Using TurboSmooth with Attached Objects

[t_smith5]

I've noticed a couple of glitches on a shoe model I'm finishing up the texturing for, and I'm wondering if it's related to attaching multiple objects together and then applying a TurboSmooth. Is this considered bad practise...?

With or without attaching objects together, I keep getting this weird glitch and I'm not sure why or how to fix it. With TurboSmooth off, it looks fine.

Once it's switched on, and/or I use Show End Result, this happens with some of the shoe lace holes...

It's confusing because some of them are perfectly fine, and the topology is exactly the same. Adding some additional loops cleans them up, but it still doesn't explain why some are perfectly fine without. I've tried adjusting the lattice from the Show End Result, but positioning it around doesn't seem to make it better. All of this is due to having Smoothing Groups checked under TurboSmooth. Switching it off makes them circular and more natural, but I was still wondering if someone could shed some light on why this is happening...? And if it's good/bad practise to attach objects and apply a TurboSmooth?

[10DSpace · Accepted solution]

@t_smith5 

When you attach objects, you need to weld the verts where the objects join for turbosmooth to work properly.  Otherwise turbosmooth will affect the separate joined parts differently.  From your image, it looks like there are places where the verts of the previously separate objects were not welded together. 

I'm wondering if it's related to attaching multiple objects together and then applying a TurboSmooth. Is this considered bad practise...?

No, it's not bad practice at all and is done all the time.  But as explained above you have to make sure that you weld the previously separate parts together so that turbosmooth sees the object a single unambiguous surface with no unwelded vertices. 

[t_smith5]

Okay. This was done as part of an exercise book I'm following. I think it said the two parts were to be separated, but it can be vague. It certainly didn't mention anything about having to weld them together again though. I'll just have to be more mindful in future when I attach objects without welding them. Thanks.