Poly Head Modeling

Ok. I've put this off for a long time, so I've finally decided to sit down and write a tutorial on modeling. After going through tutorial after tutorial on modeling in poly's/sub-d's, I've come up with a workflow that works very well for me and hopefully you too. My co-workers jokingly call it "the Dave Way".

First off you should have a side and front view of the object (sometimes top too, but I don't need one in this case because most of my detail can be defined in the front and side). When creating these pictures it's a good idea to use graphpaper so that you can make sure your detail is lined up horizontally.

Once your pictures are drawn, scan them in and save them as jpegs (it's a good Idea to make them no larger than 400 pixels wide. The larger your images are, the more memory they will take up and it will slow your progress). Then create a project directory in maya and save your images in your source images folder.

The next thing you're going to want to do is create 2 planes. One facing the front view and one facing the side view. Create a material for each of your drawings and assign them to the appropriate plane. Turn the transparency of the materials down to about .5, then assign the 2 planes to a layer. Assigning them to a layer will allow you to do 2 things...

1.) it will allow you to reference the planes so that you don't accidentally select them while you are modeling
2.) it will allow you to make them visible and invisible at the click of a button.

Once you have all that out of the way, you are ready to start modeling.

Using your create polygon tool (located under polygons>create polygon tool), draw a silhouette outline of your picture in the side view. If you misplace a point while placing them down you can always hit the backspace key to undo the point or press the insert key to edit its placement.

After you've created your polygon silhouette, the next thing you're going to want to do is subdivide it using your split polygon tool (located under edit polygons>split polygon tool). The trick to keep in mind here is to follow the contours of your drawing while keeping the amount of subdivisions down to a minimum. The more subdivisions you put in on this step, the more points you will have to move in the future. Keeping your subdivisions low while placing them in points of detail will make your modeling go much smoother.



1.) Start out by creating the contour that defines your eye and cheek bone. You should end it off at the bottom of the chin.
2.) Then create a split in the opposite direction that begins on the ridge of the nose, goes through the center of the eye, and ends in the back of the head.

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3.) Now is probably a good time to define the jaw line. Take this split up through the top of the head. When placing your splits, try and stay half-way between the two outer edges (this will create a cleaner mesh in the end).
4.) Next, define the line where the mouth will be. Then bring it to the back of the head (notice how I'm placing my edges half-way between the outer edges).

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5.) Then split up the top of the head a little by drawing an edge from front to back.
6.) Define the lower edge of the brow by running an edge from front to back.

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7.) Next define the snout by running an edge from the nose to the bottom of the jaw.
8.) Break up the neck a little by running an edge half-way between your two outer edges.

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9.) Next, define the outer radial of your mouth by creating an edge that meets with the corner of the mouth.
10.) Finally... split up your mesh a little more so that you have even spacing between your edges..

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Once you have subdivided your mesh you will need to clean it up a little. You might have created more points than necessary and we want to keep our points to a minimum so that it will be easier to edit further up the road.

To do this you must first select all the verticies within your silhouette. Leave the border edges alone for now they are still needed to define the shape of your object. Also slelect the inside verts of the neck border leaving the outer 2 alone.

Then press the delete key on your keyboard. This will clean up any hanging verts leaving only the ones that exist at intersections.

Once your mesh has been cleaned up, again select all the inside verts (including the ones on the inside of the neck)

Next thing we want to do is bring this model into the third dimension. We do this by simply going to the front viewport and pulling the selected points toward the the outer edge of your drawing.

To give you more of a sense of form while modeling, it is a good idea to create an instance of your object. An instance is an object that shares the same shape node but has a different transform node. Making it an exact duplicate of your original geometry just at a different point in space. Therefore, any changes you make on one side will take place on the other instantaniously.

To create your instance, go to edit>duplicate and open your options dialog box. Check -1 on the scale X direction, then under geometry type check instance.

Now you have the beginnings of your head... not much to look at now but it soon will be.

When modeling, I find it easier to see my wireframe while I'm working. To view your wireframe in your viewport go to shading>shade options>wireframe on shaded.

To start shaping your object, start grabbing verts and begin moving them only in the X direction. Use your front view as a guide. For example...go to your side viewport and grab the point that defines the corner of your mouth and then move it in the X direction to where the corner of the mouth is in the front viewport. Don't worry if your mesh looks really rough at this stage, that's the way it's supposed to be, we're just roughing out the form of the head at this point. Think of this process as if you were carving from stone. First you start out really rough to get the form of your object, then you go in and define the forms a little better... and then (but no sooner) you go in and create details.

Next look at the point where your eye is in your side viewport, make sure that it is directly in the center of your eye in the front viewport. Then create a diamond shape with your split polygon tool. This will begin the radial of your eye socket.

Then subdivide the diamond one step further so that you may better define the socket of the eye. As you split your edged try and split as close to the center as possible.

To visualize the eye better, create a nurbs sphere and place it in world space according to your front and side viewports. This doesn't have to be your final eye... just a place holder so that we can form the eyelids around it correctly.

In your front viewport move the points of the eye radial so that they fit to your drawing. Then in your shaded perspective view pull those points one at a time in the Z direction until they ride the surface of the nurbs sphere.

These points will define the eye lids of your head. The next thing your going to want to do is create another radial around the lid to help define that shape a little more.

Grab the verts of this radial and push and pull them in space until you get a good looking eyelid.

Our guy is still a little rough but he's shaping up quickly. It's good to work as light as possible to define your shapes quickly. Don't go overboard trying to add in detail... that will come later. Right now just concentrate on creating the form of the head.

Next thing we will work on is the nose. To start out, draw an edge starting at the upper lip going straight up passing through where the center of the nostril will be and continuing up into the forehead.



As you add in new edges, you should push and pull the points to define your shape better and make it rounder.

Next, we will have to create an intersecting edge to create a point that will define the center of the nostril. Start the edge at the beginning of the upper lip and carry it through to the bottom of the nose. When you run an edge to define a point of detail, always try and run it so that it conforms to the natural flow of the face. Think of the way the muscles and folds of skin flow and try to run the edges that way, this will help you define your edge loops. Notice how I run mine so it follows the natural curve of the face.

Also keep in mind that when you draw these edges you are trying to stay directly between your two outer edges.

The next step is to start to draw in the radial of the nostril. Draw a diamond around the nostril center.

Sub-divide the nostril just as you did with the eye so that you can make it rounder and give more detail to that area.

Then push and pull these points to define the nostril a little better. Notice I'm not adding too much detail to these areas before I move on to the next area.I'm just defining the shape a little, then moving to the next area that needs a little more definition. The reason for this is that if I need to rearrange the direction in which my edges go later... it will be much easier to do with less detail.

Next, we'll go in and define the shape of the lips a little better by adding another radial inside the existing one. This will give us the information needed to define the roundness of the lips.

Next, add some information to the lower lip, going in the opposite direction, all the while splitting the edges evenly.

Push and pull the points you just created to give more roundness to the lip. Our guy is really starting to shape up. With very little effort we've begun to define the shape of his head quite nicely. The main thing to keep in mind (and I can't stress it enough) is to work rough and loose. Try not to get caught up in adding too much detail... that will come in time. It makes it a lot easier to define your shapes when you only have to move a few points as opposed to moving a bunch of them.

In the next few steps we will clean up our mesh by making our edgeloops a little more defined and add detail where we
need it.

First off, I'd like to talk about edgeloops and what makes a good clean mesh. Our ultimate goal is to make a single mesh that consists mainly of quads (4 sided polys) that flow with the natural curvature of the face. Ideally, you should be able to pick any face on your mesh and follow it around a path that conforms to the flow of the face. This is called an edge loop. If you follow your path and it suddenly stops due to either a three or five sided poly, you're loop has been broken and you should clean that area up. Here is a picture indicating the loops of the head I'm modeling. The radials are in red and the opposite direction in blue.

If you create your edgeloops correctly, adding detail and deforming your mesh for facial poses will be a breeze. Try and remove any three or five sided polys as you work. It's better to get rid of them at this stage then to wait too long and try and get rid of them when you have a lot of detail.

Next, I'm going to start adding in some more detail and clean up my mesh along the way. I'll add in a ring around the eye to help define the eye socket and cheekbone, then I'll add an edge from the center of the eye to the tip of the nose. This will help define both the tearduct and the roundness of the nose. And finally I add in an edge to break up a five sided poly near the mouth and clean up my mesh a little.

Next, I'll add in another loop to the eye to define the crease where the eye meets the brow. Then I'll throw in a couple loops to help define the roundness of the upperlip and the shape of the chin. As I add these loops, I might need to get rid of existing edges to create a continous loop with no three or five sided polys. Use the delete edge tool (go to edit polygons>delete edge) to remove unwanted edges, then redraw your edges in the corect manner using the split polygon tool.

Then I'll split up the eye a little to better define the roundness of the lid, plus I can use the rest of the edge to help define the brow and cheekbone.

Next, I will throw in a few more edges around the corner of the eye to create the tearduct. These edges will also help define the wrinkles on the ridge of the nose. I'll also throw in another edge around the bottom of the brow to help make it more distinct. Then, I split up the faces under the nose to create more information for the upper lip and cheek bone.

Now that we have the shape of the eyelid pretty well defined, we can go ahead and create the eyesocket for this guy. Start off by creating a loop just inside the eyelid loop. This will define the thickness of the eyelid.

Next, create two more loops, an inner ring and an outer ring. These will be used to create the depth of the eye socket.

Grab all the points of the inner ring and push them back in the Z direction (into the head) then take all the points of the outer ring and scale them informally to create the underside of the eyelid. If some of these points penetrate the outer surface, just simply move the points back in space. Now you should have a fairly descent looking eye socket.

Next I'll split the eyes, brow, cheek and mouth to further the detail. While I do this, I'm getting rid of any triangles and five sided polys that I come across by running them into the newly formed edge. This also strengthens my edgeloop.

Notice the difference between these 2 steps. Notice how the loop now fits nicely around the brow, eye and cheek whereas before it didn't.

Now that I've got the loop around the eye cleaned up, it's time to go in and fix the loop around the nose. Notice how I have a lot of triangles and the edges aren't exactly flowing with the curve of the laugh line. I'll fix this by running some new edges in the right direction and deleting out the old ones.
Notice how the laugh line is now clearly defined.

Next, finish off the loops at the top of the head. Bring the edges down through the back of the neck to give that area more definition. You can also add on some of the edges that define the muscles of the brow. Then, split up the lower lip a little so that we can begin working on the inside of the mouth.

To begin creating the inside of the mouth, first draw a radial loop just outside the edge that defines the center of the mouth. Make sure you split the edges at the corner of the mouth instead of taking the edge to a single central point. If you split the edges you will be left with quads and this is what we want.

Next, select all of the inside faces you just created.

Then, press the delete key on your keyboard to remove them. This will create an opening in the mouth if you have split the corner correctly, you will have nothing but quads left over. If you have done it wrong, you will have triangles at the corner. If you do... fix them up by drawing in new edges so all you have is quads before proceeding to the next step

Next, go to your side viewport and view your model in wireframe. This will allow us to see where we are going to place the inside of the mouth.

Using your ep curve tool (go to create>ep curve tool) trace out 3 curves that define the inside of your mouth. One from the upper lip back to the throat, another from the lower lip back to the throat and a third beginning at the corner of the mouth, going half-way through the other two curves, all the way back to the throat.

Next, go into your perspective viewport and move the center curve in the X direction to the corner of the mouth.

Now that we have our curves in place, we need to create a surface out of them. I could simply loft them but this would
give me unpredictable results and put isoparms wherever Maya feels like. I want to have more control and be able to direct the iso's where I want them to go. So next we are going to force the Iso's to go the way we want them to.

The next illustration shows the direction I want the Iso's to go.

So... with that direction in mind... I right click over my curves and select curve point from the marking menu. I select the points where the red lines in the above illustration intersect the curves. This will leave a little yellow dot that indicates where we are going to cut our curve later. If you hold down shift while selecting the other curves you can perform this action on multiple curves at once.

Notice how the yellow dots line up directly with the red lines in the above illustration.

Once you have selected all your curve points, you should cut your curves. You can do this by simply going to edit curves>detach curves. Now wherever you had a yellow dot, the curve should be cut, leaving you with a bunch of little curves.

These curves are still not ready to loft yet. We must do one more thing first... rebuild our curves so that we have an even amount of isoparms on each surface when we loft them.

To do this... select all your curves and go to edit curve>rebuild curve and open your options dialog box. Set the number of spans to 3 and hit the "rebuild" button in the lower left of the box to apply.

Now we are ready to loft our surfaces. You might want to go to your viewport settings and turn off your polygon display to
make this step easier (show>polygons).

Start by selecting the top curve in front (upper lip), then holding down shift, select the next curve in the middle, then last but not least, select the bottom curve (lower lip). Then to loft them, go to surfaces>loft. Repeat this pocess for the rest of the curves.

Once you have created all of your lofts you should attach each surface together. First, select the the first surface, then (holding down shift) select the second surface. Then, using the attach surfaces command (go to edit nurbs> attach surface) attach them together. Repeat this step until you have a single solid nurbs surface.

Now all we have left to do is match the nurbs surface to the inside of the mouth. In order to do this we will need to match the information up. Ignoring the center edge and the mouth corner edge... count the number of edges that make up your upper lip. In this case we have edges.

In order to match up the edges with the inside of the mouth, you must insert 8 isoparms from the center edge to the mouth corner edge. In order to do this, right click over the nurbs surface and select "Isoparm" from the marking menu.
Select an edge and drag. You will see a yellow line appear, this is not actually an isoparm... it's just a marker indicating where you want to put an isoparm. Holding down the shift button you can insert as many yellow lines as you need.

After you have created 8 evenly spaced yellow lines, you need to create isoparms out of them. To do this, simply go to edit nurbs>insert isoparms and the information will be added for you.

When you are done repeat this step for the lower lip as well.

Finally we have a surface for the inside of the mouth. The next thing we need to do is convert it to polygons so that we can attach it to the rest of the head. To do this select your nurbs surface, then go to modify>convert>nurbs to polygons and open the options dialog box.

Under "Type" select quads

Under "Tesselation Method" select general

In the Initial Tesselation Controls section...

for "U Type" select "Per Span # of Iso Params"

for "Number U" select "1"

for "V Type" select "Per Span # of Iso Params"

for "Number V" select "1"

Then press the tesselate button in the lower right to convert it to polys.

Now that you have a polygon version of your mouth you can delete the other nurbs components used to make this surface.

Before you can connect the two shapes into a single mesh you should snap the verticies of the inner mouth shape to those of the mouth on the head. Go into component mode and select one of the verts of the inner mouth edge. Holding down V for vertex snap move it to the corresponding vert on the head shape. Repeat this step untill both edges are perfectly lined up.

Now that you have both edges lined, up the first step is to combine your geometry. Select both pieces then go to polygon>combine to join them. This will make Maya treat your 2 pieces of geomety as one piece. However, there still is a border edge seperating the 2 pieces. This will be evident when you go to smooth your mesh. If there is a border edge a huge seam will appear.

To view your border edge, go to display>custom polygon display and open the options dialog box. In the "Highlight" section, check border edges and in the "Border Width" section, put the slider to 5. Click apply and close. This will draw your border edge a little thicker than the other edges to help you see what your doing when you start to merge edges.

The next thing you're going to want to do is merge your border edges together. To do this, select your mesh and go to edit polygons>merge multiple edges and open the options dialog box.. Set your threshold to .01. This is important because if you set this number too high, it can merge your mouth shut. Press apply to merge edges. If there are some edges that didn't merge try setting it to .02 and go up from there until all your mouth edges are merged.

If your mouth didn't merge at all... you might have your normals flipped. If this is the case, go into component mode and select one face from either the head or the inside of the mouth, then go to edit polygons>normals>reverse and open the options dialog box. Set the mode to "reverse and propogate", then hit apply. This will flip the normals on the offending section, then you should be able to merge your seams.

When you are done you should have a single piece of geometry with no seam.

Once you've attached the mouth to your head, go ahead and finish off your loops. Finish off the back of the head and neck. Now is the time to add in any little details that you want. When you are finished with the one half of your model, simply duplicate it, combine it and merge the border edges the same way you merged the mouth to the head. Try smoothing it when you are done to see how it looks. Go to polygons>smooth.

Looks like this guy only needs one more thing to be complete... Wrinkles. Right now he looks a little smooth.

To create wrinkles while maintaining perfect "quadness" is a cool little trick.

Find the edge at which you wish to create a wrinkle.

Along that edge draw another edge just a little offset to it and connect at the corners.

Next divide the faces in the center, leaving the triangles at the ends alone. This will make quads out of everything.

Then pull the center edge inward to create your wrinkle.
Try smoothing your object to see the result.

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Here is the version where I added in some wrinkles.

And here is the final version after all the detail has been added.

Happy Modeling :)

Dave K.

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