Maya | Poly Modeling II

Organic Modeling

Smooth, polish, and optimize your work.

Welcome back! In the last lecture, we covered how to manipulate objects to form whatever shapes we wanted. In this lecture, we will be discussing how to refine those shapes into smooth, polished models. Adding detail to our model, of course, increases the poly count so we will be focusing a bit on efficiency. Also important in working with more detail is the habit of creating clean even mesh geometry at all times.

By learning to only add the geometry we need where we need it, and by maintaining a good mesh topology we can make meshes that are quick to make, quick to animate with, and look good all without sacrificing the other.

The point is, regardless of what you are working on—a 500-poly game model or a million-poly movie character—you'll always want things to be optimally arranged to look as smooth and good as possible.

Before we begin, make sure that your menu set is set to Modeling in the upper-left corner of the interface.

Neat Clean Grids

In order to understand what makes good geometry, and what contributes to poly counts, we need to learn a bit more about how Maya treats each face, and how this correlates to actual polygon counts. Although Maya uses faces with any number of sides, there are two kinds of faces that we will focus on: quads (short for quadrilateral) and tris (short for triangular). As you might imagine, a quad has 4 edges, while a tri has 3. Generally speaking, you want your mesh to be as close to 100% quads as possible.

On the left a square made from one quad, on the right, divided into two tris.

When your graphics card attempts to render your mesh in real time, either in Maya viewports or in a game engine, all it really cares about is triangles. A quad becomes two triangles, like above, a 5 sided face might become 3 triangles. When we talk about poly count for models, really we are talking about how many triangles it takes to break down all the faces in the model and render them appropriately.

Although this gear has 580 faces, when triangulated, it becomes 3,760. The difference is high because the main face of the gear is so complicated.

You might wonder why we don't simply work in tris to keep tabs on our model's size. The fact is, it is advantageous to be able to work with non-triangular polygons. You can manipulate them more easily, some operations perform better on quads, certain functions only work on a lovely all quad mesh. To help keep track of my polycount and how it differs from my face count, I find it useful to bring up the poly count heads up display. To show this, go to Display > Heads Up Display > Poly Count.

Poly count

You can get at a lot of other nifty information in this menu as well. The poly count shows the counts for all objects that are visible (left), all objects selected (middle), and all components selected (right). You can see here that the object I have selected has only 12 faces, and the face I have selected is actually represented by three triangles. That face is clearly a candidate for converting into several quads.

Unfortunately, Maya doesn't always triangulate things quite the way you want it to. This is frequently fine, but when working with extremely low poly counts, it can be important, and is one of the reasons you might end up with some faces in your model that arent 4 sided. The reason is that there are many ways to divide faces. A quad can be divided across its diagonal to the left or to the right. On a flat quad, this rarely makes a difference. But say you had a non-planar quad like this:

Non-planar quad.

If this quad is triangulated across the bend, it forms a nice bent fold. But if it is triangulated against the bend, it forms a little valley. The two shapes are different, and in a low poly area, this may change the silhouette, or shading, of your model. You can change which way a quad is triangulated with Edit Mesh > Flip Triangle Edge.

The same quad, triangulated two ways, produces two separate shapes.

Since it's easier to work with quad grids, this sort of fine tuning is best saved until you are satisfied with your model, and just need to export it, tweak it, or reduce its poly count.

Multi-Cut Tool
The Swiss Army Knife of Polygon Tools

Now that we know a little bit about our goals for editing meshes with free form tools, we can talk about the tools themselves. Or really we can focus on this one tool: The Multi-Cut tool, found in the Modeling Toolkit window. As the name implies, Multi-Cut is actually a context sensitive tool that combines many older tools into one. Depending on the components we click on, or what modifier keys we press, Mult-Cut alone can help us radically transform our model.

Let's just jump into an example here. We will explore a few functions of the tool and focus on keeping good quad geometry as we work. In this example, I've arbitrarily chosen a nose, a difficult organic shape. To start, we will use a basic primitive, a pyramid.

The most basic nose possible.

I've deleted the back face of this pyramid, since this will be attached to a face at some point. This is about the lowest poly nose you can make: It has just three tris. But lets make it a little more detailed with Multi-Cut.

The first step is to save us some trouble as we work and turn on symmetry in the toolkit, in this case across the X axis. Next, with the model selected choose the Mulit-Cut tool. Taking care to click on the edges, I can click on the outside of the nose and then the inside edge. A line appears indicating the location of a new edge, and big fat vertices show up on the edges that are interesected. Clicking on these vertices lets you adjust the positions after the fact, or you can press Enter to complete the cut. The symmetry takes care of the far side. Once the geometry is cut, we can pull the new vertices out a bit to create a broader nose.

First cut to shape the bridge.

Now we are starting to get somewhere, but hold up! Notice the top of our nose and the bottom are both triangles, and we want quads everywhere. We can insert an edge going vertically on the side of the nose that will make both of these areas into quads and give us more detail to shape the tip of the nose.

With the nose selected, click Multi-Cut and start at the middle of the new edge we made. Holding down shift while working with this tool snaps the mouse to specified points along the edge, as a percentage of the whole edge. This makes precisely locating an edge across a series of faces easy. I used shift here to snap to the middle on both top and bottom, and pressed enter to complete the cut.

Second cut adds detail and fixes the top tri into a quad.

That fixes the top triangle, now that face has four sides like we wanted. The bottom face though has now gone from three sided to five sided since we cut both ends. Let's use our tool to add a slice down the middle. If you click-drag along an edge, the tool will stop when you encounter a vertex such as the one at the tip of our nose, which helps ensure that you are starting from an existing vertex and not making two very close together. On the inside edge we use snap to ensure the new vertex is precisely in the middle of our nose. You may have an easier time temporarily turning off symmetry for actions performed entirely in the center of your model.

Third cut fixes the bottom five edge face into two four sided ones.

This latest cut is actually dual purpose, it also gives us one solid line of edges down the middle of our model, which is a great idea when creating symmetrical objects.

Moving back up to the bridge of the nose, let's make this nose have a pronounced kink, to give it a distinctive profile. A kink requires at least two edges close together. Since we only have two or so edges to connect, we could click on them individually, but what if we wanted to insert two edges nearby and had a lot more geometry? We can use a new function of Multi-Cut to do this: Insert Edge loop. An edge loop is a series of edges that runs the length of your model. Having consistently spaced and contiguous edge loops is a great way to make sure your geometry looks good. Insert Edge Loop traces a path through your geometry and creates a new edge loop at even distances between the vertices. It's great for adding in detail along one axis, but it only traces a path through a quad mesh!

To use this function, hold down Ctrl with the Multi-Cut too selected and mouse over the mesh but don't click yet. You can see a preview of where the series of edges is going to be. Notice that now that we have made the top and bottom of the nose into quads, Mulit-Cut can find edge loops going vertically and around the nose. Find a path near the existing nose bridge and click to finalize the cut.

There is one last option for making a cut through your model with this tool, and that is the Slice function. Slice lets you draw a line over your model and will cut all faces it intersects at that line. This is great from removing sections of a model that arent wanted, or for making an edge loop thats not an even distance away from the rest. Lets slice our nose at an angle to get some more definition in the nostril area. If you are slicing across the axis of symmetry, this works best with symmetry off.

Slicing a model

Using these functions we can keep inserting loops and edges as we need them and growing the level of detail in our nose until we are satisfied with the shape or until we hit our target poly count for this model. Keep in mind that these tools can be combined with any of the tools from the previous lesson as well. Often you will cut a face so that you have an appropriately shaped area to extrude, or to place an edge where you want a bevel.

First extruded, then adjusted the edges a bit for the next extrude, then brought in the nostril with another extrude.

Making Polygons From Scratch

Are you the kind of person who needs absolute control? Does everything have to be just so? Is there a place for everything and everything in its place?

Well, the Create Polygon and Append to Polygon tools are for you. These tools let you place vertices by hand. This is good sometimes when you need to trace a complicated shape, or have a certain profile in mind to extrude. It's difficult to build stuff out of these tools entirely but they can be good starting points and/or situationally useful. Often these outlines have to be divided with Multi-Cut to maintain good geometry, but it can be faster to trace a tricky shape out with Create Polygon than to get there with extrusions.

Create Polygon is in the Mesh Tools menu, and to use it you just have to click where you want new vertices. As with many tools, you should beware of using it in perspective view, as vertex placement can be unexpected. If you press Ctrl and click inside the active polygon you are making, you start making a hole in your new polygon instead. I mostly use this for extrudes, or to make reference shapes to help me later.

Creating a freeform polygon is good for tracing an outline as a starting place. It can then be divided into proper quads with Multi-Cut (on the right.)

The Append to Polygon tool (Mesh Tools > Append to Polygon Tool) is a bit odd. Like its cousin Fill Hole, it looks for border edges. Border edges are edges that do not have a face connected to all sides, such as those that occur when you delete a face from an object. Append to Polygon lets you connect up as many of those border edges as you want, or if you are so inclined, start building a new polygon that's attached to one of the edges.

To create an object suitable for this task, create a primitive (a cylinder is shown below) and delete a face. This creates some border edges you can append to. Select your object, and choose Append to Polygon Tool. Now, if you click a border edge, little pink arrows will appear indicating valid locations to append to. The direction of the arrows matters, so click them in order, or confusing and icky twisty things will happen to your new polygon.

Append to Polygon

Smooth Operator
Removing the Rough Edges From Your Models

You'll notice most of the models you've worked on, and most of the examples in the lectures, have had a few things in common: sharp edges, faceted corners, and chunky curves. We fake curvature by making the triangles small enough that we can't see them. If a triangle is less than a pixel tall, there's no functional difference between it and a smooth surface.

The problem is, we don't generally want to work with objects that are so dense. Even if we wanted to deal with that hassle, we wouldn't be able to use them for real-time applications like games. So, we find a happy medium. Things don't need to be perfectly smooth. They just need to look smooth. This is the first of many "cheats" that occur in 3D work.

Normals

The first way to cheat is to pretend there are more faces than there really are. Take a surface with three faces on it. The one below was made by using Multi-Cut twice on a single quad, and the resulting shape was bent by dragging the vertices. It could also have been generated from a poly plane with three subdivisions, or by extruding edges from a rectangular quad. What'd I say earlier about skinning a cat? In any case, it has three faces, and therefore three angles to reflect light (and thus three values it is shaded). But if we average all three faces into a gradient, then we have an infinite number of ways it can reflect light, and we get a smooth gradient.

The only difference between these two objects is the way the normals are displayed.

In order to do this, Maya uses the "surface normal" of the face. The normal is the line perpendicular to the face. If the normals are "hard," the face is shaded all the same. If the normals are "soft," they average themselves with adjacent faces to determine what value of shading should occur. This makes objects seem much smoother. Notice, however, that the profiles of the two arcs are the same. The normal averaging trick is just a trick. It doesn't change the actual geometry, and edges will still look faceted if caught in silhouette. Also, if there are too few faces, or if the angles are too sharp, some bizarre-looking stuff can crop up.

To adjust the normals, go to Mesh Display > Soften Edge or Mesh Display > Harden Edge.

To have Maya automatically try to soften any edge that's close to flat while preserving sharp corners on harder angles, use Mesh Display > Soften/Harden Edge and choose an angle in degrees. Any face that has an angle of incidence with its neighbor greater than the value set will soften. This helps prevent some of those funny artifacts that come from softening angles around 90 degrees. Set to Face, also in the Normals area of the Mesh Display menu, will stick all the normals back to their original, perpendicular positions.

Subdivisions
Making Your Model Look Better With the Click of a Button

One very common way to model high-res models with polygons now is to work with a lower resolution version of your model, and then let the computer use an algorithm to subdivide it and display it high as if it were a higher resolution mesh. This method is the one I use 90 percent of the time. It balances the total freedom and control of poly modeling that comes with a manageable number of faces, and the need for a high-resolution smooth appearing model that stands up under close ups.

Because this method is so common, Maya has built a mode into the viewport that will automatically display your mesh while under the effects of this subdivision algorthim. To see your mesh as it would appear with smoothing applied, select a mesh and press the "3" key.

On the left is the actual poly model while on the right is the smooth displayed version. Click to enlarge.

You can work with your model when it is displayed in the smooth preview mode, but you may notice that while hovering over edges and vertices will properly select them, the actual pivot of your manipulator is way over where the original mesh was located. That's because the actual manipulable vertices are still the ones on your non-smoothed version, you are just looking at them differently. You can see an overlay of your original wireframe by pressing "2", or return to normal view by pressing "1". Since flipping back and forth between view modes is so quick, I often just use 1 and 3 when shaping a model, and only use 2 when I am getting a confusing selection.

Highlighted vertices are actually the exact same vertex, thats why the manipulator shows up

So what is going on here under the hood? Poly smoothing works by taking each face, subdividing it a number of times (4, 16, 64, and so on) and then averaging the position of those new faces according to each adjacent face. To see this, make a poly cube, and perform a Mesh > Smooth action on it. You can see it becomes spheroid. This is because the "influence" of each face is strongest near the center of the face and progressively weaker near the edges. Since a cube is even, it creates an averaged version: the sphere. By increasing the number of Divisions in the Channel Box, you can make things smoother and smoother. Usually one or two is sufficient. Stay away from anything higher than 3, as it usually just adds more density than is worthwhile.

Smoothed cubes are hardly cubic anymore.

Notice that the object loses volume the smoother it gets. This means that whatever shape your low-res mesh may be, it will become smaller when you smooth it. Also, take a look at the geometry of the cube on the right: its a super even quad grid. Compared to a sphere primitive, this is often a much better place to start modeling a round object, as the mesh is full quads, even size, and good edge flow. Applying a smooth node to your model when its a very roughed out shape is a good way to get quad based geometry to work with going forward.

Smooth previews, or smooth nodes both end up with a bit of a conundrum though. Part of the model is wonderfully smooth and contiguous appearing, but what about those areas we wanted sharp? Since smoothing of the mesh is essentially a complicated average of the geometry, we can control it by weighting the average with more geometry where we want it. The closer together the edges are, and the more of them, the sharper the corners will be.

Adding in extra geometry with Multi-Cut edge loops turns the sphere from above into a cylinder.

When you are making a higher poly model versus a low-poly model, you might know in advance that you will be using some sort of subdivision on the final geometry. You can plan ahead in your modeling and double up on sharp corners, or use Bevel to create geometry where you want sharp edges. Another option is the Mesh Tools > Offset Edge Loop function, which works much like Insert Edge Loop but places two edges on either side of the selected edge loop. You can always flip back and forth as needed to see the effects of your new geometry, until your character has both the smooth areas and the detail you need.

Here a little figure was made for smoothing. It started off as a rectangle, and was molded into this general shape. You can see the head is square, but smoothes into a round shape. To ensure a squarer body, detail was beveled into the corners. Then, to add detail to the "chest" of the character, Insert Edge Loop added a few more cross sections to get a defined curve.

When you know your model's final destination is not going to be staying in Maya (Or exporting as a point cache), you can use a feature of Maya subdivision algorithms that let you sharpen corners without adding extra geometry, called Creasing. Creasing is a way of weighting edges in that averaging algorthim, so that you don't need to mess with a bunch of bevels or edge loops in the corners.

Using Mesh Tools > Crease, select and edge and MMB Drag to increase or decrease the level of weight an edge or vertex has. Creases are denoted by heavily shaded edges, and you will find that how an edge or vertex affects the mesh is also related to how the components connecting to it are weighted.

The same basic sphere from before, but creased. This cylinder looks very similar to the version with extra geometry.

Characters: Building Your Evil Twin

Before we get started on characters, let me make a small disclaimer: There are hundreds, if not thousands of ways to model. I will go so far as to say that there is one way to model for every modeler. I'm going to show you how I like to build humanoid characters, and this process is similar to how I was taught. I think it's a good starting point because you will learn to adjust your technique as you progress, just like I did. New technologies will be developed and from that new challenges will broaden the way you need to think about these things. There is no one right way, though there are certainly plenty of wrong ways (insert ominous thunder). For now, let’s just shoot for good results.

This funny little guy was modeled with polygons and smoothed, using only tools discussed in this lecture. (He was then textured using tools we'll explore in Lecture Four. Ignore the man behind the curtain.)

One thing to keep in mind in all modeling: If no one ever sees it, and nothing ever touches it, don't model it. This means you don't need to model the engines of most cars, the insides of most clocks, and frequently, the entire bodies of clothed characters. A good deal of work can be avoided by not spending your time doing unnecessary tasks. If a character is wearing a jacket, you don't need to worry about his upper arms. If a character has a big metal piece of armor over his shoulder, you may not need to attach the shoulder smoothly. Long skirts save the work in connecting legs to hips—the list can go on.

The simple segmented design of this robot was chosen to save poly count at the joints and ease deformation.

Characters are usually everyone's favorite thing to model. We are going to go quickly over the process of putting together a humanoid model. This will be your exercise for this lecture as well, so you may wish to read that first, and keep it in mind or follow along as you go.

To start, you need to know what you are working on. Humanoids are complicated, and they are tricky. We expect to see certain things. Small adjustments can make a person seem alien and creepy or make them have character and warmth. People spend so much time looking at people that they are really very good at detecting things that are unusual. This means anything that remotely looks like a person requires a higher degree of precision and attention to be successful.

In order to ensure your proportions and details get put together right, it helps to have a reference image right there with you in Maya. First, you need to put together a few sketches of your character from different angles. Front and side at the minimum. Back, top, and three-quarters helps too. Character sheets with these views are freely available on the web, as well as generic humanoid forms:

This is the character sheet I was given to model the character you've seen so far. Click to enlarge.

To bring your images into Maya, go to your front view. From the View menu (at the top of the front view window), choose Image Plane > Import Image. An image object will appear in your scene. If you open up the attribute editor (View > Image Plane > Image Plane Attributes), you can adjust its size, visibility from other cameras, transparency (called Alpha Gain), and so forth. If you de-select it by accident, the only way to re-select it easily is by going back into the View menu of the view you placed it in, and choosing Image Plane > Image Plane Attributes again.

Image planes are great references to have, because you can line up your geometry and outlines precisely against them, taking some of the guesswork out of tricky models. The act of using an image plane as a reference is referred to as rotoscoping because it is similar to the traditional animation technique of the same name. Rotoscoping traditionally means drawing over a frame of film to produce your image (such as the music video for A-ha, Take on Me, Google it).

This shows the model laid over the reference. This helps ensure accuracy in the drawing. You can see a few small deviations made after the model was finished (longer arms, for instance). Click to enlarge.

The Chicken or the Egg? Creation Order

With a model like a humanoid, it's not always clear where to start, and what order to do things in. I like starting with the torso, because it is the center of the model. As with most objects, I start with a primitive of suitable shape: usually a cylinder with 8-12 cross-sections (depending on how detailed I think the character is going to be). I scale, and then tweak the cylinder into place at the torso. It helps to turn symmetry in the Modeling Tookit while working on a character, this way you don't have to alter both sides of your model.

Front, side, rear of the rough torso. Notice that the general curves of the edges match the body, even before they are refined or attached to anything.

Don't worry too much about the areas near the shoulders and neck. They will sort themselves out when we have those parts.

I usually build the arms separately, then attach them. I do this because I find it's easier to not worry about the joint, and instead focus on the arm. Then, once I have the arm the way I want, I can bring it over and figure out how to attach things without mangling my hard work.

I usually construct my arms starting with hexagonal or octagonal cylinders. Remember, in either low poly modeling or modeling for smoothing, start with less and add in. In constructing your arms, take care to insert some cross sections with Multi-Cut near the elbow and wrists to ensure proper bending later. Although we will not be rigging these characters for animation in this course, it never hurts to start good habits early.

Arms with flipper hands. Note the cross sections deformation (distortion of the model when it is animated) much later.

Now that we have the arms, I put them in place on either side of the torso, and need to join them. There are a few ways to do this. The first step is to perform the Mesh > Combine function on the two pieces. This makes them one poly object. Then pull vertices in the arm and torso to sort of line up with each other as best you can.

If both objects have solid caps with the same number of faces (unlikely unless you've planned it that way) you can use the Bridge function by selecting the relevant faces and clicking Bridge in the Toolkit.

The second and most reliable way is to create a hole in the torso by deleting any faces the arm will cover up. You can then can use Append to Polygon to bridge the gap. If you don't want to add in an extra ring of geometry, you can use Target Weld in the toolkit. This tool works by click-dragging one edge or vertex to another where the two will be joined up. Both edges must be border edges for this to produce good geometry.

This is an elaborate process. First, the pieces are joined. Then they are adjusted to fit each other better and internal faces are deleted. Next Append to Poly, Merge, or Target Weld are used to close the gap. Click to enlarge.

Once the areas are combined, I use Multi-Cut and re-tool the area to look nicer. You'll want to make sure that you've made a good set of quad geometry in the connections. Getting your edges to look sensible is not only aesthetically pleasing, it helps later if the character has to move. Try to put some concentric circles around the neck, and running over the shoulder. Contiguous edges are your friend.

A tool that really helps with adjusting organic models is Soft Selection. You may have seen the tab in the Modeling Tookit already. Soft select means that whatever transformations you apply to a component are applied 100% to that component, but also to everything in a radius, falling away to zero. You can adjust the size of the radius (and the profile) in the toolkit, or by holding "B" and MMBdragging back and forth to increase or decrease radius. There is a visual display of how strongly an area is affected by shading the components with a heat map, which makes it easy to see when your radius is affecting the area you need.

After a bit of point pulling, Multi-Cut, and Soft Select the shoulder looks much better. Click to enlarge.

You may have noticed that Merging up your geometry has ruined the symmetry of your model. This is easily fixed before moving on with a quick Mesh > Mirror. Be sure to have the midline of your model at zero on the X axis, select Cut and Combine With Original as options, and mirror away. Now your symmetry is restored!

To attach the legs, I usually form an angle at the hips first. This is easily done by rotating the top crosssection appropriately, then adjusting the one below that a little less, and so forth down the leg. Once the leg is properly shaped, it can then be joined to the torso. This ensures the direction of my edges are optimal ahead of time. The groin is tricky since you have two cylinders coming into one area, and in some cases you will be best suited connecting the inside edges of the legs to each other instead of the torso. It's best to attach both legs before worrying about the best edge flow and eliminating odd shaped polygons.

If your character is low poly, try not to model things like toes, even if they will be visible. Sock feet can be embellished with textures or adjustments, and people tend to concentrate on face and hands more, so detail is better spent there. Once your leg is constructed, attach it to the hips (if appropriate) and move on to the head!

Just like the arm, position the leg, join the vertices, and then polish it up. You may need to mirror your model before everything is done to help get the groin right. Click to enlarge.

Every head is different, which makes it difficult to say how to model one. For a low poly head, I usually start with subidivided cube, and roughly shape it before extruding ears and noses out, and perhaps a mouth in. Then I add any important details with Multi-Cut, getting my edges aligned correctly. A higher poly face is the subject of a whole lesson or more, as it involves a significant amount of re-arranging edges for good animation. Just for reference, below is a face of a character who's poly budget was 10,000 polygons. Notice the loops around the eyes and mouth, instead of a simple grid. You won't need to do anything this detailed for the exercise, but keep this in mind if you start to add in some facial detail.

Facial modeling is a complex topic into itself, so try to keep the heads of your first few characters simple.

Once the parts are all attached, I check my poly count and add details. Adjusting proportions (don't forget Soft Select!) should be done at this phase. Once more, I go over the model and check to make sure I don't have any 3 or 5 edge faces that I don't need. If there are any accessories or extras, like pouches, hats, weapons, badges, and so forth, I build them separately at the end.

Final Character. I decided the torso was too skinny at the end, and so I fattened him up a bit. I also tacked on a very rudimentary face, mostly to include the giant nose made earlier.

Reducing Poly Counts
Nothing But the Best Geometry For You  

The time will come for all of you: Your model is finished, it's beautiful—flawless in every way. Every vertex exquisitely crafted and placed with both artistic verve and mathematical precision. And then the memo comes in: "Looks great, but it's a bit heavy, can you reduce the poly count by say... 40 percent?" Tears will flow.

So, what to do? Sometimes, things just don't work as dense as we made them. I've made pieces of geometry that looked pretty low poly, and I thought I was pretty clever. But then when it was duplicated a few hundred times in a scene, things got sluggish. So you take it under the knife.

Reducing poly count is a tricky business, and involves a combination of elimination, merging, and unfortunately, remaking. Let's start with the worst case: remaking.

Sometimes an object has a simple shape, but just too much density. Maybe its a box that was beveled way too aggressively, or a sphere that just had its cross sections set way too high. Rather than selecting and deleting every other section from the sphere, its often faster just to leave the existing object there as a template, make a new lower poly to overlap, and the delete the original. You can even use Snap tools to ensure your corners and so for are in exactly the same places.

Simple shapes are generally best remade. This handle is reduced from 2000 polygons to only 200.

Eliminating unnecessary components is the next step. Of course, its easy to feel that all our components are necessary, but some are just more necessary than others. Components that define silhouettes are much more important than components that simply make a subtle curve or bit of shading clearer. Going over your model and removing unnecessary edge loops is the fastest way to significantly drop the poly count. Double-click on an edge to automatically select an edge loop, and be sure to use "Delete Edge" so that you don't orphan any vertices, otherwise your poly count won't drop at all!

On the left the original waitress's legs, on the right edge loops that dont change the curvature much have been selected and deleted to reduce the poly count.

Sometimes an edge loop is very important on one side of the model, but not on the other side. This is frequently the case with the knee, for instance. Other times you might have a larger number of edge loops coming into a smaller number, like where the arm joins the shoulder. In these cases you need to do a little more than just delete edges, since you'll end up with a partial loop that terminates into a 5 or 3 sided face. Sometimes that's OK, particularly if you are staying in Maya and/or its in a hard to see spot, but other times you'll need to fix it with quads.

Take the simplified example below. I need to remove an edge from one half of the plane, so I select those edges and delete them. You'll notice that I get one five-sided face and two four sided. The solution is to merge down the vertices (Edit Mesh > Merge to Center) on top and bottom of my new five-sided face, all the way down the row where our edge was. Then adjust the placement of the remaining vertices to soften out the transition. You can also use Target Weld on edges or vertices to eliminate extra faces if you find it simpler.

Eliminating only part of an edge loop takes some care to preserve good geometry habits.

Discussion Share your thoughts and opinions with other students at the Discussions Board. Exercise Create a detailed character model with a prop, staying within poly count guidelines.