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Nurbs Tutorial by Travis Stringer


Before you try to make a head with nurbs it is important to know a few things. First off, expect to spend days working on it. It will take a while so don't expect to do it in a few hours. Second, Nurbs editing can get real slow. Especially if you are editing a full head. The more points you have the slower it gets. So add rows and columns of points sparingly. Also max nurbs is not fully developed. So you may experience some annoying problems. Although nothing that a little time can't fix, it is still something you should be aware of.

Nurbs has a few advantages over polygons. One of them (the most obvious) is that you will be working with curves. Everytime you edit a point the surface will react in a curved nature (unlike polygons). Another advantage is that once you have a nurbs head it is easy to make another head from that one. Simply by editing a female nurbs head you can create a male head, old man head, child head ect. I suppose you can do this with surface tools as well but nurbs is easier and faster to edit. You can see your character in real-time unlike surface tools.

Front and back spline

The method I used is one I learned from Jeremy Birn (www.3drender.com) and involves starting with a profile spline. I begin by creating a point spline. Cv splines are awkward to use and you can always convert a point spline later. You set the axis of the spline at the top of the head. Then you clone the profile spline and rotate it. With the new spline rotated about 5 degrees you have to edit it. Bring the points in around the eyes and make the lips smaller. This is hard and takes some time. Then clone the spline rotate it and edit it again. You continue to do this until you get to the ear. Then you start with the back spline and do the same thing until you get to the ear. One thing to note is that all the splines DON'T have to have the same number of points. Around the cheaks I erased alot of points because it didn't need alot of detail. This process is VERY important so take your time. The more work you do here the more time it will save you later.
After the splines are created, attach them all. Then collapse them to a point surface. It is imortant to collapse to a point surface because right now we don't want to deal with a bunch of cv points. Now click on ULOFT in the surface creation panel. Starting with the profile spline create a u-loft surface between the splines. You will end up with a very ugly looking head. Start by editing and erasing points you don't need. Make the surface as smooth and good as you can. You will not be able to really start editing until we make it into a cv surface. But again editing now will save time later.

Now for the real editing. Under sub-object/surface, click on MAKE INDEPENT. It will convert your head to a cv-surface. Now go under sub-object/cv surface and you will see all the cv points. You will need to edit these points to finish the head. Before you get overwhelmed there are a few tools that help you out. One is Affect Region. Affect region allows you to move a region of points by just moving a single point(I use this alot). You will need to edit the affect region curve. Another one is weight. By increasing a points weight you can give a model more detail and a sharper look (corners of the mouth). Where you have a bunch of points that all come together you can use FUSE. Fuse will make them all come to a single point.

The highlighted point is a point I deleted to get rid of the that wrinkle.

   
I begin by editing the nose. You may need to add a column or row of points for the nostril of the nose. Under sub-object/surface/refine add a column or row running thru where the nostril will be. Now select a point in the middle of the nostrill and bring it up in the z direction. Now increase it's weight. It will pull the nostril up more. Edit the points on the outside of the nose and increase there weight as well.
The eyes are tricky and take some time. One thing that helped me was to look at the lattice and the direction of it. Alot of times when editing you need to look at the points and the lattice and NOT the surface. Then you can see what might be wrong. You will need to add rows and or columns to get more detail in the eye. Study the shape eye by looking at a picture will editing. There is no real secret so just do it.
The mouth is fairly easy. You will probably need to add some points/ columns for the mouth. Increase the weight in the middle of the mouth and corners. Depending on the type of character you will need add middle rows to make the lips look more full.

This is a pic of the lips after I joined the sides

   
After half of the head is done don't get too excited. I thought that it would be a simple process of just cloning the head, mirroring it, and then joining it to the other side. It seemed that no matter what I did the head always got a little tweaked after I joined the 2 halves. It was not to easy joining the halves so here are a few things that you might want to try. First attach the 2 halves (sometimes it flips the normals of one side when you do this). Then click on sub-object /surface/join and join the 2 surfaces. Depending on your settings and how far apart the halves were, the head will get tweaked differently. After they are joined select the whole center row of points it added and delete it.

If this did not work you may want to first create a blend between the 2 halves. Then make the blend independent. Then join all 3 surfaces together. The bad thing about this is that you cannot erase the center column of points.

No matter which method I tried the head always got a little tweaked. So you are going to have to go back and reedit. This is a real pain because now editing will be extremely slow. Since now the head has twice as much points. So go back to the joining part and do the best you can there. Then edit.

Once you have edited most of the head I go to the top of the head and fuse the points. Fusing the points will make all the points one single point and smooth out the whole top of the head and forehead. To fuse points you select click fuse, then select a far point and bring it to a center point. Make sure that you bring all the points to the center point and not vice-versa.
The great thing about nurbs is that once you have a head you can easily make another. The wizard was made from the female head in about 2 hours. Most of that was waiting for the computer (PII 300). If you have a dual 300 it should speed things up. I created the wizard head by pulling cv points. Creating bags under the eyes and looser skin around the cheaks. Also making the lips thinner , head and jaw longer and stronger. I made the eyes thinner and made one wider and bigger (magic eye). Most of the detail was created using bump maps. The textures were from a old man picture.

Since max nurbs is new and there is very little info on them, there may be easier steps that I may have missed. If you have any tips or something to add please email me at Travis@Dreamsoft.com and I will post it on my site.

Travis Stringer

www.dreamsoft.com/travis

   


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