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View Full Version : my female is giving me problems, her polygons arent working right



somnambulance
05-02-2005, 03:18 PM
This is my first human model I dug up and decided to finish. For some reason it is acting up though. I can't figure out why the polygons are doing what they are doing. I have tried deleting them and re-making them. I have tried flipping them, but they are facing the right way. They all have 4 points, no more and there are no doubled up polys. I reset the weight map to 0. She is getting funny creases across her forehead, and nose between her eyes. The geometry is also messed up only on sub-d to the left of her eye, and is okay with radiosity on (?, wack).

If anyone can help I would really appricate it.

bobakabob
05-02-2005, 03:40 PM
A high maintenance female Lightwave object? Looks like you have a mix of single and double sided polys with different surface names. Select the entire model, go to Surfaces and assign the whole model a single surface. Call it "Skin 2" or whatever. That should do the trick.

Bob

somnambulance
05-02-2005, 04:24 PM
They were all labled "skin". I made a skin 2 anyway and loaded some LW presets in, here is the results. It looks like it has to do with the incidence angle. So I have no idea how to fix it.

Something else is weird about it, if I delete two adjacent polys, one that is doing this and one that is not, and go clockwise with my point selection, one will have to be flipped and the other will not. Any ideas?

Dodgy
05-02-2005, 07:22 PM
Definitely try giving the whole section the same surface and then merging and Unifying them, it does look like doubled polys... You'll have to make sure they use the same surface if you want them to unify...

somnambulance
05-02-2005, 08:16 PM
Yeah, I am getting totally frustrated with it because its something I have never seen before. I probably could have started the head over and been done in the time I have spent trying to figure it out. I did this model back in LW7 and the polys werent very clean to start with... I think I just might half *** finish it and start a new one later with clean geometry. This one could be a toon shaded character maybe. If anyone feels like taking a look, I attached the model's and scene.

Surrealist.
05-03-2005, 03:56 AM
Hi, downloaded your model.

Took a quick tour but the first thing I did was unify polys and it eliminated 4

These pictures show the main problem you are having with her and I'd have to say that the diagnosis is in and it's as nasty case of triangles.

Check out the images below and see just a few areas I found.

Then after that it's pollyflow. There are some problems, tight spots that are pulling her around the bridge of the nose - as an example.

I have a couple of links for you to check out:

http://www.puffandlarkin.com/lightwave/tutorials/character_modelling/

This one has a link to this:

http://www.suture.net/tutorials/modeling/index.php

I know you said this is one of your early models and I am sure you are beyond it now but a good brush up every now and then on the basics is good. You will definately find all of the info you need there to fix her up.

somnambulance
05-03-2005, 07:55 AM
Thanks for checking it out. I figured the points with more than 4 polys were giving me problems. I moved a bunch of them to where they will be hidden, which is why there are now 4 times as many rows of polys going up her forehead. This is teaching me that cleaning up models is harder than just doing it right in the first place. I bumped the sub-d's up to 12 and it fixed it, 9 wasn't enough... I still dont really understand why the sub d polys are breaking up on the shadow lines, I guess because they are adjacent to a 3 sided poly?

somnambulance
05-03-2005, 07:59 AM
oh, I am folowing the book "3-D Human Modeling and Animation", I probably wasnt reading the whole thing or skipped something when I started the model way back.

Surrealist.
05-03-2005, 01:41 PM
Thanks for checking it out. I figured the points with more than 4 polys were giving me problems. I moved a bunch of them to where they will be hidden, which is why there are now 4 times as many rows of polys going up her forehead. This is teaching me that cleaning up models is harder than just doing it right in the first place. I bumped the sub-d's up to 12 and it fixed it, 9 wasn't enough... I still dont really understand why the sub d polys are breaking up on the shadow lines, I guess because they are adjacent to a 3 sided poly?

Yea, those nasty 5 and 6 polly points. And yes angain to those that are next to the threes sided polys. 3 point polys should be avoided completely for sub D.

I am starting to look at it this way, a general rule of thumb:

THE CLOSER A VERTEX GETS TO CREATING A TRIANGLE-LIKE SHAPE (ANGLES) THE MORE IT IS LIKELY TO PRODUCE SMOOTHING ERRORS IN SUB D REGARDLESS OF HOW MANY POINTS THE INDIVIDUAL POLYGONS HAVE (3 OR 4).

So it goes without saying that triangles are out since there is no way for them NOT to have such angles in thier shape.

When you look at a 5 or 6 polly vertex it is looking like a set of triangles even though the individual pollygons are quads. This is due to the angles created from that common vertex.

If you stretch out the points of the pollys on even a 4 polly vertex you can get a similar problem depending on the situation and of course we are talking about creating uneven, bumped, abrubpty raised or curved geometry -as in an organic shape like a head.

This is on no way a "technical fact" based on some kind of isight as to the interworkings of the code, just a practical observation and thus good working rule of thumb.