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mabaza
08-24-2005, 06:21 PM
When working with a SDS object, I use bandsaw a lot to tighten up edges. The problem is I only want to tighten up certain parts of the mesh, but using bandsaw tightens up the entire edge loop. How do I harden up only local geometry without introducing tris or n-gons?

On a related note, if I need to add geometry to my mesh, I run into the same problem. Namely, that the entire edge loop to which I applied bandsaw get "harder" thus throwing off the flow of my object...

Thanks gang! :lwicon:

Surrealist.
08-24-2005, 07:59 PM
Hi, I don't use this much or at all actually, but there is a subpatch weight. Do you ever use this?

You can paint it on with the airbrush tool

But as to your problem it is really a case by case basis. I usually try and separate the mesh as much as possible in areas where I want a smoother edge. Another helper is the smooth tool. Again a case by case basis.

Lets see, what else. Well planning. If you plan things in advance as much as poosible that can help.


Then in some cases it is possible to step down the mesh using this technique: http://www.newtek.com/products/lightwave/tutorials/modeling/4pointtriangles/index.html

Beyond that there is just careful massaging of the points in to bring in smoothing areas and sharper areas.

Also check out this thread for some sud ideas:

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

Also if you post a pick of specific prob, I'd be glad to offer some suggestions.

telamon
08-25-2005, 06:23 AM
an option is to change the polygon flow upstream and downstream the area you want to tighten. Spinquad is the tool for that. Then apply bandsaw and regenate the needed polygon flow with spinquad.

Dodgy
08-25-2005, 08:16 AM
Or select the points along the edge you want to tighten and use edgebevel (ctrl-b)

hrgiger
08-25-2005, 08:52 AM
Subpatch weight isn't edge weighting and is all but useless (IMHO). Subpatch weight is fine if you're tuning the curvature of the overall model which results from the subpatch but for local areas, it's crap.

Try this. Pick the area you want to bandsaw. Select the two polygons on either side of that area and delete them. This will prevent the bandsaw from continuing. Bandsaw the area between the two recently deleted polys. Now just go in and manually make a 3 point poly and a 4 point poly where you deleted them. If you're really against tris at all, you can just run the bandaw over the entire loop and center the areas you don't want a tight edge on. I'll try and post an example.

mabaza
08-25-2005, 09:01 AM
Surrealist:
I've tried subpatch weight, but haven't really had much like with this technique.

I have had some luck with breaking out the object into separate meshes, as you suggest. That way bandsaw only hardens up the specific piece I am working on. But sometimes, you really want your object to be one continuous mesh...

I definately suck at planning my models. I think this is something that improves with practice, but at this point I too often can't plan my model that far in advance. I think its a conceptual thing...I'm just not that good at thinking in 3D space. I'm much better now than I was, that's for sure. :king:


Telamon: I know many people swear by spinquad, but I have never been able to grasp how to integrate it into my workflow. I'm not sure totally understand what you are describing. Do you know of any tutes that have a real world example of this? That would be great!


Dodgy: Excellent idea. I've never thought of that. I'll give it a go when I get home tonight.

:lwicon: :thumbsup:

evenflcw
08-25-2005, 09:03 AM
Fastest way to limit what polygons bandsaw will slice through is to select the all the polys in the loop you want to slice, flip, then bandsaw, and flip back.

But seriously now, everyone, including NT, should DUMP Bandsaw, Bandsaw Pro and Quicksaw! There is one tool that does it all - Cut (the one under Modeler Tools; comes with 3 presets). NT should also rename this tool for OBVIOUS reasons while they're cleaning up all the redundant crap. Sorry for capitals, but I get frustrated thinking about how nonchalantly tools are slapped on.

Personally I use Add Edge with Stopper whenever I want to sharpen up an edge as there is no other alternative in LW that can offer the same kind of precision (absolute distances, yey!) aswell as preserve the orignal edge.

hrgiger
08-25-2005, 09:08 AM
Here is what I mean. The first pic shows a simple object that you want to tighten one of the edges on. The second pic shows the shape after running bandsaw. The areas in green you want a tight edge on, the areas in blue you don't. The third pic shows 4 points selected and centered on the existing polys so they don't create a sharp edge where you dont' want them. Some manual tweaking may be required to keep the proper curvature of the model.

Personally, I would rather just make a tri and a quad instead of bandsawing the entire loop. You would be surprised where you can get away with a triangle.

Dodgy
08-25-2005, 10:04 AM
I also tend to use cut more now. However, FI's Wrinkle tool is also good since you can put points either side of the ege you want to sharpen, and it gives you an even better edge. Get it here.

http://www2.ocn.ne.jp/~fis_junk/plug/win/FIsWrinkle-i-0_1_0.zip

Surrealist.
08-25-2005, 11:55 AM
Surrealist:
I've tried subpatch weight, but haven't really had much like with this technique.

I have had some luck with breaking out the object into separate meshes, as you suggest. That way bandsaw only hardens up the specific piece I am working on. But sometimes, you really want your object to be one continuous mesh...

I definately suck at planning my models. I think this is something that improves with practice, but at this point I too often can't plan my model that far in advance. I think its a conceptual thing...I'm just not that good at thinking in 3D space. I'm much better now than I was, that's for sure. :king:


Telamon: I know many people swear by spinquad, but I have never been able to grasp how to integrate it into my workflow. I'm not sure totally understand what you are describing. Do you know of any tutes that have a real world example of this? That would be great!


Dodgy: Excellent idea. I've never thought of that. I'll give it a go when I get home tonight.

:lwicon: :thumbsup:

Turning out to be a good thread. :)

I never use subpatch weight either for all of the reasons stated in this thread, though as I said on a case by case basis it could be an additional tool.

Hrgiger illustrated beautifully what I was talking about as far as separating the edges to control tightness. I think you got that though

Spinquad is a pesky little animal. I'll get to that in a minute.

Pardon me for quoting myself but I am going to despense some info I don't want to retype. Then I am going to give some illustrations. This is something I have been thinking about for a while so now, you asked, your it. :)

First of all here's an overview of some similar tools. (stick with me there is a point to all fo this)


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.

So what's the point in all of this?

The point I am comming to is it does not matter what tool you use to do so, your mesh to be currently subpatch "legal" really will only have a certain set number of configurations. OK this may be obvious, but when you think about it it helps you with planning and also understadning not only the mesh you are editing but using things such as spinquad.

Now Edge Bevel I would normaly put into the class of the above cut tools however there is no option to not have tris unlesss you bevel the whole loop but then it is more of an interactive bandsaw - nice tool as dodgy points out. I think it was kind of desinged really as a quick interactive way to add a beveled edge to a box but it has many uses also depending on if you are in poly or point selection.

Some people swear by well-placed tris, SlineGod for one, www.splinegod.com I am not going to argue with that. My preference is to do away with them. A little extra effort always finds a way to get rid of them. I just think it is a good practice for animation. When you start deforming with bones, endomorphs, dynamics and so on, I don't think you want to find a pesky tri that is causing smoothing errors. As I said just my preference.

So with that disclaimer, there are only two, that's right, two poly configurations you will ever need in subpatch.(currently as of v.8) It does not matter what tool you use, what method, how you come around to it, you will still come back to this place, so it is good to understand it and think with it while designing or editing your model.

These two configurations come out of two concepts in subpatch:

1) Cross hatch (grid) mesh
2) Polyflow (edge loops)

The two configurations are:

1) Four Poly point vertices
2) Five poly point vertices

Of course as you probably know 6 or more poly vertices should be avoided. So with these avoided and the quad only rule (my preferecnce) this leaves only two possible configurations.

A good clean model in my opinion comes from smooth integration of grid and polyflow.

So you could say that a mesh is just this: edgeloops inbedded in a grid.

This creates 5 poly points on the edges of the edgeloop as it connects to the grid.

Even if you use the step down method from higher to lower poly area you are really just creating the start of an edgeloop in a mesh when you analyze it (you will find the 5 poly point there) and this is why this method can give you trouble too. It can cause bumps in unwanted places and make the mesh hard to edit.

First pictures shows these two configurations. Basically an edgeloop in a grid. It is srurrounded by 5 poly points.

Second picture is the step down method in subpatch mode to illustrate the concept of the start of edge loops at the point where the mesh steps down.

By the way this is completley fine for low poly meshes and at times the only way to go. It's all in the planning as you can see with that head it works out not to be in a bad spot.

Last two are examples of polyflow, edge loops in grid on a high-poly head model.

The same can apply to a lower poly model.

So in the end all these tools get you to the same place. If you are having trouble controlling your mesh check if you have the correct polyflow or if you have inadvertantly started an edgeloop where you don't want it.

You can use this info also to control places where you want detail as you originaly asked.

As to spinquads, Larry Shults (splinegod) has some great examples on his site on video. I think the dead tutorial.

http://www.3dtrainingonline.com/support/

That would be my input. :)