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nour
08-07-2005, 08:59 AM
Probably this question has been asked several times before but I don’t know what this ”problem” is called and I tried to search here but I couldn’t find anything

However, I have used smooth shift but I left with hard edges

How to solve this problem?

thanks

Hoopti
08-07-2005, 06:41 PM
Looks like you have some poly overlap. You may want to post a wireframe to be sure, but it looks like that. Either that, or those aren't subpatched. Open the numeric panel and make sure the number of polys equal the number of subpatched polys.

Those are the two issues I can think of.

Hoop

Surrealist.
08-07-2005, 09:37 PM
It could also be a 6 polly point - a point that shares six pollys. Depending on where you smoth shifted from this would be easy to do.

If that is the case you may be able to solve it with a little spin quad action. Looks to me like it could be an overlapping poly too or both.

Post a wire. :)

nour
08-08-2005, 06:00 AM
yeah,,,when I unweld I get 6 points...

I have used spin quad but it seems it moves the hard edge elsewhere

Krom
08-08-2005, 07:28 AM
Try freezing NURBS mesh and see if problem remains.

Surrealist.
08-08-2005, 11:38 AM
yeah,,,when I unweld I get 6 points...

I have used spin quad but it seems it moves the hard edge elsewhere

The solution here is to simply redesign your polyflow around the corner of the mouth. Sometems spin quad can me a quick fix. However, adding more geometry is the only way sometimes. The corner of the mouth should have a quad. That would be the most stable.

Please pardon my unartistic and overly simple examples:

Picture 1 & 2 Is a better poly flow but not the best in my opinion. There is no edge loop around the mouth area and there is a 5 polly point on what I call a "high stress area."

Think of edges as rubber bands holding back a balloon that is trying to expand when you are in subpatch. Anything that is not a quad has the potential to give you probmlems in giving you the shape you need - or even render errors. Triangles are legal, yes, but they will give you render errors in high stress areas.

The same goes for 5 and 6 polly points. In flat areas you can even get away with 6 or more, or tiangles. The more curved the higher the stress. The highest stress areas are in places where the curves are sharp.

Pictures 3 and 4 are a simple example of using edge loops of quads and 4 polly point vertexes on a sharply curved area. I just made a wedge with the wedge tool to show the polly flow then used badsaw pro and sqashed it and pulled some points around to show how this polly flow makes a much more stable high stress curve such as the corner of the mouth.

You can use this info and modeling tools to correct your model. Hope this helps. :)

nour
08-09-2005, 04:14 AM
Thank you Surrealist.

that was great help, I really appreciate it

don't you think you should start having your own video learning? :thumbsup:

thanks again

Surrealist.
08-09-2005, 01:09 PM
Thank you Surrealist.

that was great help, I really appreciate it

don't you think you should start having your own video learning? :thumbsup:

thanks again


Thanks, you are too kind. Already many out there doing a great job. I am just a learner like you, I get a lot out of being able to show others what I know or have found out, as it helps me learn. But thanks for the compliment just the same. :)

mabaza
08-12-2005, 09:48 AM
I'm so glad this thread got created because I have never been able to find a good solution to the problem in which a vertex is shared by more than 4 polys.

Surrealist. Can I ask exactly how you rebuilt the poly flow to go from picture 1 to picture 3? Thanks!!!

:lwicon:

Surrealist.
08-12-2005, 12:48 PM
I'm so glad this thread got created because I have never been able to find a good solution to the problem in which a vertex is shared by more than 4 polys.

Surrealist. Can I ask exactly how you rebuilt the poly flow to go from picture 1 to picture 3? Thanks!!!

:lwicon:

Sorry but I cheeted just for the purpose of illustration/time so I actually did not rebuild it. I had just squished the wedge down to illustrate the concept. I was going to rebuild it but that would have taken a while just to answer the thread and I had no more examples at hand to show it. But now I do.

But first, to answer your question here's how I would have rebuilt it, as it looks like I'm not getting off the hook that easy :)

Method A is the spin quad method. I think of spin quad as a part of a very specific modeling technique. As you can see, spining the polys around starts to redirect the poly flow. If you have a clear vision of what you want to get and you want to stay in subpatch the whole way and are very patient and are looking to merge a lot of polys to get a low poly mesh that has step down from high to low poly areas, then this is the method to use. Of course, as I say that there are certainly other uses for spinquad and it is not an absolute rule by far but it is part of a very specific technique, is the point.

Bethod B seems a little more tedious, but is far more logical and actually takes less time and headache - to me. But it has the draw back of rendering a model with more polys.

You sart out with the Add Edges tool (Detail/edges/Add Edges) and connect the little blue circles (not shown) by dgagging on them to create the lines shown in the first picture. Make sure and bring the circles-which represent points- to full 100% and full 0% when dragging them to a vertice so as to not have too points close to each other. You want it merged with the vertice.

You then merge the polys to get the second picture. Then you have to delete the other half and mirror. You can then subpatch and add more lines to the edge loop if you want with bandsaw pro.

This leads me to what I have been leaning towards lately. Planning out your poly flow in advance.

Here is the link on this site that shows a continuation of this process and what it was for:

http://vbulletin.newtek.com/showthread.php?t=39449

More information here at the end of the thread:

http://www.spinquad.com/forums/showthread.php?t=7503

Now in the end I wound up with a boatload of Pollys but it is a WIP as a technique.

Surrealist.
08-12-2005, 01:55 PM
Here's just a little more info I coppied from another thread where I outlined some modeler tools and the concept of the 5 poly point and edge loops. This might also help. :)


I consider all these tools in the same class:

Smooth Shift
SupperShift
Extender Plus
Bevel
Cut

Now yes most of those are in the extend group anyway and cut is not.

(Extrude is not in this class because it can cause problems in subatch. You have to delete the base poly and merge points. Otherwise it would be the same in essence as I describe below)

The reason I consider these all as one class is becase they all create the same kind of geometry. Hold your haunches, let me finish. That is they will take a selection and create new geometry with five polly points at the corners and leave you with an edge loop. If you perform this twice you have one clean edge loop.

Hold on, not done yet...

Edge loops are important to the polly flow of the shape of course but also to creating detail especially around places such as the mouth and eyes where you want to continue to add loops to create ridges such as the eyelids. There are of course many many uses for this.

The technique of using suppershift over and over to pull out a convex shape or pull in a concave or to create ridged edges etc. is really just a technique that is creating a new series of edgeloops within a mesh that are surounded by 5 poly points. The key here is to get your edited mesh - if possible - away from those 5 poly points. Certainly not always possible or completely necessary but the point is that it creates edgeloops. This is where bandsaw pro comes in as one of it's uses.

OK

Now of course there is a difference between how Bevel treats the selection. This sets it appart from Cut, Supper Shift, Smooth Shift, Extender plus, which all allow you to select more than one poly and create the edgloops around multiple polys whereas bevel only alows edgeloops around one poly at a time no matter how many are selected.

Then there are differences between suppershift and smooth shift as far as interactivity but beyond that they are the same. Extender Plus allows you to have a tool such as move or size active and continue hitting e to create new segments or loops.

Cut is set apart again only becase it a) actually subdivides - calulates the center of the selection whereas the other tools put geometry right on top of the selection and b) it is customizeable in that you can have it subdivide in ways that cut the mesh differently in the corners etc. In its default setting however, it gives you the same geometry as all the other tools with the exception that it actually divides.

OK alot here but the point here is understanding whst these tools do with the geometry. Thier use then depends on the situation and of course the preference of the user.

mabaza
08-12-2005, 02:31 PM
Surrealist,

I can't tell you how tremendously helpful your comments are! :bowdown: As this thread demonstrates, even if your mesh is all quads, you can still get rendering errors with LW's current SDS implementation. I've been driving myself crazy trying to figure out how to overcome this exact problem, but have no luck...yet!

I found this part particularly interesting since I use supershift alot
================================================== =====
The technique of using suppershift over and over to pull out a convex shape or pull in a concave or to create ridged edges etc. is really just a technique that is creating a new series of edgeloops within a mesh that are surounded by 5 poly points. The key here is to get your edited mesh - if possible - away from those 5 poly points. Certainly not always possible or completely necessary but the point is that it creates edgeloops. This is where bandsaw pro comes in as one of it's uses.
================================================== =====

Are you saying its better not to use supershift to create new geometry since you are guaranteed to have 5 polys vertices? Or are you saying, use supershift but then clean up your mesh to get rid of these 5 poly vertices?

Thanks again for all your very valuable insight! :lightwave

Surrealist.
08-12-2005, 05:58 PM
Hey Mitch,

Well, actually I am probably just pointing out the obvious, more or less, that this is the geometry that is created.

In Open GL you see many more render errors than you see in an actual render. The problem I have with 5 poly points is thier placement. By necessity they are usually at a point where the shape changes or where the polyfow changes.

Anytime you go from one flow to another you are going to get a 5 poly point. Unavoidable.

What I have been trying to do lately is direct where they are so that they do not wind up in an area near where I have a critical edit and I am learning about this on a day by day basis.

I tried a mesh - as you may have scene on my head primitives thread -that was as many grid connections as I could have with as less 5 poly points as I could muster. However this kind of a mesh is not without problems and I am currently redesigning my mesh accordingly.

Pic 1) Basic poly flow of the head. Note where the 5 poly points come at the transitions between the edgeloops. Also note that I made sure and kept the 5 poly point above the jaw so that there would be a clean jaw line. This is what I mean by keeping it away from the edit. Otherwise you get a bump that wont go away and even a possible render error.

Pic 2) My high mesh object. Note how there is little in the way of 5 poly points. However, the poly count is too high and some of the poly flow makes it hard to edit certain parts of the mesh.

Pic 3 and 4) lately I have found a comprimize and another interesting rule of thumb. The density of the mesh. Here's the two fold rule A) The less mesh, the more tension on the points. B) the more mesh the less tension on the points. It is this point tension that causes open GL errors and and possible render errors and dispite either, a heck of a time getting the shape you want.

So the balance is getting a mesh dense enough to burry the filve poly points while still keeping the poly flow correct and the poly count resonable.

However, for every rule there is an exeption. There are those who use 5 poly points in critical places all the time. It is just that each situation is completely different. You have to use your judgement.


For very simple cartoon models you can get away with very little polys. The more realistic or expressive the face the more need for a higher mesh. I am just now experimenting with this. I'll be posting an updated mesh on my other thread when it is done later today.

Surrealist.
08-12-2005, 08:22 PM
A couple of pics showing updates on my head to correct for a better polyflow. I managed to remove some of the meash too.

here's a great tutorial that explains some stuff I have been talking about on this forum:http://www.newtek.com/products/lightwave/tutorials/modeling/various/index.html