# Theoretical SUB-D

#641

PiledotNet:
The edge loop stopped because u had a pole over there
wich means 5 edges coming out from 1 vertex.
u need to have 4 edges coming out from each vertex in the edge loop if u want it to be continues.

but i don’t think u will have too much problems with deformation in this pole over there (correct me if i’m wrong please)

Tal

#642

Hi Snot and tnks for this quick reply.

Reading the dicussion in this threat about poles, I tought too this was the problem but, i’ve made some tests. See the pictures below please.

Ok, here in this first picture I have an simple object with a simple complete loop:
http://www.redpixel.hpg.com.br/edgeloop06.jpg

Than, I split an edge to make a pole. Selecting an edge and hiting Edge Loop, I got the same Edge loop. :shrug:
http://www.redpixel.hpg.com.br/edgeloop07.jpg

After, I’ve created a polygon, to see whats going to happen with the loop, and again, the same edge loop.
http://www.redpixel.hpg.com.br/edgeloop08.jpg

I dont understand, some times, edge loop dont care about Poles, and some times yes. What I’m missing?

#643

PiledotNET:

Your example is a special case, and it really is more about how you look at it. When you select an edge, then hit the “loop” command, the edgeloop works itself around the object until it hits the pole. The problem with this example, is that the pole is right at the end and the beginning of the loop. It’s an illusion. It is terminating at the pole, but because it started there, it will find the entire loop. I’m finding it difficult to explain, so please forgive the vagarities.

Try making another pole at the other end of that edge, and you will see that the loop won’t make it all the way around, as it will encounter a pole before it terminates at it’s origin. With this example, the loop does not begin and end at a pole.

Hope some of that made sense.

And for the record, a pole is a vertex with 3, or 5 or more edges. A vertex with 2 edges is an orphan. There is also one acception to the “pole stops edgeloop selection” rule. If the pole or poles exist along an open area, ie, around a hole, poles can sometimes be selected. Peter(Urgaffel) can fill you in more on that one.

-3DZ

#644

Ok, Ive read every page in this thread and some more than once.
Because I have to work to eat I havent had much time to devote to my latest project. However, I have one problem that is recurring and I cant seem to solve to my satisfaction. How to repeatedly create notches or insets into 3D volumes via SubD / MeshSmooth techniques.

Currently my project is an Aircraft and I cant seem to cut out the ailerons and tab surfaces, for future animation purposes, to my satisfaction. No matter what technique I use I always seem to have an area on the surfaces that is not clean.

Enclosed are a couple of images of what I’m trying to do and also a MAX 5.1 file so you can play with the actual part involved. Every time I get the corners nice a crisp the slope of the wing/aileron area shows a crease or raised line and the inside corners of the Tab cutout, under magnification show a problem that may or may not show up when applying materials.

http://webpages.charter.net/dzignguy/images/aileron_00007.jpg

This is the MAX 5 file for revue

I really have learned tons from this thread and hope I can finally get this thechnique right.

Thanks, John

#645

I perfectly understood 3dzealot!

So, down here is a picture with 2 poles “breaking” the edge loop.

Tnks 3Dzealot and tnks again Snot!

Count on me to help you guys if some question comes up in this thread and count on me too if some tutorial comes out from this thread.

#646

3dzealot:
How do u know what is the begining of the loop and what is the end??
I mean it’s a circle. circles don’t have begining nor end.

and does a pole that appear in the begining or end have a different affect then a pole that appears in the middle when animating?

Tal

#647

Snot:

I know where the begining and end of the loop are because the exist at the same point.

As for how a circle has no beginning and no end, that’s true in it’s most fundamental geometric form, but this ain’t geometry class. That “loop” is not a circle. It’s a contigious set of edges bound by common verts. A “loop” does not have to be a real loop. It’s just a term for the structure of edges, and how they relate to each other. That’s why a “loop” can terminate anywhere. Poles are really important, else we might as well be using nurbs. It’s all about locate refinement, and if there is no way to break the loop, the darn thing will stretch across your entire model.

BTW, when YOU draw a circle, it has a beginning and an end. When the function goes out to find the loop, it has to start and end somewhere as that’s what the rules for finding a loop dictate. Because in his example, the pole is at the extent of the loop selection, it appears to select THROUGH the pole, but in actuallity, is is selecting TO the pole.

A pole is a pole. It will always cause some stange effects when rendered and when smoothed.

PiledotNET:

Glad that made sense. Out of all the stuff asked so far, that one was the hardest to explain.

-3DZ

#648

Hi again. Backing some pages, I’ve noticed some peoples are using scripts to Chamfer edges living the original edge. I’d like to share how to do this in 3ds max 5 without any scripts… See the result below and a little tutorial.

“Chamfered” Edge living the original Edge:

Create a Box for this experiment:
http://www.redpixel.hpg.com.br/extrude01.jpg

Enter in the Sub-object EDGE and select an edge or a group of edges:
http://www.redpixel.hpg.com.br/extrude02.jpg

With the tool Chamfer, the Edge will be chamfered but it will not leave the original edge of the original structure. That isn’t what we want:
http://www.redpixel.hpg.com.br/extrude03.jpg

So, to automate this, lets use the EXTRUDE. With the single or group edges selected, hit the extrude button:
http://www.redpixel.hpg.com.br/extrude04.jpg

Set zero to the Height of this extrusion:
http://www.redpixel.hpg.com.br/extrude05.jpg

And with the ‘Extrusion Base Width’ parameters, you can set the distance between the new edges from the original.
http://www.redpixel.hpg.com.br/extrude06.jpg

Whit a little cut, we can make it all quad, if you want…
http://www.redpixel.hpg.com.br/extrude07.jpg

#649

PiledotNET:

Yet another nice variation of chamfer! Ive learned soooo much from this thread! MeshTools also has a chamfer command that leaves the original edge. Quite Nice but very quirky as far as undo is concerned.

#650

Dzignguy: Just found your post on the previous page…we must have posted at the same time.

To get rid of that hard transition, turn on your constrain to edge function(if you are usnig R5), and move the edges down and away from the edge that makes up the primary corner.

-------------------------------------------- <----- Slide this edge
-------------------------------------------- <----- leave him alone
-------------------------------------------- <----- Slide this edge

See, the idea is that the closer edges are to one another, the more tension they create when smoothed. So if you just slide the surrounding edges away a bit, it will soften the transition.

-3DZ

#651

3DZealot:
Ok, got that!!! Now, how do I get that corner relatively square? Ive tried and tried everything I can think but still no joy!..This ole guy is sure missing something…

Heres the Change:

The Change rendered and smoothed:

However, still another and seperate problem arises.The corner is rounded too much.

I really appreciate your help, I dont know how you get around as much as you do. I see your moniker everywhere. In any case a big thanks!!!

John

#652

Hey, John, you’re almost there. You just need 2 more edge loops to weight that corner.

I posted a small .gif animation back on page 40 that should give you some ideas. I’m away from photoshop right now, else I’d draw them on your posted pic(might get a chance to do that later).

For now, have a look at the .gif animation here:

Be back soon…

-3DZ

#653

I’ve always found that the inside of corners like what your showing are the hardest part of modeling, it is the only thing i ever stumble on when trying to make a good looking model

I never really use the technique 3dzealot uses for inside corners cause on rounded objects it always adds creases to unwanted areas, so i spend most of my time seeing what i can do to make corners look good without uses that technique

i looked at your model and tryed somewhat copying it and seeing if i could work out the corners…this pic below is the best I could do to make it looks smooth and keep the inside corners

I also have the .3ds file if you want to look at it in max

#654

holosynthetic:

Thanks for the reply. It looks very good without materials or shaders so I will give that a try. I’m not sure but I think that leaving isolated “orphaned” vertices can lead to problems later and in shading. Thats not my experience just what Ive read… I love the ease of this …whats the scoop on this 3dZ?

3DZealot:
Have your gif file broken into single frames so I can look and look and look… : -) I think I understand what you are saying but my brain is fried so when you have a little time and can get to Photoshop I’d appreciate an addition to my screen dump to show me what edge loops need to be added.

Thanks again people, I really appreciate this help. Once I get this one down I will be a long ways to getting My connie ready for showing…

John

#655

Ok,
Ive done some more experimenting and there seems to be something different in the way the mesh smooth works with your cube with a square hole that has a floor in it and one without a floor. I removed the floor and deformation of the surface quads directly adjacent to the corner start to tear and the crease starts to show in the render… Am I seeing this wrong?

No floor in hole:

Floor in hole:

Am I doing something wrong here? This shight deformation carries out all along the horizontal line enough to show a crease in the rendered image…

My aileron experiment with the same edge loops as the Square hole in a cube: Obviously I’m missing something

#656

Add two more edges and you’re done (see attachment).

Also read through the basics once more, once it ‘clicks’ it’s real easy.

#657

Marcel:
Respectfully, You obviously know your stuff, I visited your page, the work there is great!!! I can only hope to get that good!

However, I guess you didnt look at the file I had on the previous page. Ive, done that and been there. For some reason, it doesnt work on this problem…at least the way I have it configured. When you add those two edge loops an obvious crease shows up all along the horizontal edge loop. I admit this is probably caused by the way Im building this shape but untill I understand where its wrong I’m stuck… I could easily model this thing as one shape, wing, aileron, and tab, and add material and bump map to show the aileron and tab but I want to animate the surfaces so I have to model the seperate parts and this “notch” seems to be my achiles heel…I’m also building the wing flaps that retract from under the wing and the same problem works ok because there is a “roof/floor” in the flap compartment of the wing. As you can see I’m really confused…

John

#658

-3DZ

#659

this kind of looks like one or two verts arent welded?
it looks odd to me

#660

3DZealot,
Thanks again for having the patience to keep me on the right track! I still get a slight crease with that configuration. I attribute that to the fact that the aileron surface is curved both in the verticle and horizontal directions. I must have had a badly constructed file the first time as that weird corner thing is gone now in the newly constructed volume. The crease goes away on a flat surface like the one you display in your last post. Interestingly the more curve I put in the verticle direction, perpendicular to the straight, horizontal edge loop, I get proportionately increased creasing. Oh well at least now youve shown me how to keep it to a minimum… Thanks again and on the the next challange…

Reeves1984: You could be right, but I didnt find one. I think that particular render was missing several edge loops…

John