Untitled Document

THE LEG
In this chapter you’re going to build a leg for Callisto and attach it to her torso. Since you’ll be building her boot using a different technique later on, you’re just going to concentrate on the waist down to the mid-calf area. You’re also going to uses a new building technique similar to a Boolean that’s more like a manual Boolean: you will shape an object to fit a specific region (in this case the posterior) and attach it to the target mesh (the torso). Of course there will be lots of edge manipulation and vertex tweaking as well as raw face creation. First, make the main leg shape.

I’ve hidden everything and zoomed in to the leg profile in the Right view. Like all appendages, the leg is essentially a cylinder that bends so it makes sense to start the shape with a Cylinder primitive. Switch to the Top viewport and go over to the Create panel. Hit the Cylinder button and make a cylinder anywhere close to Body Guide with a radius of 3, a height of 20, 5 height segments and 8 sides.

You need enough height segments in the cylinder to support matching it to the guide shape and 8 sides makes for a pretty detailed leg that can be optimized later on if necessary. Go to the Right viewport and move the cylinder over and up so it rests within the guidelines.

STEP 2:
SHAPE THE CYLINDER TO MATCH THE GUIDE
Now that the cylinder is roughly in place you need to tweak its vertices to match Body Guide. Apply an Edit Mesh modifier to the stack. Select the top row ofvertices andNU scale them 87% along the X-axis. Rotate them -15 degrees along the Z-axis and move them up a little along the Y-axis so they rest at the point where the curve of the buttock terminates.

FYI: COLLAPSING VS. STACKING
An alternative to adding an Edit Mesh modifier is to simply collapse the stack of the cylinder to an editable mesh. A good rule of thumb is if you don’t think you’ll be accessing the modifiers in the stack…collapse it. Many times, the decision to collapse or build a stack up is one of those personal preferences that can be argued both ways.

Next, grab the second row of vertices from the bottom, scale them 65% along the X-axis, rotate them 20 degrees along the Z-axis and move them down so that the far right vertex of the selection set is resting on the top of the curve of the back of the calf.

Select the bottom row of vertices, scale them by 80% along the X-axis and move them over so the far right vertex is resting on the top of the boot and about mid calf.

Go to the third row up from the bottom select them, scale by 80% along the X-axis and move them down to be at about the middle of the kneepad area.

Select the fourth row vertices up from the bottom, scale them by 65% along the X-axis, rotate them by -20 degrees along the Z-axis and move them down into place at the top of the kneepad.

Next, go to the second row down, select them, scale them by 85% in the X-axis, rotate them -10 degrees along the Z-axis and move them down along the Z-axis to about mid thigh.

Notice you didn’t try to add the folds of the back of the knee area or add enough geometry to match the guide precisely. This is because it would add too much geometry and definitely require optimizing later. Details such as small folds that don’t add hugely to the design are the first to get reduced if the polygon count goes over your 1500-triangle limit. Details like this are also easy enough to add if the face count is lower than the target.

Switch to the Front viewport and move the cylinder over so it rests approximately within the guidelines.

The shape still looks like a featureless cylinder in the Front view, but you know it looks correct in profile. Thus, when making tweaks in the Front view you need to restrict moving or scaling vertices to the X-axis (or side-to-side). You also need to keep in mind the impact rotating a group of vertices will have on the profile you’ve already established. Select the top row of vertices, scale them 85% along the X-axis and rotate them 15 degrees along the Z-axis.

Select the next row of vertices, scale them by 75% along the X-axis, rotate them 10 degrees along the Z-axis and move them over just a hair or two along the X-axis to line up with the guide.

Next, select the remaining vertices and scale them all along the X-axis by 50%. Move them over to line up on Body Guide.

Finally, select the bottom row and the third row of verts from the bottom and scale them back out by 120% along the X-axis to give the kneepad and the calf some thickness and shape.

Hit P to go to a Perspective viewport, zoom and pan until the leg is in view and hit Ctrl E to show the hidden edges of the mesh.

Notice how there is an extra vertex at the top and bottom caps of the cylinder. This is so additional cap segments can be added if necessary both at the time of creation and at the base parameters of the cylinder.

FYI: CYLINDER CAP SEGMENTS

I haven’t yet found the need to add cap segments to a cylinder, but that doesn’t mean it isn’t a useful feature! If you need them they’re easy enough to add. Just enter the number of segments you want in the Cap Segments box under Parameters.

Normally when it comes to cylinders, I collapse it to an editable mesh once I have the right number of segments and Target Weld or delete the center cap vertices. In this case however, you need those end vertices to extend the geometry and create better connecting points from the leg into the rest of the body.

Still in the Perspective viewport, select those two end cap vertices and scale them along the Z-axis by 125%.

STEP 3:
BOOLEAN THE LEG TO THE TORSO
Keep going with the mesh you have or load Callisto12.max from the CD. You’re going to attach the leg to the torso by using a Boolean/Union operation, but first, give yourself enough mesh overlap to get a proper Boolean. You need to extend the leg geometry up into Torso using face extrude.

With the leg still selected, go over to the Modify panel and make the Polygon sub-object active. Select the top faces of the leg, hit the Extrude button and Extrude-drag another set of faces up towards the torso by about 3 units. Notice the small extrude icon when you place your cursor over eligible faces.

After extruding them, move the conveniently selected faces slightly up and to the right so they correspond with the guide and fully penetrate the torso mesh. Do this for both the Front view and the Right profile view.

Now you need to prep the torso as well as the leg before performing the Boolean. Start by reducing the faces of the lower region of the torso to make a cleaner Boolean (too many faces make for just that much more cleanup after the Boolean).

Take the second line of vertices from the bottom of Torso and one by one, target welding each of them to the vertex on the row directly above it.

Next, go to a Perspective view and select these two sets of vertices at the bottom of the torso. Enter a value of 2 in the Weld Selected box...

...and hit the Selected button thus welding the vertices and reducing the faces even more.

Alternately weld the following two sets of vertices using a value of 10 in the Weld Selected box and hitting the Selected button.

Now the Torso is in better shape to be Booleaned. With it still selected, go to the Create panel, go to the Compound Objects menu and hit the Boolean button. Click the Pick Operand B button green and check Union under Operation. Rotate the view so you can see what you’re doing and click on the leg object.

STEP 4:
CLEAN THE VERTICES OF THE BOOLEAN SEAM
The leg is now attached, but you need to do some cleanup along the line where the two objects have been joined. First, get rid of half the torso so you can work on one side and later copy and mirror it to the other side.

Switch to the Front view, apply an Edit Mesh modifier to the mesh and select the [icon_verex2.tif] vertices mid to lower left of the torso mesh and delete them.

Starting with the front of the hip area, select this group of vertices, make sure your Weld Selected value is still 10…

Rotate your view to the right, select the next group to the left of the first and hit Selected.

Select the next bunch below where you just Weld Selected, turn on the Target Weld button and drag the vertices up to those vertices you just merged.

Rotate your view so you can see the next group near the groin area, select them and hit the Selected button again.

Continuing to rotate your view so you’re now looking at the inner thigh, Target Weld the next vertex to the one above it.

Rotate your view so you’re looking at the back of the character, select this ugly group of excess vertices and merge them into a single vertex using Weld Selected.

Keep rotating around to the next clump of vertices at the side of the hip and collapse them into one.

Now zoom in and select these two groups and Target Weld them to this vertex above them.

Rotate your view towards the front slightly and merge this mess of jumbled verts.

Finally, rotate back around to the rear, grab this vertex and Target Weld it to the vertex above it (leg34). It doesn’t do much in the way of suggesting a nice rear shape, but it cleans the geometry up, prepping it for later on when you build the butt.

The previous welds were designed to simply ‘clean’ the mesh up. The shape is important, but it’s always important to keep your work surface tidy. Booleans are convenient but will come back to haunt you if you don’t go over the seam and do the type of optimizing you just did. Merging clumps of unattractive vertices after a Boolean operation is par for course and expected but can be lessened by paying close attention to the points where the two objects meet. As in all aspects of modeling using your mind’s eye to visualize the outcome of a Boolean helps you prepare the two objects beforehand and save some time and effort.

STEP 5:
SHAPE THE HIP AREA
Now that you have the raw material to create the leg and hip area you need to tweak the shape so it looks right. Emphasizing once again the importance of knowing your anatomy, check out the following illustration created from a render of a high poly mesh that represents a typical female figure:

There are definite lines formed where the stomach ‘V’s down to the groin area made from the rectus abdominis muscles, but they are also formed by the protrusion of the iliac crest portion of the pelvic bone and the tensor fasciae latae muscle of the upper thigh. Even in low poly character creation this sort of anatomical knowledge is important. If these lines are apparent in your mesh, it can only increase the quality of it and reinforce the illusion that this piece of CG represents a humanoid character.

Load Callisto13.max from the CD. I’ve detached and hidden the arm so it’s easier to see the lower body profile.

FYI: MASS MODELING Hopefully you’ve come to realize my main modus operandi when it comes to modeling is to give myself enough mass to work with and then spend time refining it to meet the shape I’m after. Using this technique, it’s up to you and your deadline to decide just how much refining or tweaking you do to a mesh, but keep in mind the differences you see in other artist’s models are largely due to the time they spent or didn’t spend tweaking it. As you get more experienced, your speed will increase and you’ll make these sorts of changes intuitively and more quickly based on previous experiences.

You have the raw material for the front hip area; you just need to shape it up. Start with these five vertices and move them over to form the sweep of the tensor fasciae latae muscle.

If you compare the mesh before and after the moves, notice how in addition to better defining the hip area, the longitudinal lines of the mesh that run up the side of the hip and torso are now smoother.

FYI: MESH LINES Seeing your mesh in terms of lines is an important modeling concept. It allows your brain to look for influence lines and patterns in your mesh like evenly distributed faces. When those lines and patterns are ‘off’ you know it intuitively and make minor adjustments to get the mesh where you want it to be.

Before you go to the Front view and make more tweaks, zoom in and turn this edge:

That way it tucks back in along the abdomen and matches the guide even better. Go to the Front view and weld vertex 1 to vertex 2 (this keeps the number of lateral lines even and the faces evenly distributed) and move the other vertices over into the following position.

What you’ve done is basically match the lines of the mesh to the natural shape of the torso. Now, hide Body Guide, switch to a faceted Perspective view with Edged Faces turned on, and rotate your view around so you can see the mesh better.

Although it looked right from the side, the front of the mesh still needs work. The upper thigh muscle needs to go further towards the edge pf the hip and not the abdominal area. You need to adjust the thigh and add a vertex using Edge Divide to complete the sweep of the tensor fasciae latae muscle.

Next, turn these edges so when you move the vertices to create the leg shape at the top, all the edges are convex or ‘non-dented’.

FYI: WHY TURN AN EDGE…PART 2 I went into detail in an earlier FYI why I decide which edge to turn...

I concentrated on making all edges as short as they can be. Doing this keeps the faces evenly distributed and the overall detail of the mesh proportionate. Another reason just as important to turn an edge is to maintain its volume. By this I mean during the modeling process I find myself arc-rotating my view in a faceted view to find any divot or dent caught by the default lighting (or custom lights). As soon as I find an edge that is an unnatural crease or divot…I turn it. Turning concave edges like ensures a nice smooth surface on the mesh as well as giving the mesh optimal volume.

In render A notice how upper triangle of the edge indicated is slightly darker than the one below it. This indicates a concave edge. Turning it make the surface more even and adds to the illusion of volume to the mesh (render B). An uneven surface caused by edges in need of turning are one of the most frequent flaws I see when critiquing someone else’s model and detract from the quality.

Now move these vertices to smooth the curve of the lower abs and upper leg/hip.

Finally, do some minor tweaks in the abs area to create better lines. Turn these edges and move these vertices.

STEP 6:
SHAPE & POSITION THE REAR FOR ATTACHMENT
Now that the front of the torso looks cool, it’s time to work on the backside. Look at the following. It’s also from a render of a high rez mesh of a typical female figure:

I’ve identified the major muscles that define the buttock area. Of course there are many muscles that define the leg, but in Callisto’s case her boots obscure most of her calf and foot area so the focus is on her butt. In a female figure the shape of the bottom is rounder than a typical male’s due to more fat storage. Terms like ‘hour glass’ figure and ‘curvaceous’ when applied to the feminine form come from the fact that it has more curves than the more angular male form.

To create the rear of the character, first you’re going to build and shape a geosphere to approximate the gluteus maximus and gluteus medius muscles and then use Face/Create to attach it to the torso. This is similar to using a geosphere for the rounded surface and Boolean/Union to attach it, but this time you’ll avoid the messy results and subsequent cleanup of a Boolean operation by prepping and manually attaching the shape. Load Callisto14.max from the CD.