The 'Dents and Bumps' thread.

[Sonnu]

Hi Fellas!

We all face the horrible nightmare of dents and bumps on the surface of the mesh while modeling our favorite cars. Sometimes we are able to resolve it, but most of the times we have to resort to render tricks to hide the ugliness, although it shows up to some extent anyway when light is reflected off the part at some angles.

The purpose of starting this thread is simple. Post your 'dented' part over here, and I, or some other kind soul will have a look at it and find a possible solution to remove, or at-least reduce the severeness of that part to the extent that it's negligible to the human eye. To help accomplish this task, we will also try to use the 'point light' method to double-check the problematic part. This is regarding just polygonal models, for now. I recommend this thread be sticky-ed for obvious reasons.

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But before you start posting your problems, please adhere to these simple guidelines so we can help out better.

1. As scooter79rs said, please post a proper wireframe and a render close-up of the problematic part to weed out topology problems.
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2. Concentrate on the problem part only, and that too if it is absolutely out of your hands to solve it. Comments are always provided in the WIP threads that you make. So please don't post every nit-bit that you encounter in your model.
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3. If verbal explanation is not sufficient for some reason, you might detach the problem part in question as a clone, and then post it as a file in whatever format your software saves in (and preferably in .OBJ format, too for other applications). That way, we can open that file at our place, work on that part and see what's wrong or find solutions quickly. This is only if nothing suggested by any other member works. Also, do not forget to mention the version of the software you are using!
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4. As a general guideline for high poly models, start the model as a low poly, adding edge loops wherever necessary only. Keep the low poly base model smooth with enough polygon density so that only minor tweaking is required to solve problem areas. Thanks to Nighteye for this one. But of course, client requirements may vary, and a different approach might be required.

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Also, we will try and put up tutorials of modeling really hard parts as and when time permits us, so that we can have a handy reference to the most common problems and their solutions. This will help with the workflow of many people. Hopefully.

Last but not the least, don't be afraid. Nobody will curse you for running into topology problems. These things cause headaches to even the most professional people, and they solve the problems by asking around too. So go ahead and start posting your dents and bumps!

Cheers,
Sonnu.

[scooter79rs]

Seems like a good idea, I would have personally posted this in General Discussion not 3ds Max as bumps in the model is to do with mesh topology not the program thats used to create.
Because a 'dent' or bump can happen in any program, I would say it should be mandatory to post wires with a render so people are able to actually comment on the topology that could fix or at least reduce the severeness of the bump.

[The IC]

sounds like a good idea...might actually be worth putting this one in the WIP thread with a sticky, since thats where most people seem to go...maybe we could have one about normals in the low-poly area too

and as scooter79rs said, wed need to put simple guidelines so that people post enough information for other people to help

[Sonnu]

Agreed. I forgot I only work with 3ds Max and no other software. But if we can generalize this for other software too, I have got no qualms about that. Thanks for noticing guys! And I'll also update the first post about normals in low poly, although I thought it would be a better thing if the low poly and high poly threads are kept separate. So please decide on that and let me know. I have put up some basic guidelines, feel free to add you find missing or worth posting.

I kindly request Mods to move the thread to the appropriate section.

Cheers,
Sonnu.

[RedStar]

Also, all bumps can be gotten rid of, just know your topology and that should do it. And it doesn't matter what software you use, poly modeling is poly modeling.
Also, moved the thread to proper placement and a redirection will be left for 1 week.
Also stickied the thread, if any other admin feels it is not necessary please remove it.

[NightEye]

Originally Posted by Sonnu [/B] 4. As a general guideline for high poly models, keep the models as low poly as possible and let the Meshsmooth / turbosmooth / Smoothproxy etcetera do the maximum interpolation work. This will ensure that the bump or dent can be resolved quickly without resorting to major vertex level editing. [/LEFT] [/INDENT]

I can't agree on this one, though. Meshsmooth/SubDivision/etc isn't made to make smooth panels for you. It's made to make your smooth panels even smoother.
It's correct that you shouldn't use too many polygons, since that might get in your way when you're trying to smooth out an area.
Start lowpoly, and adding poly rows in places the mesh needs them. If your low poly model is smooth, only minor tweaking is needed to keep it that way.

[Sonnu]

Thanks for moving the thread and the sticky, Redeye. I also corrected the first post regarding the software, and added a guideline regarding the attachment of files from related software.

I can't agree on this one, though. Meshsmooth/SubDivision/etc isn't made to make smooth panels for you. It's made to make your smooth panels even smoother.

Well some clients have a requirement of ultra low poly base with 2 or 3 iterations of smooth. And I agree that having a properly subdivided base mesh eases the stress on the smoothing process. But more than 3 edge loops crisscrossing on a curvature on both axes is a nightmare to resolve, and although not impossible, it certainly increases the time taken for corrections.

It's correct that you shouldn't use too many polygons, since that might get in your way when you're trying to smooth out an area.

That was exactly what I was trying to point out

Start lowpoly, and adding poly rows in places the mesh needs them. If your low poly model is smooth, only minor tweaking is needed to keep it that way.

And that pretty much sums it all. Thanks for pointing it out. I have modified the general guideline accordingly.

Cheers,
Sonnu.

[NightEye]

I think that's much better Especially with the last sentence.
Thanks.

[Lynx]

ive run into a problem with a certain spot. I just cant get this to flow or look right. Ive circled the problem spot on the wire.

I attached 3 pictures: A smoothed, A wire and a closeup of the problem spot. If anyone can suggest something to help me out that would be awesome.

[NightEye]

I think I wouldn't have done it the way I showed in the picture, since LW can smooth tri's without any problems. But for Max, I think this will work better, all quads.

[Sonnu]

It looks like you did an extrude of some edge with height zero and tiny base width for a sharp edge there.

Get rid of the marked red edges. This is where the extra loops become unmanageable. Insert the edge loops only where necessary. Usually one edge loop on the inner side does the trick, and its distance from the end determines the sharpness of the Chamfer or Extrude. But if you absolutely want those loops, I'd recommend spreading all three loops out at their respective ends, so that the smooth modifier stretches them evenly and gets rid of the crease. Also, if you are comfortable with a few pentagons in your mesh, complete only one of the marked loops. Leave the ends of other two open at a place where meshsmooth will merge them with neigbouring polygon corners.

If you could post the max file of the bumper part in view detached from the whole mesh, I might be able to better illustrate what I meant.

[Lynx]

I got it fixed to the point whee I like it. Thanks for the suggestions, I guess I kinda used both ideas, haha, seems to have worked ok, there is still a small pinch but I can deal with it at the moment.

[eddybrown]

I'm having a small problem making a wheel for my elise, I'm getting a pinching in the corner of the spoke where it meets the rest of the wheel. I've tried alsorts to get rid of it and I've not managed it so I thought I'd post up on here.

[NightEye]

'Move' that tri someplace where you can't see it or where it can't mess things up. Perhaps this poly setup works:

[eddybrown]

Thanks for the quick reply NightEye, I ended up fixing it by chamfering one of the edges in the spoke and turning that tri into a square. This helps hide the problem into a tiny space, it's still there but I think it's hidden enough

[RedStar]

Eddy, I have a layout I designed which works perfectly for rim modeling. This way you dont actually need to weld anything. Check it out, maybe you can use it as well.

http://www.smcars.net/forums/tutoria...eling-rim.html

[eddybrown]

Thanks for the tut, I used a similar technique where I used the symmetry modify and then created an instanced array 360 degrees and used a spline as a guide so everything was round. The only bit I found hard was where the spokes join the rim and where the spokes join the centre of the wheel. I could have got around the problem by making the spokes fully 3d like they were formed from metal and then welded the joints properly.

[Sonnu]

I have seen that most of the times a low poly chamfer is the source of all the problems related with that setup...that's why I use supporting edge loops around the main shape edges where the sharp creases exist. Once you have the basic setup ready, you can just go on adding loops close to the original edges while testing the curvature of the meshsmooth chamfer end result. Almost always, one edge loop on either side does the trick.

Anyway, here's a tip for roundness...instead of using a spline and approximating where the diagonal vertices inline will lie, use a cylinder of the same sides as the low poly rim uses. That way you can snap your way to perfect roundness.

Attached are screenshots of a Merc rim I made for a specific client. Notice the inner edge loops. Also, I have attached a side view for low poly reference. This setup contains pentagons but the edge ends are adjusted in such a way that Meshsmooth doesn't have any problem wih the interpolating on either sides of the ends, and it makes the end result as quads anyway. If you want an all quad rim with zero triangles low poly version, this is not for you, although I'll dig up something I made earlier if somebody requests it.

Cheers,
Sonnu.

[Krystian]

I just don't have idea how to solve these problems. Tried everything I know and still nothing. Any tips?

[rcat]

I think you need some closer images to see the bumps around the door. For the back arch problem , I dont think you need this edge at all. If you delete it , it makes a quad which usually works for me.