly if you're using meshsmooth you may end up with some artifacts depending on the topography of your mesh. But lastly and most importantly if you plan on animating the mesh avoid using anything higher than 4 sided poly's. The mesh even though it's represented to you as a n-gon still has to be triangulated for rendering and when animated you can get unwanted creases and such going on in the mesh. This is even more important if hair is involved. So whether you should avoid using them or not really depends on the situation and there are many situations where they are handy. You just have to know when to avoid them.

[aor]

interesting.. thanks for the info!

[ToddD]

It's all pretty much covered in the Theoretical SubD post. Shading is an issue I would not dismiss. Unless your surface is flat, when smoothed you will run into problems. I don't model characters, but yes I can see creasing being an issue when animating. For Aor's application, a car model, I would say he could get away with 5 sided as long as the area is not dramatically curved, or an area where the mesh has transition from a curve to a flat surface. I would always worry about the resulting poles(vertices that stop the meshes flow) that sometimes result from the multi sided polys more than the polys themselves
:D

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