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Meowx

Mesh deforming - how do I keep it smooth?

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Typically, the initial mesh I plot out looks just fine. Of course, I have to move it around to get it looking right, and once I do, crinkles and creases start showing up from some angles - even though the splines look perfectly smooth. How do I fix/avoid this?

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Animation_MasterScreenSnapz008.jpg

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Is this an original model? Or are you modifying an existing model done by someone else? If this is your model done from scratch you have a great start. If you are a new user of AM you are way ahead of the learning curve.

 

There is no "magic" solution for smoothing the mesh. You have to view the mesh from many angles and tweak the points till the mesh looks smooth. I often look for a "bump" or crease, select a point in the trouble area and rotate the view so I am looking "down" along that spline at a very steep or low angle so I can see all the bumps and wiggles along the spline that aren't as visible when looking at it straight on. Then you use the arrow keys to nudge the points this way and that way to smooth it out. Sometimes if you have problem areas like 3 point and 5 point patches this is not easy. You may see or discover a better way for the splines and points to be connected and have to break the mesh and reconnect to smooth things out.

 

This process is very much like sculpting with clay. It's part of the learning process. After awhile you feel this thing in your brain that sort of goes "ping!". Suddenly you just... feel it. You start to get use to the process and it becomes easier. It takes practice. I can still remember that moment. It's a real moment. It's when you smooth out a series of nasty bumps on a model, the splines flow smoothly the mesh looks smooth and it felt almost "easy" getting there.

 

How long did it take you to get to this point? How long have you been using AM? Keep practicing. Try not to get frustrated or discouraged. This isn't going to happen "overnight" but if you persist it will come to you.

 

-vern

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She's looking good!

 

One of the first things I would check would be your Normals.

Have you checked those to see if any are pointing inwards?

 

As something of a follow up to what Vern said...

If you have an area that is particularly problematic you may want to delete that area and reconnect the splines again. If the splines aren't continuous or go a direction you weren't aware of this will allow you to correct it.

 

Where possible let A:M correct it.

One way to get a smoother mesh might be to use the Y key to get a CP created right in the middle of a spline versus the angle/orientation you may have moved it to manually. Then connect your other spline to that CP in the middle of the spline. (Try holding down the Shift Key as you connect the CPs to maintain curvature of the spline) Keeping patches roughly the same size may be of extra benefit when you go to decal the mesh later.

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I think vern left out one key word... Bias adjustment... well, that's two. Those lumps can be fixed by slightly adjusting the bias of the CP.

 

You can adjust it manually with the yellow handles, but it's actually easier to do fine adjustments in the properties box. Select the CP and you can drag on the number in the properties to change it in 1° increments. It's almost always the gamma that you adjust, rarely the alpha.

 

Someone will probably pop in to say adjusting bias is bad for animation, but that hasn't been true for several years.

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Thanks for the quick replies!

 

I started using Hash back in 2000, but I haven't really touched it since 2005 (been doing 2d and comp work). Now I've got a couple projects I want to finish; this is an original model and will be the first one I've ever given a full rig with constraints, dynamics, and smartskins. (Here's some of my older work in Hash; pretty basic rigs involved.)

 

Oddly enough, almost the entire head had its normals facing inward! That helped a bit.

 

Found a decent angle to start pushing out some straight lines; one other question. Is the 5 point in the 2nd picture going to cause problems when I start doing a facial rig?

 

edit: wow, adjusting the gamma is actually helping quite a bit.

Animation_MasterScreenSnapz009.jpg

Animation_MasterScreenSnapz010.jpg

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All right, new problem. The face has been shaping up nicely, but I've also been adding in more detail as the original was just a rough draft.

However, as I'm adding some definition to the shape of the lips, I keep getting creases at the corners of the mouth. I'm not having much luck fixing this. Any recommended geometry changes or suggestions?

Thanks again!

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The "crease" is really just the shape your CPs are making.

 

When you have some CPs VERY close together they will do their job and try to make very tight shapes. My first guess is that the middle CP of a group of three is making a small peak or valley.

 

here's a simplified example:

 

CPCreases.jpg

 

 

model:

 

CPCreases.zip

 

(JPG banding may make this look less smooth)

 

 

you can make small CP adjustments easier with 4 5 and 6 keys

 

4 constrains CP to direction of spline

5 constrains CP to perpendicular to direction of spline but still along patch surface

6 constrains CP to perpendicular to patch surface

 

 

Another possibility is that you have some spline continuity mistake, but you seem be doing well at that so I doubt that's the problem here.

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My other thought is... do you really need 3 CPs at the corner of the mouth when you can make the same shape with 2 or 1 CPs?

 

321corner.jpg

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Hmm ok. Thing is, I can't really find much to play around with in terms of valleys.

 

The CP in the first screenshot used to be a hook, at that point there was no crease. If nothing else, I can just go back to the hook, but having it as a CP does make quite a difference in the lip shape. (Crease looks fine from front angle, see 3rd shot for rotated version.)

 

Would it help you if I uploaded the face as a model for you to better look at?

Animation_MasterScreenSnapz016.jpg

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Animation_MasterScreenSnapz017.jpg

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After looking at the last generation's mesh and pushing CPs around without the wireframe showing I got it un-creased again. Thanks again, this is one of the most helpful communities I've come across!

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