Looking for opinions...

[Anonymous]

I was hoping some of the more experienced people here might help me out with what I did right and what I did wrong here and what you might do different. Basically it's vents in a fuselage and doesn't seem to complicated. I am kind of curious how much you might think the surface distortions might show up once it's textured...

Thanks in advance!

Kevin

[Steve_Curley]

Firstly - which max version? I know it's in the title bar in your image, but it's much better to put it in your signature along with your brief system specs. If you hadn't captured the title bar we couldn't tell.

Secondly - because I can't tell from the image - are you smoothing that? Either with a MeshSmooth/TurboSmooth or with NURMS inside the Editable Poly?

You have 2 problems which will cause those artifacts, and yes - they may well still be noticable even when textured.

"T" junctions - where one edge meets another but there's no edge the other side of the junction (top-left, just under the cockpit) are a bad idea (unless they are unavoidable where they surround a hole in the mesh). I'm guessing (the image isn't clear enough) that there will be lots of these around the vents.

Try to avoid polys with other than 4 sides (quads) - they don't smooth well at all. You can see from your own images that where you have triangles, or polys with 5 or more sides, they coincide with the "artifacts". If you turn off "Edges Only" in the Object Properties you will see the actual construction of each of those polys - rather messsy at a guess. Quads have only 1 "invisible" edge and they smooth well.

Low poly is good, but there's only so far you can go without losing quality - a trade-off, as always 😉

[Anonymous]

I tried a Meshsmooth modifier on it, but it tore the surrounding area up pretty bad, so I went back. Right now, I have smoothing groups set around 4, I think...

Kevin

[Steve_Curley]

Don't confuse Smoothing with Smoothing Groups - different things entirely.

Smoothing groups alter the normals of the existing polys so as to eliminate the hard edge between adjacent polys. Smoothing works by subdividing the mesh thus creating many more, smaller, polys.

Having 4 Smoothing Groups just means there are 4 areas of the object where within the group there are no hard edges, but between them there may be. Polys can belong to more than 1 group which may mask that behaviour.

If you have 4 iterations of Smoothing then you have one heck of a lot of polys. Turn on the Viewport Statistics to see just how many (with different numbers of iterations).

If adding MeshSmooth "tears up the model pretty bad" there are likely to be other problems as well. Try adding an STLCheck modifier and see what it says.

[Anonymous]

Thanks for the tips; this is very informative... 🙂 I was unfamiliar STLcheck until you mentioned it and it looks like a very useful tool. The results seem a bit inconsistent though. The first time I used it I came up with 113 errors, that jumped up to 143 for some reason, and then back down. After playing around for about 20 minutes, I got that down to 90 just on welding some vertices on the wingroots. Is that as huge a number as it sounds? I'm not sure where to go from here. I do see that some (most) of the problems are around where I cut out the vents and cockpit though so I'm certain that I screwed up somewhere doing that...




Here are the results...

[Steve_Curley]

The results are conspicuous by their absence...

If you're trying to attach the scene file (.max) you must zip it first.

[Steve_Curley]

Seems I beat you to it....

What I normally do with the STLCheck is to
De-Select the "Change Mat ID" option
Select Edges
Then go through the options at the top one after the other - makes it easier to see what type of error you're looking at.

[Anonymous]

No, I just posted the wrong screenie and I think you caught me while I was changing it... 😉

Kevin

[ekahennequet]

If you are trying to model this plane in its final resolution from start to finish, then you are asking for a lot of headache. Keep the poly count at a medium resolution and apply Meshsmooth to handle the high-resolution.

There are few caveats with Meshsmooth/Subdivision modeling:

Try to keep your polys in quads (4-sided polys) as much as possible when preparing your model for Meshsmooth. Don't worry if you end up with non-quads at some point. You always will. Just make sure to adjust them as you go. Each iteration of Meshsmooth will subdivide each poly by 4, which means your model's poly count will become heavy, so you need to be mindful of this as you model in low or medium res. However, many smoothing artifacts should go away unless you have extreme angles with very few polys between them.

The reason for the "tearing" around the holes after applying Meshsmooth is because you have not enough polys/edges around the holes. When you have open edges when modeling for sub-division, you'll need to add more rows of polys where the opening is so that it creates an anchor. I would close those hole during modeling and open them later. Also, your model has a lot of 5 to 6-sided polys. These polys, when subdivided with Meshsmooth, will create what may look like "tearing" or bunching and create messy lines. Try to make them 4-sided while keeping clean lines.

You always need to add more rows of polys around sharper angles, corners, and curves. Otherwise, applying Meshsmooth to the model will melt it. 🙂 For example, create a Box with 1 segment (1 is minimum) in Length, Width, and Height, then apply Meshsmooth. Your box will melt and look like a blob. Go back to your Box and increase the segments to 4. You should start seeing the shape of a box with smooth edges.

The trick is to model in as low resoultion as possible without losing the integrity of the model when Meshsmooth is applied.

AREA has some basic Poly modeling tutorials that you may find useful. I'll try to dig up some links and examples for you.