Essential LightWave 3D- P6 pdf

The Sketch tool Create | Curves | Sketch was used to quickly draw the curve that was then lathed with the same settings as the disc in Figure 5-11.. With a Taper tool active, click in a

The Lathe tool lets you take something

you’ve created and “spin” it around to

cre-ate an object It crecre-ates geometry from

either polygons or curves (Lathe is

some-times called Sweep in other 3D packages.)

1 Create a two-dimensional disc

some-where to the left of X=0.

Note

In addition to using the Numeric window to

change the Lathe settings, you can drag the

root handle around to move the center of

the effect You can drag the rotation handles

to specify where you want the “lathing” to

start and stop.

Press the <Left Arrow> to reduce the

number of segments; press the <Right

Arrow> to increase the number of segments.

Note

Sometimes Lathe creates the new polys with their normals facing the “wrong” way Be sure to check this every time after lathing and flip the polygons if necessary (Even if you’re using a double-sided surface on your polys, it’s always a good idea to have your normals facing the “right” way.)

Figure 5-11

2 Select Multiply | Extend | Lathe to

activate the Lathe tool Click in theBack viewport, as shown in Figure5-12, and drag straight down (The axisyou are creating defines the anglearound which your disc will be

“lathed.”)

Figure 5-12: Multiply | Extend | Lathe activates the Lathe tool.

Figure 5-13: Lathe also works with splines (curves

— also known sometimes as

“rails”) to quickly create rather neat-looking chalices and other “turned” objects.

(The Sketch tool (Create |

Curves | Sketch) was used

to quickly draw the curve that was then lathed with the same settings as the disc

in Figure 5-11.)

Figure 5-14: The Offset field lets you “skew” the lathe operation, letting you create springs and

other nifty doodads! (Remember that you can enter a mathematical formula into any of

Under the Modify | Transform menu,

LightWave offers two kinds of tools that

taper your geometry Taper lets you control

the amount of effect on each axis of the

taper, depending on how much you move

your mouse up and down or left and right

Taper Constrain, on the other hand, affects

your geometry in both directions of your

taper at once (for instance, if you wanted a

Doric column to evenly taper as it rises)

With a Taper tool active, click in a Top

viewport to taper your selected geometry

Note

Taper, Twist, and Bend all work best when you have many segments along the effect’s axis of the geometry you are deforming.

as it extends along the Y axis Drag left orright, up or down to taper your object.(Technically, the Taper tool successivelyscales the selected geometry relative to thedistance of the selected geometry’s

bottom.)

Figure 5-15: The Taper Constrain tool in action.

Pressing <n> opens the Numeric

win-dow for Taper and activates a little gizmo

(seen on the “Base Object” in Figure 5-15)

to give you a visual interpretation of the

Taper tool’s effect Right-clicking and

drag-ging the gizmo’s ends will let you exactly

position and angle the tool’s effect

Through the Numeric window, you can

adjust the falloff of the effect to “sculpt”

how Taper affects your selected geometry

• The Falloff pop-up menu lets you

choose from several complex ways of

let-ting the taper effect dissipate through

space (We use Linear because it is what

you will most often use However, through

this pop-up menu, the tool can even

refer-ence the settings on a weight map that

you’ve created To find out more about

these falloff settings, explore the

Light-Wave manual.)

• The Shape buttons let you invert the

effect (so the bottom tapers instead of thetop), have the taper affect both ends atonce, or affect just the middle of theselected geometry

• The Presets pop-up menu gives you

quick access to four combinations for the

sliders below it that shape the curve of the

linear falloff (You can see examples of theeffect of changing these sliders in Figure5-15.)

• The Range of the effect defaults to

Automatic However, by right-clicking andmanipulating the gizmo, you are tellingLightWave that you want to specify a fixedangle and/or position for the effect Clicking

on Automatic releases your specified, fixedsettings

Twist

The Twist tool is something I don’t use all

that often, but when I need it, there’s

noth-ing else that can fit the bill like this tool can

Technically, it spreads out rotation through

your selected geometry in relation to how

far each bit is away from the effect’s root In

layman’s terms, it twists stuff The Twist

tool is accessed through Modify | Rotate

| Twist.

Twist also obeys the same kind of falloff

rules that Taper does By shifting the falloff

sliders, the twist in Figure 5-16 (on the

following page) begins gently from the

bot-tom, increasing as it reaches the top of our

We used Bend when making our flying text

logo in Chapter 3 It follows along the same

rationale as Taper and Twist

Figure 5-16: The twist axis is established

by clicking in a viewport, “spindling” the effect directly away from you in the viewport in which you clicked (Think of the axis around which you’d twist a tall stack of napkins, playing cards, or saltine crackers You establish this axis by looking straight down at the stack.)

Figure 5-17: Click and drag

in a viewport to bend your selection as if it were a car’s radio antenna and you were looking straight down the antenna at the effect’s axis.

if it’s created any planar polys.

non-Smooth Scale/Move Plus

Smooth Scale pushes your selection out

along each individual polygon’s normal by

the distance you enter in its input window

(It will pull your selection in if you enter a

negative value.) Unfortunately, Smooth

Scale has no real-time interface, which

makes its use less than intuitive That’s

why the Move Plus tool is such a welcome

addition to LightWave 8 Move Plus

fea-tures all of the functionality of the

traditional Move tool when using the left

mouse button However, when used with

the right mouse button, it performs a

real-time smooth scale

What if we wanted to make ThinGuy

(one of the characters in LightWave 3D 8 Character Animation) into “PlumpGuy”?

(Hey, anything can happen in production,right?)

I select the polys I want to push out and

then select Modify | Translate | More |

Move Plus By right-clicking and dragging

up, I can push the polygons out along theirnormals, essentially puffing it up Draggingdown pulls them back in I often use theMove Plus tool on a character’s fingers tomake them fatter or thinner

Note

Due to the way Smooth Scale and Move Plus operate, they can break the symmetry on your object Be sure to check symmetry after working with one of these tools.

Figure 5-18: ThinGuy.

Rail Extrude — Single Rail

Rail Extrude is a little like those

“Leather-man” tools that are a combination

screw-driver, pliers, scissors, awl, penknife, and so

on Rail Extrude is one little tool, but it

does a whole lot of things Let’s start with

one of its simple uses and move on from

there

Have you ever wanted to create one of

those “tunnel fly-throughs”? Follow these

steps:

1 Grab the Sketch tool, and draw a rail

(curve) you’d like to have your tunnel

follow (You can load mine, if you like

It’s had some points cut from it to help

smooth it out: Objects\Chapter05\

RailExtrude_Raw.lwo.)

Note

Notice the funky little diamond thing at one end of the curve in Figure 5-21 That is the

end I started sketching first This is the start

point of the curve, as far as LightWave’s Rail

Extrude is concerned The circle we create in just a moment should be right at this place if

we want the extrusion to follow this curve as

we intend.

You can switch the end LightWave thinks

of as its start point by flipping the curve the

same way you would flip a polygon (<f>).

Figure 5-20: Using Smooth Scale or Move Plus on an entire object can produce some interesting results.

(Remember Dig Dug?)

Figure 5-21

2 With the curve in a background layer,

create a disc and move it to the curve’s

start point In order to have it orient

properly along the curve, you will also

need to rotate it so that its normal is

like an extension of the curve’s line

(“Spinning” around the Perspective

viewport and touching up the rotation

where the normal is most out of

align-ment is the quickest way to get it

aligned well.)

Note

Carl Meritt’s AlignToRail plug-in, available

on the companion CD, will automatically line up your polygon to the start of the back- ground curve, making quick work out of an otherwise time-consuming process.

Note

If you want the extruded geometry to have

its normals facing out, then you want to

have the soon-to-be-extruded poly’s normal

facing away from the curve.

If you want the new geometry to have its

normals facing in, then the poly’s normal should be facing toward the curve.

Figure 5-22

3 Once you’ve got the polygon aligned,

Multiply | Extend | Rail Extrude

opens the Rail Extrude: Single window

It has the following options:

• Automatic segmentation will let

LightWave make its best judgment as

far as how many “slices” to make and

where they should be so the extrusion

most closely follows the curve

• Uniform Lengths lets LightWave

distribute its specified number of

seg-ments so they are all equidistant along

the curve’s length

• Uniform Knots tells LightWave

to distribute its specified number of

segments with relation to the

place-ment and number of knots (points) on

the curve

• Oriented tells LightWave to rotate

the poly, aligning it to the curve as it is

extruded

4 Accept the default settings shown inFigure 5-22 The disc is extruded alongthe curve (looking a little like the

ductwork from Brazil).

5 Save your object (Mine is Objects\

Chapter05\RailExtrude_1.lwo.)

6 With the layer that has the curve in it

in the foreground, select File | Export

| Path to Motion Save the motion

somewhere where you’ll have intuitive

access to it (Motions\Chapter5\

TunnelFly-Through.mot is what I

used) You will need to add “.mot” out the quotes) to the end of the file for Layout to see it; Modeler doesn’t do this automatically when you use Path to Motion.

(with-7 Now, use Send Object to Layout so

we can make a movie of our quickexample here

8 While in Layout, use <[> and <]> to

adjust the grid size so your extrudedobject fills the screen nicely

Figure 5-23

9 Select the camera and use File | Load

| Load Motion File Choose the

motion file you created in Step 6 of this

exercise

10 Change the end frame of the Frame

Slider to 160, and “scrub” the Frame

Slider along the timeline You will see

your camera move along the tube

(even though it won’t be “looking

where it’s going” yet)

11 Under Display Options, give yourself a

Viewport Layout of 2 Left, 1 Right.

Set the Top Left viewport to Camera

View and the Right viewport to Top

View and have it Center Current

Item (You can set the Bottom Left

viewport to whatever you’d like.)

12 With the camera still selected, press

<m> to bring up the Motion Options

window for the camera (See Figure

5-24.)

13 Under the Controllers and Limits tab ofthe Motion Options window, set bothHeading Controller and Pitch Control-

ler to Align to Path You can then go

back to the IK and Modifiers tab andadjust how much your camera “antici-pates” its motion by setting the Align

to Path Look-ahead field (It’s easiest

to use the slider button to the field’sright and “scrub” through your scene,making little adjustments so the cam-era gives you what you want.)

If your polygon normals are facing in, yourCamera viewport should be showing youwhat it’s like to be looking down that tun-nel (If they aren’t, just switch back toModeler, flip them, and return to Layout; ifyou’re working with the Hub active, whenyou get back to Layout, the polys will beflipped!)

Figure 5-24

Align to Path is a controller available only

for heading and pitch You will want to go

through your movie and, with General

Options | Auto Key Create | Modified

Channels selected, rotate your camera on

bank where it seems fitting (You can always

reload the motion file onto the camera if

you don’t like what you’ve done — so

explore and experiment!)

14 Open the Surface Editor, and onto your

tunnel’s surface, load in a preset with

some bump to it so you can see some

“nurnage” (that’s the industry’s

techni-cal term for “neat-bumpy-detail”) as

you’re flying down the shaft (I wasn’t

happy with any of the presets that

came with LightWave, so if you want to

use one of mine, load in Surfaces\

GrungyCement.srf.)

Spend some time lighting and surfacingyour tunnel scene Render a movie and seehow things look

If things move too quickly or too slowly,you may have to change the end frame ofyour movie and enter the Scene Editor toscale your keys

Figure 5-25: Just a quick F9 of the tunnel we just made.

Figure 5-26: You can scale the keyframes for objects in your scene using the Dope Sheet in LightWave 8’s Scene Editor Click on the first keyframe for your camera (denoted by a green bar), then, holding the <Shift> key, click on the last keyframe You can drag the yellow bars on either side of your selection to scale interactively or right-click and choose Numeric Time Scale from the pop-up requester to scale your selection by a specific percentage If you’re unhappy with the results, simply right-click again and select Undo.

If you would like to pull apart my scene for

this exercise, you can find it in the companion

files:

Scenes\Chapter_05\Tunnel_Fly-Through_F.lws.

In the scene, you’ll find a working example

of vector blur You’ll also see an example of a

trick using morphing to get a texture to

cor-rectly follow a twisting object.

There is no right way or wrong way to do

anything — so long as the way you do

some-thing works But you should always press

yourself to find a new angle on what you’re

currently doing, even if it is an idea as

well-used as a tunnel fly-through.

(The movie in Figure 5-27 came from

Ren-ders\Chapter05\Tunnel_Fly-Through.mov.)

Rail Extrude — Multiple Rails

Now how about “lofting”? Can LightWave

do lofting? Absolutely.

Note

Lofting is a term from CAD/CAM programs

that work almost exclusively in splines and

NURBs (non-uniform, rational B-splines) In

short, lofting is using splines to guide the

creation of a NURB surface.

LightWave will let you guide the extrusion

along multiple background curves You can

use this to create any level of mesh density,

from things that can be used as sub-patches

(very low density) to extremely sity meshes (for use in slowing even a Craysupercomputer down to PC Jr speeds).Say you wanted to create a strangelyergonomic hilt for some alien blade (SeeFigure 5-28.)

high-den-1 You would first create two curves that

“outlined” the shape of the desiredform (The start points should bewhere you intend to put the geometrythat will be extruded.)

Figure 5-27: A frame from my take on the fly-through.

2 Next, with the curves in a background

layer, create a shape you wish to be

extruded In this case, it is a standard

disc that is wider in X than it is in Z

Position it at the curves’ start points

with its normal facing out.

3 Activate Rail Extrude to bring up the

Rail Extrude: Multiple window It has

the following options:

• The Segments section allows you

to control how “dense” the extruded

mesh is (just like Rail Extrude with

only one curve in the background).

• Strength is a factor of how

“tightly” the extrusion will follow the

curves

• Oriented, as when rail extruding

with only one curve, “angles” the

extrusion as it follows the curves

• Scaling lets your extrusion

“expand” on all three axes in relation to

the distance between the two curves

Note

Using the Knots setting to determine ment placement means you must be a lot more careful when creating the curves you will be “lofting” along LightWave will try to

seg-distribute segments and orient them knot for

knot If your object’s silhouette must meet

an exact shape, have all your curves made with the same number of knots, and know that from the first knot to the last on all curves, LightWave will use them to deter- mine exact placement and angle of the extruded segments.

Figure 5-29

Figure 5-30: Using just the default settings for Rail

Rail Extrude: Multiple can create a lot of non-planar polys Check your work after using this tool.

Rail Bevel

Rail Bevel? Yep It’s a cool tool that lets you

specify the shape of the bevel (It’s easier

to show what it does than to try to explain it

in words.)

1 Make a simple rectangle

2 With your rectangle in a background

layer, use Sketch to quickly doodle a

shape that could be a molding joiningthe ceiling and walls of a house

Figure 5-31: You can use more than two curves to

shape your extrusion to get even more “organic”

shapes.

Figure 5-32: Again, using just the default settings,

we get something that looks even more like it was

“grown” than “machined.”

The points of the background layer are used

to guide Rail Bevel, not the curve itself So,

while you may be tempted to add points to

smooth things out, don’t Rail Bevel is

guided by the point order, the order in which

the points were created If you need more

detail in an area, put your curve in the

back-ground and create new points in a

“dot-to-dot” fashion along the entire curve, adding

in the new ones you need as you go.

3 With the curve in the background layer,

use Multiply | Extend | More | Rail

Bevel to turn the simple polygon into

an instant cornice piece Dragging up and down in a viewport will make the bevel wider or narrower; dragging right and left will make it taller or shorter.

(This seems backward to me, so I justuse the Numeric window for myreal-time rail bevels.)

Figure 5-34