Essential LightWave 3D- P8 pptx

Each of the points of the original poly exerts influence over how the subdivision surfacing algorithm creates the smooth surface of the sub-patch.. Sub-patch surface models can have thei

By default, LightWave viewports show a

sub-patch’s:

• Cage — The “ghosted” representation

of the poly that is defining the sub-patch.

• Surface — What will actually be

ren-dered in Layout

• Guide — A ghosted line drawn from

the surface to the point on the original poly

that “controls” (influences) it

Not quite sure what all the fuss is about?

Each of the points of the original poly

exerts influence over how the subdivision

surfacing algorithm creates the smooth

surface of the sub-patch The sub-patchsurface behaves a lot like stretchy, digitalclay

Even so, you still may be inclined tothink, “It’s a neat gimmick, but what can itreally do for me?” The upshot of this real-

time application of Multiply | Subdivide |

More | Metaform Plus is that you can

model extremely dense meshes using a

very light polygon “cage,” and you can do it with the tools with which you’re already

familiar!

Sub-patch surface models can have theirresolution dialed up or dialed down, not justwhile you’re modeling but while you’re

C h a p t e r 7 · · · ·

Figure 7-3

Figure 7-2

animating as well! Under Layout’s Object

Properties window, you set the resolution

at which your sub-patch model will be

dis-played and the resolution at which it will be

rendered (In Figure 7-3, that’s a difference

of 24,064 polygons!) You can animate with a

very speedy, low-poly mesh and render with

the ultra-polished 27,072 poly mesh

with-out having to change a single setting when

it’s time to render!

Now that I’ve got your attention, how do

you turn that sub-patch “blob” in Figure 7-2

into the character in Figure 7-3? You use

the Smooth Shift, Bevel, Drag, Move, and

Rotate tools

That’s it? Yep That’s basically it There

are a couple of other tools I use to make

things a little easier or to fix things when

my work shows me I’m lacking in the sight department, but for the vast majority

fore-of my character modeling, those five tools(always with a healthy helping of the Sym-metry mode) are the main tools I use when

modeling organic models.

Smooth Shift

Smooth Shift works with sub-patches just

the same as it does with polys (In truth,

you’re better off thinking of your sub-patch

not as some arcane, spline-based

“mysti-cism” but as polys that just happen to be

nice, soft, and “roundy” and are never

con-sidered “non-planar,” no matter how you

push their points.)

However, as nice as the real-time

work-ings of Smooth Shift are with planar,

polygonal faces, it often “splits” the mesh

apart at its points with sub-patches (similar

to what happened with the window ings when we rail beveled them in the lastchapter) There is a quick and easy fix tothis, though: Let Smooth Shift handle mak-

mold-ing the new geometry, and you handle

shaping and sizing it

Smooth Shift with an Offset of 0 and aMax Smoothing Angle of 0º is the best way

to work with sub-patches A simple way to

do this is to activate the Smooth Shift tool

(<F>) and then click without moving your

mouse (You can also achieve the same

· · · · M o d e l i n g 3 : S u b - Pa t c h O r g a n i c M o d e l i n g

Figure 7-4

effect by using the Super Shift tool

men-tioned in Chapter 3.) After smooth shifting,

position and shape the new geometry by

hand (It’s good to get in the habit of

smooth shifting your sub-patches with

these settings The tiny bit of extra time it

takes more than makes up for the headache

of finding a half-buried, “dismembered” set

of points much later on in your work, theresults of an erroneous Smooth Shift opera-tion you didn’t catch.)

BandSaw

The best characters are made up of loops

(or bands) of four-point polygons The

BandSaw tool can be used to subdivide

these loops into smaller bands You can

think of it as knifing along the path created

by the band of the polygons

When you have Enable Divide active inthe BandSaw window, the tool not only

selects the band of polys (along the U or V),

it also creates more segments in that selected band with respect to the band markers You create and position these

C h a p t e r 7 · · · ·

Figure 7-5

Figure 7-6

markers in the white area of the interface,

which represents the top and bottom of the

band of polys that will be selected/cut

Note

A good way to determine the path that

BandSaw will take as it cuts through your

polys is to use the Select Loop tool

(dis-cussed in Chapter 3) first.

• Add puts more of these band markers

wherever you click your mouse in the

• Value lets you enter a specific position

(0 to 1) along the white area for the

selected band marker

• Uniform repositions the band markers

you have, spreading them all out evenly

• Mirror creates a new band marker that

mirrors your currently selected one

• Reverse flip-flops the band markers.

• Clear removes all but one of the band

markers, placed exactly in the center

Multiply | Subdivide | More |

Band-Saw Pro does the same thing as BandBand-Saw

but with a real-time Numeric window

inter-face that lets you

still interact with

your viewports

while open The

cool upshot of this,

other than being

able to orbit your

model to see if the

segmenting is

working as you’d

like, is that it

doesn’t require you

to use its interface window It “remembers”the last settings you used with it andapplies them immediately when activatingthe tool (I’ve mapped this tool to a hot keyand assigned it to my Quick-Tools menutab, so when I want to select a band of mymesh, I just tap its hot key and keep right

· · · · M o d e l i n g 3 : S u b - Pa t c h O r g a n i c M o d e l i n g

Figure 7-7

Figure 7-8

What if you want to remove segments

from your mesh? LightWave has Construct

| Reduce | More | BandGlue, which

“stitches” bands of polys together in much

the same way BandSaw cuts them apart

The tool has no interface (just click its

button, and away it goes) The one big ference between it and its counterparts isthe direction in which you select the polys

dif-to be glued Just remember that you’re

selecting the polys that will become one band around your model.

Note

“Elegance” in Modeling

Something that takes most folks a while to pick

up on is an overriding concept of elegance in

whatever it is you’re doing in 3D This applies

to modeling, animating, texturing, lighting —

all aspects of working in 3D.

Your best work will come from using the

absolute minimum number of “whatsits”

needed to hold your “schiznit” in place — no

more and no less.

Tools like BandSaw can let you really load

up your mesh with lots and lots of segments,

and it’s very tempting to do so But the best

modelers build their meshes with the barest

minimum number of these isoparms necessary

to keep the exact shape they’re going for.

Sometimes a good modeler will spend half the

time it took to create the mesh just going

through it again and again, looking for places

he can optimize it and removing anything that

isn’t absolutely necessary to hold its shape.

This optimization not only makes for a

model that’s quicker to refresh when working

in both Modeler and Layout, but when working

with characters, it means that it is a lot easier

to rig (set up for character animation) It also

means that the bones that drive its

deforma-tion will create shapes that look a whole lot

better than on a mesh that has a lot of

seg-ments (See LightWave 3D 8 Character

Animation for complete information on

charac-ter rigging.)

To help us use as few segments as possible

in making our mesh do what we need it to, we

can adjust the weight by which the sub-patch

is controlled by its cage This information is

stored on each individual vertex as the

Sub-Patch Weight Positive values increase the pull

of the control vertex on the sub-patch surface, where 100% makes it touch its control vertex.

Negative values relax the sub-patch’s pull

toward its control vertex Map | General | brush is a tool that lets you modify the values

Air-of your currently selected weight map in real time.

It’s important to note that the vertices in your object are not inherently assigned to any given weight map, including SubPatch Weight While Weight Shade will show your vertices as having a value of zero, until you actually assign a map value to them, they have no value whatsoever You can directly enter values for selected points under the Information win- dow for your selected points, or you can use Map | General | Set Map Value While this information may not be of immediate use as you’re learning the software, higher-end functions such as Dynamics do utilize vertex map assignments, so keep this bit of informa- tion in the back of your head.

C h a p t e r 7 · · · ·

Figure 7-9

Modify | Translate | Magnet is a great

tool for working with your sub-patch

sur-face model as if it were a lump of digital

clay It’s a tool I use extensively to rough in

my basic forms when sculpting anything

organic (characters, heads, artifacts,

whatever)

With the Magnet tool active, you

right-click and drag in a viewport to set its

“sphere of influence” and then left-click and

drag to move your mesh around Points

closer to the center of the sphere of ence will be affected more than those at itsouter edge in accordance with the falloff.This is very similar to what we’ve seenalready with the Bend, Taper, and Twisttools

influ-If you establish (and continue to late) the Magnet tool’s sphere of influence

manipu-in a smanipu-ingle viewport, the sphere will be

more like a cylinder, extending infinitelythrough space

· · · · M o d e l i n g 3 : S u b - Pa t c h O r g a n i c M o d e l i n g

Figure 7-10

Figure 7-11

When you manipulate the Magnet tool’s

sphere of influence in multiple viewports, it

becomes a true ovoid that can be used like

a traditional sculptor’s tool, pressing and

pulling at a mass of Super Sculpey (The

Perspective viewport in Figure 7-11 showshow I usually like to work with my sub-patch models, with Independent Visibility

active and choosing not to show cages,

guides, or the grid.)

Pole

Modify | Transform | More | Pole takes

Size (Pole Evenly tool) and Stretch (Pole

tool), and blends them with the sphere of

influence of the Magnet tool This is an

underrated tool that is very helpful fororganic modeling — especially “futuristic”design

Vortex

Modify | Rotate | More | Vortex Tool

takes the Rotate tool and blends it with the

sphere of influence of the Magnet tool This

also is an underrated tool that is very

help-ful for quickly creating gracehelp-ful, fluid

curves

C h a p t e r 7 · · · ·

Figure 7-12

Figure 7-13

Subdivision Order

Does the order in which your sub-patch

surface model is diced up into its tinier

pieces matter? It matters a whole lot — and

one of the best ways to show this is by

using a variant on the old “single-poly

mountain” trick

1 Start with a 5x5 sub-patch grid

2 Bring the 5x5 sub-patch into Layout,

and set its Display SubPatch Level to

42 Then under its Deform tab, click on

the T button next to Displacement Map

to enter the Texture Editor, and set upthe dented texture shown in Figure7-16 We get a very cool “insta-moun-tain,” strongly reminiscent of theartwork of Roger Dean, the artist forthe Yes album covers

(Do you want to see something neat?

Activate World Coordinates for your

dis-placement map, remove your falloff values,

and then move your object about You’ll see

your object flow through the texture! It’s a

neat way to understand more about the

workings of textures in general Be sure to

try this in all three axes.)

The two inactive textures in Figure 7-16

are other examples of different kinds of

terrain

Mac-Specific Info

Because of the current weirdness with

the Mac version of Dented, Mac users

will have to use a Texture Value of 20.2,

instead of the 4.2 shown in Figure 7-16,

and play with the texture’s position in

order to get decent mountains (But it’s

worth it — no other procedural does

mountains like Dented.)

(Special thanks to Robin Wood!)

Load Scenes\Chapter_07\Subdiv_

Order.lws, activating each layer in turn, so

only one is active at a time, to see othernifty settings

Subdivision Order tells LightWave when

to apply its subdivision surfacing algorithm

to the polygonal cage If you tell it to apply

its smoothing last, the displacement map is

only displacing the 36 points of our 5x5

cage If the smoothing is applied before the

displacement map, the displacement maphas all 44,557 points to push about

Subdivision Order can really come intoplay when you’re working with animating acharacter The quickest, most reliable ani-mation comes from subdividing yourcharacter using the After Motion or Lastoptions This way, the bones are only hav-ing to calculate their influence on, say, 7,000points instead of the sometimes astronomi-cally high number of points in even aDisplay SubPatch Level setting (“animationresolution”) character’s mesh

C h a p t e r 7 · · · ·

Figure 7-17: Modifying the Subdivision Order setting.

If you want to freeze your mountain’s

defor-mations in place for use as a prefab object,

File | Save | Save Trans Object will save your

object as it exists on its current frame of LW’s

world-space — transformations,

displace-ments, bone movedisplace-ments, and all (Be sure to

choose a name different from your original

object; otherwise, you’ll replace the original

with the object as you’re seeing it right now in

Layout’s viewports!)

Save Transformed Object also respects the Display SubPatch Level setting “Exporting” our mountain as it exists in Figure 7-15 will give us

a mesh with 88,200 polys! If you want to save your transformed object as an object you can still use as a sub-patch model, set Display SubPatch Level to 0 before using Save Trans- formed Object.

.

Sub-patches open up a whole new level for

both modeling and animating Modeling

complex meshes can now be done in a

frac-tion of the time it would take to noodle all

those minute polys Animating with a cast

of sub-patch characters means once we

choose our Display SubPatch Level and

Render SubPatch Level settings, we can

enjoy the speed of low-resolution animation

meshes and the beauty of high-res render

meshes without having to think about or do

anything more than just press <F9>.

Just remember the credo of good 3D

modelers and animators everywhere: Your best work will come from using the absolute minimum number of “whatsits” needed to hold your “schiznit” in place.

· · · · M o d e l i n g 3 : S u b - Pa t c h O r g a n i c M o d e l i n g

Note

I can’t stress enough how cool it is to have a crowd of SubPatch Level 0 characters all on

screen at once and still have screen-refresh

rates that are actually conducive to ing (In 1996, by contrast, three low-res

animat-characters in Softimage slowed an R10K down to a mind-mangling crawl!)

This chapter shows how to create one of

those “one-minute wonders” that you’d see

at trade shows and the like It’s not

sup-posed to be spectacular; it’s just meant to

get you more comfortable with using

sub-patches to actually do something

1 Create a box with dimensions similar to

the one in Figure 8-1 (the Numeric

window is shown just in case you

would like to reproduce it exactly) Theimportant thing is that the box is cen-tered on the X axis and has twosegments along the Z axis

2 Activate Symmetry mode, and thencheck that your model is indeed cen-tered by clicking on some polys (orpoints) on one side If your model iscentered, the corresponding geometry

Figure 8-1

on the other side will also be selected.

(If your box isn’t centered, with

Sym-metry inactive, use Modify |

Translate | Center to center it on all

axes, and then reactivate Symmetry

mode.)

3 Select the rear two polys at the sides

(See Figure 8-2.)

4 Apply Smooth Shift with an Offset of

0 m, a Scale of 100%, and a Max

Smoothing Angle of 0º (You will see no

visible change in your model at thistime.)

5 Using the Stretch and Move tools,position these polys similarly to whatyou see in Figure 8-4 Don’t movethem off the sides of the ship; just

“squish” them a bit — these are thebases for what will become the wings

· · · · O r g a n i c M o d e l i n g E xe r c i s e 1 : “O n e - M i n u t e ” S p a c e s h i p

Figure 8-2

Figure 8-3

I bet you’re wondering when we’re going to

get to sub-patches Don’t worry, we’ll

acti-vate them for this model in just a bit I want

to make a point of how working with

sub-patches is almost exactly like working

with polys, the only differences being that

with sub-patches, you never have to worry

about anything being non-planar, and

how-ever you manipulate your mesh, you must

keep your sub-patches as quadrangles (or

triangles).

6 Next we’re going to use Bevel on only

the top rear poly Apply only an Inset(we’re exploring using a different tool

to do the same job) This poly is thebase of the tail (See Figure 8-5.)

7 Use Stretch and Move to get this polythe rest of the way to where it needs to

be (Remember, with Symmetry modeactive, you need to do your mousework on the positive side of the Xaxis!)

C h a p t e r 8 · · · ·

Figure 8-4

Figure 8-5

Figure 8-6

8 Now for the moment we’ve all been

waiting for — deselect everything and

press <Tab> to activate sub-patch

surfaces (It’s not much to look at, but

it’ll start looking better in a moment.)

Note

A trick you will eventually pick up on is the

“Space, two-tap.” (But why wait?)

Modeler has two primary selection modes:

Points and Polys You use <Space> to toggle

between them If you’re working with polys in

Polygon selection mode and want to view your

model as sub-patches without “letting go” of

the polys you currently have selected:

•Press <Spacebar> (you’ll be in Points tion mode).

selec-•Press <Tab> to activate sub-patches (if you have no selection defined for your points selection).

•Press <Spacebar> again.

You’ll be right back where you were, in gon selection mode, with the same polys selected Only now, your model is being viewed as sub-patches.

Poly-· Poly-· Poly-· Poly-· O r g a n i c M o d e l i n g E xe r c i s e 1 : “O n e - M i n u t e ” S p a c e s h i p

9 With the tail poly selected, use SmoothShift as you did before for the wingsand then position the new poly as yousee in Figure 8-8, making the tail fin.Once you’ve got your model matching

the figure, useSmooth Shift onthe poly again, andmove it just thebarest of microm-eters so its pointsaren’t directly ontop of the pointsfrom which itoriginated

Figure 8-7

Figure 8-8

(This has the effect of “flattening” the top

of the smooth shifted area, making the edge

of it nice and sharp This is one of the ways

you can make a sub-patch model have

“crisp” areas of definition It’s not quite as

elegant as setting a value of +100% for the

SubPatch Weight setting for the desired

geometry, but it is a popular trick Moving it

just that little bit means that the points

won’t get eliminated if you were to do a

Merge Points somewhere down the line.)

Note

For the rest of the book, whenever we smooth shift a sub-patch, let it be under- stood that it is with an Offset of 0, a Max Smoothing Angle of 0, and a Scale of 100%

— just as we’ve done for all the smooth shifts so far in this chapter.

10 Next, use the Smooth Shift and Movetools on the two wing polys to get thepreliminary shape of the wings

C h a p t e r 8 · · · ·

Figure 8-9

Figure 8-10

Figure 8-11