LightWave 3D 8 Texturing phần 7 potx

Standard Projection TechniquesIntroduction to Standard Projections When working with images for texturing, we have to define exactly how the image is to be placed projected onto the surf

Standard Projection Techniques

Introduction to Standard Projections

When working with images for texturing,

we have to define exactly how the image is

to be placed (projected) onto the surface of

the object, as no program is so intelligent

as to know exactly how to place an image

onto a surface without some coordinates

that tell it where to put the image and in

what manner the image should be applied

Even in the following image, we would

need to tell LightWave how to project this

texture straight onto the surface, even

though the placement may seem pretty

straightforward and obvious

Defining these projections involves a process called mapping, of which

there are a number of different types Mapping can be roughly divided intotwo main categories: standard projections and UV mapping Both offer a fewdifferent options for you to use, and are suitable for different situations

To use a real-life analogy, let’s assume that you make a sculpture andthen paint all the surface detail for that sculpture onto a piece of cloth Okay,

I know it would be a bit odd to not just paint directly onto the surface, butjust bear with me here! So you have your sculpture, and you have yourcloth, and now you need to figure out a way of wrapping the cloth onto thesculpture so that it looks right That is basically what mapping is Do youstick the cloth straight onto the front of the sculpture or do you strategicallyarrange the cloth onto it?

Figure 14-1

NOTE: You only have to specify a projection type for images and

for a few procedural textures, as gradients and most procedurals do

not require them due to the way that they are created.

What makes mapping really challenging is that in any situation, a number of

different approaches could be applicable The trick is to choose the best one,

and deciding on that requires a bit of planning and thought

To define the manner in which an

image will be projected onto a surface,

you need to choose an option from the

Projection list in the Texture Editor for

the channel into which you are placing the

image

As you can see, there are quite a few

choices

The first five options in the list — Planar, Cylindrical, Spherical, Cubic,

and Front — are standard (basic) projection types Standard projection types

offer perhaps the most straightforward methods of placing textures onto

your surface All you have to do is decide on the most appropriate method

for the object upon which you need to apply the texture, as the choice you

make will really depend on the shape and orientation of the surface with

which you are working

Planar Projection

Using Planar Projections

Planar is most probably the simplest method to use of all the standard

pro-jection types It is also possibly the most popular way of placing textures

onto surfaces Its simplicity can be deceiving though, because as

straightfor-ward as it is, this option is by no means simplistic or stunted in its actual

use In fact, you could almost say that as a general rule of thumb, if an object

cannot be planar mapped, then it cannot be mapped Sure, for some objects,

planar mapping the entire thing would be quite a task, but nevertheless it is

totally possible

Anyway, enough waffling about all that, as you are probably wanting to

know exactly what this simple method is!

Planar projection basically takes an image and projects it straight along

an axis, through the surface

292

Figure 14-2

Applying an Image Using Planar Projection

We apply an image by selecting Planar from the Projection list in the ture Editor, and then deciding which axis to project the image along byclicking on it in the Texture Axis option

Tex-This is demonstrated in Figure 14-4 As you can see, we take an imageand simply slap it straight onto the object along the same axis that the front

of the object is facing

So basically all you do is consider the direction in which the surface isoriented, and then apply the image along that axis In this case, the surface

of the object is facing sideways, so we basically apply the planar image alongthe x-axis

Figure 14-3

Figure 14-4

Likewise, if the surface faces upward or downward, we would apply it

along the y-axis, whereas if it were facing toward the front or back, we

would project along the z-axis

Planar Stretching/Dragging

Now if we look closely at the object with

the texture applied, we notice a slight

prob-lem Do you see how the texture stretches

through the length of the object, leaving

those rather unsightly lines? This is an

unfortunate problem that we always face

when using planar projections

Think of it like this Say we have a

block, and we have a nice little piece of

paper with a little design on it that is the

size of one of the block’s sides To apply

that paper design onto the block, we would

simply take the piece of paper and stick it

onto one side of the block

However, because the piece of paper is

flat and only the size of one side, we cannot

bend it around the edges of the block, so

instead it just stays stuck on the side that

we have glued it onto Similarly, a planar

projection cannot bend around edges; it

simply stays stuck on the face that you

have applied it to, along the parts of the

face that are oriented in the same direction

as the axis that you have projected it along Planar mapping obviously works

like a plane (hence the name), and as you probably know from modeling, you

cannot bend planes, because in reality that is impossible

So how does this explain the nasty

stretching shown in Figure 14-7? Well,

con-sider this If the design on this piece of

paper that you have stuck on your block

has been painted onto the paper, and the

paint is still wet, you could try to get the

design that is painted onto it onto the other

sides of the box by smearing the wet paint

along the edges of the paper along the

sur-rounding sides of the box This would look

Think of the pixels at the edge of an image being like the wet edges ofthat piece of paper Now does that make sense? Obviously the best way toget the design onto each side of the box would be to stick a piece of paperwith the design on it onto each side of the block, not by smearing the paint.

In LightWave, you could dothis by using a combination of acouple of different planar projec-tions along different axes, sothat the image could be pro-jected onto each side correctly

The easiest way to do thiswould be to assign different sur-faces to the block according totheir orientation and then sim-ply project the images

projec-This, however, is not the only method Instead of assigning separatesurfaces, you could also apply a single surface to the entire box and simplyset up three different layers within the Texture Editor, each with its appro-priate planar projection You could then use falloff (covered in Chapter 13) toensure that none of that nasty planar stretching is visible

So now we understand how planar mapping works on objects likeblocks, but what about uneven surfaces? Well, you can use planar mapping

on some irregular surfaces, but surfaces that are very uneven cause lems, because that horrible stretching that happened in the block examplebecomes visible In Figure 14-10, I have projected the dirt texture along they-axis, and as you can see, this works fine with the fairly flat surface, butwhen applied to the very irregular surface, we get stretching

prob-Figure 14-8

Figure 14-9

Although you could probably get away

with this sort of thing in a distance shot, it

will not suffice for objects that are close to

the camera

As you can see, the more the surface

slopes away along the projection axis, the

worse this problem becomes, as more

stretching appears

This makes planar mapping really

mostly ideal for flattish objects such as

walls, doors, floors, or any polygonal surface that is predominantly facing

toward one axis and does not have too much depth visible where stretching

would occur

Blending Planar Projections

As I mentioned at the beginning of this chapter, pretty much any object of

any type or structure can technically be planar mapped Sometimes,

how-ever, this requires you to use a number of different images projected along

different axes that you blend together using falloff in each texture layer that

needs a different projection axis, or by using gradients (especially with

weight maps) as alpha layers, or even alpha channels in the images

them-selves Sounds complex, but it is actually fairly logical and simple to

execute

Blending with Falloff

The most logical way of blending planar projections would be by using falloff

on each layer that needs to be blended, and then carefully positioning each

image into place so that it all works nicely

NOTE: For more detailed information on using the Falloff options

in the Texture Editor, please refer to Chapter 13.

Using the same irregular ground object from the previous example, all I

have to do is create two separate layers in the Texture Editor, each with the

296

Figure 14-10

Figure 14-11

dirt image in it One of the layers is projected along the y-axis, as before,while the other is projected along the z-axis The image that is projectedalong the y-axis will not have to have any falloff settings applied to it,because in this instance, it will be on the bottom layer, while the other layerwill blend with it from above.

But let’s do this step by step so thateverything is very clear

So, starting right at the beginning, Icreate one layer in the Texture Editor Fig-ure 14-12 shows the surface once again,with the image applied along the y-axisonly

Take a look at where the stretchingoccurs, and remember that this stretching

is happening along the surfaces that slopedownward, along the same axis the image

is projected along, which is the y-axis Inorder to cover up these areas, we need toapply something along the z-axis, so thatthese areas will no longer be visible

Now let’s add a second layer to theTexture Editor above the bottom layer, thistime with the same image projected alongthe z-axis This step of the process lookslike Figure 14-13

Yes, I know this looks wrong, but don’tworry! Once blended correctly, this imagewill cover up the stretching

along the z-axis

So how do we get thesetwo layers to blend togethercorrectly? Well, all I need to

do is add some falloff to thetop layer (the one that isprojected along the z-axis)and reposition it slightly

So what I do is set upsome falloff to the layer asshown in Figure 14-14

The percent of falloffrefers to percent per meter

of falloff, which means that100% falloff creates a linearfalloff to 0% at 1 meter

Figure 14-12: Texture applied to y-axis

Figure 14-13: Texture applied to z-axis

Figure 14-14

The falloff on the y-axis will prevent it from stretching along the bottom

of the object, while the falloff on the x-axis prevents the stretching from

appearing too much along the sides

I also shift the actual position of the image slightly upward (to make

absolutely sure that the image does not drag along the bottom of the object),

and remove all tiling options so that the

image does not repeat itself at all by

select-ing the Reset option in my tilselect-ing options

(see Chapter 13 for more information on

tiling images)

For the sake of this example, I have

hidden the bottom layer so that you can see

the way in which the falloff and

reposition-ing of this image has faded the image out

along the y-axis

As you can see, we have a nice fading

that will blend well with the bottom image

Notice that I did not fade it out completely

along the side and bottom, as this would

basically make the entire image disappear

When I switch the bottom layer back

on and render it, the stretching is covered

up by the top layer

Pretty nifty

Blending with Gradients

The next blending method we can try out is using gradients in conjunction

with weight maps This method is not always as effective as the falloff

method, depending on the model, but is nevertheless worth a mention

Although it requires a little more work, it is, in many ways, easier than the

falloff method, which can sometimes be a little confusing

For this method you simply create weight maps that will act as alphas to

place the images where you want them to be, and then create gradient

lay-ers over those image laylay-ers in the Texture Editor, with the appropriate

weight map set up as the alpha for that particular image Let’s examine this

process

Figure 14-17 shows the object and the three images that we wish to

apply to the object For the sake of simplicity I am using a very simple

object, a cube, but this principle could be applied to any type of shape Image

1 will be projected along the x-axis, Image 2 will be projected along the

z-axis, and Image 3 will be projected along the y-axis

First, I need to create a weight map for the object to determine where

the different images will be visible Now remember, once we create the

weight map and use it with the gradient, it will act as an alpha layer for the

298

Figure 14-15

Figure 14-16

image that we wish to placeonto the model This meansthat we must create theweight map with a nice solidarea of one particular value

to determine the area wherethe image will be visible So,

I start off by creating a newweight map and calling it

“texture image 1,” andselecting the areas where Iwant the image to be visi-ble I then assign a singlevalue, 100%, to thisselection

This area, which has now been assigned a value of 100% in this weightmap, can now be used as an alpha layer with Image 1, and the image willonly show through this particular part of the weight map

I now create a second weight map called “texture image 2” that will act

as the alpha for the second image I do exactly the same thing as for the firstone, except that for Image 2 I set the weight map’s value to 100% on theareas that lie along the y-axis

Figure 14-17

Figure 14-18

And once again, I create yet another weight map, “texture image 3,”

that has the 100% area located on the areas of the object that lie along the

z-axis

I now have three weight maps, each of which will act as an alpha layer

for its respective image when applied to the model I now switch to Layout

and begin to set up my surface

I first apply Image 1 to the color channel of the cube I set the projection

to Planar along the x-axis

300

Figure 14-19

Figure 14-20

As you can see, the projection is ing as per normal planar manner However,since we only want the image to show up

work-on the parts of the cube that lie alwork-ong thex-axis, I now create a gradient layer abovethe image to act as an alpha for it I set thegradient’s Input Parameter to Weight Map,and select the “texture image 1” weightmap I then create a key in the gradient at100%, and set the color of that key towhite I also create keys at 0% and 99%, and set the colors of those keys toblack I set the gradient’s Blending Mode to Alpha

This will now allow theimage to only show throughthe areas of the weight mapthat are 100%, as we can seewhen the cube is renderedagain See Figure 14-23

I now repeat these stepsfor the other two images,creating for each of them agradient that acts as an alphalayer with its correspondingweight map

Once all of that is done,

I have a cube with all threeimages placed on their cor-rect sides as shown inFigure 14-24

So, as you can see, this is actually a very easy way of placing imagesand controlling them, even though it requires a bit of extra work

Figure 14-21

Figure 14-22

Figure 14-23 Figure 14-24

Blending with Alpha Channels

While the weight map and gradient method provides a nice hands-on and

visual solution to creating alpha channels within Modeler for your textures,

you can, of course, also just create alpha channels within the images

them-selves Certain file formats, such as TGA, can support 32-bit image depth

that includes an alpha channel embedded in the image itself

To do this, all you really need to do is to

cre-ate a falloff along the edges of the image within

the alpha channel, as shown in Figure 14-25

As you can see, this alpha channel in the

image would show only the areas that are within

the white part of the alpha, so the edges of the

image would be invisible when applied to the

object

If we were to take three images and create

an alpha channel like this for each one, and could

stack them on top of each other in the

Tex-ture Editor on the surface of the cube from

the previous example, they would

automat-ically blend together without a problem

Figure 14-26 shows three different images,

each applied to a separate axis and blended

by using their own alpha channels

The only tricky thing about using this

method on an object like this is that the

images fade out along the edges of the

cube, showing the surface’s color beneath

it So just be sure to make the surface’s

color similar to the overall colors of the images

Cylindrical Projection

Using Cylindrical Projections

Well, you will be happy to know that cylindrical projections are really

straightforward You use them for mapping cylindrical objects — it really is

as simple as that Unlike planar projections that can be used for so many

dif-ferent occasions and in so many ways, cylindrical projections are there for

when you are texturing tubes, poles, spears, arms, legs, soda cans, and

any-thing else that is, well, cylindrical in shape

302

Figure 14-25

Figure 14-26

Applying an Image with Cylindrical Projection

To use a cylindrical projection for a ture, select the Cylindrical option fromthe Projection list in the Texture Editor

tex-Once you have selected this type,you need to choose an appropriate projec-tion axis from the Texture Axis options

Just like with the planar projections welooked at in the previous section, the axisthat you choose for the texture to projectalong depends on the orientation of theobject to which you are applying the tex-ture Upright cylinders would have thetexture applied along the y-axis, whereascylinders that are lying on their sideswould have the texture projected alongthe x-axis or z-axis, depending onwhether they are facing from side to side

or front to back respectively

Think of it as taking a piece of paperand wrapping it around a tube, because that is essentially what cylindricalmapping does, as demonstrated in Figure 14-29

“Capping” Cylindrical Objects

As you see, the actual use of this projection type is extremely logical Theonly problem that we really face with it, even when using it correctly, is thepinching that happens at either end of the cylinder, on the cylinder “caps.”This really cannot be avoided if the ends of the cylinder have the same sur-face applied

Of course, we can use a variety of methods to cover it up, such as usingfalloff or any of the other methods discussed in the previous section, or wecould simply assign a separate surface to the end faces

Figure 14-27

Figure 14-28

Figure 14-29

Figure 14-30 shows a method using

weight maps in combination with gradients

to control the visibility of the image on the

top This is using a single surface with the

gradient (together with the weight map)

being used as an alpha layer on top of the

image projected in a planar fashion along

the y-axis onto the top part

As you can see, it works quite nicely,

and it was really easy to set up All I did

was create a new weight map on the cylinder that had an initial value of 0%,

and then selected all the points along the top and bottom of the cylinder and

set them to 100%, as in Figure 14-31

I then use this weight map, together with a gradient, and set up the

gra-dient so that the image projected onto this section will only show in the

areas where the weight map has a value of 100% when the gradient layer is

placed above the image layer We obviously need to use this weight map to

avoid the planar stretching that we looked at in the previous section, which

would occur from the image on top being projected down the length of the

cylinder

Ensuring Seamless Mapping

It is important when working with cylindrical projections to bear in mind

that somewhere along the object the ends of the texture are going to meet

Because of this, you might want to ensure that the image can tile correctly if

you do not want any visible seam Tiling images is placing repeating

ver-sions of an image on a surface Ideally, in order to create a smooth look to

the surface, we would not want to be able to see where each copy of the

304

Figure 14-30

Figure 14-31

image ends within the pattern, because this would look rather odd These

visible edges are called seams and are generally to be avoided at all costs.

Obviously you are not always working with images that have to have allthe seams hidden, as some surfaces, like a soda can, might actually have avisible seam on the label However, when working with other types of sur-faces, especially organic surfaces, you have to make sure that the imagesare going to meet without any noticeable seams

Figure 14-32 demonstrates what happens when an image’s two sides donot match, resulting in a seam, as well as a correctly made image that tilesthe right way

As you can see in the example on the left, the image used as a texturehas sides that do not match up, resulting in an image that will not be seam-less when applied to an object Notice in the little block below the imageitself that when the image is placed alongside itself, you can see the separa-tions at the edge

In the example on the right, no seams are visible when using thisimage, as this particular texture is tileable because the edges are matched

Using Adobe Photoshop’s Offset Filter to Hide Seams

The easiest way to make sure that an image can be tiled is by using the set filter in Adobe Photoshop If you create an image that you wish to tile on

Off-a surfOff-ace, Off-all you hOff-ave to do is offset it Off-along the top Off-and one of sides, Off-andthen simply cover up the visible overlapping areas using airbrushing or thecloning tool Let’s take a look at Figure 14-33, which shows the image used

in the previous example that had unmatched sides

Now, we go to the Offset filter in Photoshop (Filters>Other>Offset),and offset it from the top and the right, both by 100 pixels We get the resultshown in Figure 14-34

Figure 14-32

As you can see, we now have a visible seam within the image itself All

we have to do now is hide it In this example, I just use the Rubber Stamp

(clone) tool See Figure 14-35

If we try tiling this image now, we will have no visible seams, as shown

in Figure 14-36

And if we were to wrap this around a cylinder, we would have no visible

seam either So that is a nice quick method of ensuring seamless textures!

NOTE: Refer back to Chapter 11 for more information on creating

and using seamless textures.

Using the Width Wrap Amount Option

The most astute of you may have noticed

that there is an option when using

cylindri-cal projections in the Texture Editor cylindri-called

Width Wrap Amount

306

Figure 14-33 Figure 14-34

Figure 14-35 Figure 14-36

Figure 14-37

The value you enter into this field determines the number of times thetexture is wrapped around the object to which it is applied So if, for exam-ple, you wanted to wrap an image around a cylinder five times, you wouldenter a value of 5 in this field.

Figure 14-38 shows the result of wrapping a texture a total of eighttimes around the cylinder

Obviously, this is great for adding any repeating details without having

to actually make one big image that includes the repeating, especially sincesmaller images use less memory In a case like this, it is beneficial to usethe simplest, smallest image that you can get away with Of course this isalso a quicker method than creating a long image with the stripes repeatedeight times

Setting your width wrap correctly is important also for preventing anill-sized image from becoming hideously stretched if it wrapped 360° around

an object that the image is technically too small for Increasing this amountwould therefore reduce this stretching by repeating the image more timesalong those 360°, thereby making each repeat of the image cover less space,and therefore distort less

Cylindrical Projection Tutorial: Applying a Label to a Soda Can

This tutorial briefly demonstrates the process of applying a label to a can ofsoda

1 Open Modeler and load the 4.1.3-sodacan.lwo object from the companionCD-ROM Notice that the can has two separate surfaces applied to it:one surface for the label and one surface for the metal parts

Figure 14-38

2 Open the Surface Editor (Ctrl+F3), and

go to the label texture Click on the T

button next to the Color channel to

open up the Texture Editor

3 Go to the layer list and click where it

says “(none).” By default, all new

lay-ers created when the Texture Editor is

first opened are image layers, so you do

not have to specify that this is an image

layer Notice that the default projection

type is always Planar Click on the

Pro-jection drop-down button and select

Cylindrical Leave the Width Wrap

Amount option that appears at 1.0

4 Click on the Image drop-down button, and select Load Image Find the

4.1.3-sodalabel.jpg image on the companion CD-ROM and load it

As you can see, the image looks a little strange on the can, but we will

fix that in a moment

308

Figure 14-39

Figure 14-40

Figure 14-41

5 Go to where it says Texture Axis and

select Y by clicking on that button Thisnow projects the image down the length

of the object (its y-axis) in a cylindricalfashion

6 Now just click on the Automatic Sizing

button, and hey, presto! The image fitsperfectly onto the soda can as it should

That looks much better

Figure 14-42

Figure 14-43

Figure 14-44

You now have a cool-looking soda can that you can do with as you wish.

Spherical Projection

Using Spherical Projections

As its name suggests, this mapping projection type is for objects that are

more or less spherically shaped, or even perfect spheres (of course!) So

when it comes to mapping planets, balls, and sometimes also certain kinds

of heads, this is the projection to use

The way it basically works is almost identical to the way that cylindrical

mapping works, except that it wraps from both poles (the top and bottom

points of the model), creating a single seam along the axis of the model

This means that the image you are using will meet up not only along the

seam but also at both poles

The one thing that sometimes makes this projection type a little tricky

to work with is the way in which textures applied shrink toward the poles

on the objects Naturally, you can always work around this to compensate

for it, but it can be a little annoying at times

Figure 14-46 demonstrates this shrinking that occurs toward the poles

of the object

You compensate for this effect by altering the image, stretching the top

and bottom parts of the texture to compensate for their shrinkage once

applied Of course this sort of alteration might not always be entirely

neces-sary, as you may find that when working with textures for things like

310

Figure 14-45

Figure 14-46

planets, this shrinking may not actually be all that noticeable, as shown inFigure 14-47, which uses a totally unaltered rectangular map of the world as

a texture

Applying an Image with Spherical Projection

To wrap an image spherically around anobject, simply select the Spherical optionfrom the Projection list in the TextureEditor

You then select an appropriate axisalong which you wish to project theimage Most spherical mapping situationsuse the y-axis

You’ll notice that we also have options called Width Wrap Amount andHeight Wrap Amount when using spherical projections Like the WidthWrap Amount for cylindrical projections, here this value simply determinesthe number of times that the image is repeated as it is wrapped around thewidth of the model The Height Wrap Amount value determines the number

of times that the image is repeated along the length of the object (asopposed to its breadth) These values basically work as tiling options for thistype of projection

If we change each of these values to 4.0 using our world image, the way

in which these values work is clearly illustrated In Figure 14-50 you cansee that the image is repeated four times around the width and four timesalong the height of the sphere For most situations, you’ll find that the value

of 1.0 is most appropriate

Figure 14-47

Figure 14-48

Figure 14-49

Ensuring Seamless Mapping

As with the cylindrical projections that we

looked at in the previous section, spherical

projections also have the risk of visible

seams on the axis along which we have

projected the image

This means that generally we should

always try to ensure that the edges of the

image will meet seamlessly

Refer back to the previous section on

cylindrical mapping and review the

tech-nique using Adobe Photoshop’s Offset filter for correcting this

However, when dealing with spherical mapping, not only do we have to

watch for seams along one side of the object, we also have to be aware of

how the image looks when it meets up at the poles

Using Adobe Photoshop’s Polar Coordinates Filter to

Check Seams

A quick and easy way of checking to see how the image will look when

applied spherically is to use Photoshop’s Polar Coordinates filter

This filter is found under the Distort filters in Photoshop Use it only to

check your image, as leaving the filter applied to the image will mess up the

image, making it no longer useful for our purposes

Basically what you do is open the

fil-ter’s panel and ensure that the Rectangular

to Polar option is selected The little

pre-view window will show you a decent

representation of how the image will more

or less behave when wrapped spherically

around your model in LightWave

You can use this to ensure that the

image is seamless at the poles In Figure

14-52, we can see that the Earth image has

312

Figure 14-50

Figure 14-51

Figure 14-52

no problems as the two poles (the two polar regions) meet up with no ble seams.

visi-On the other hand, if we take a look at an image that has visible seams

in it, these seams will show up when looking at the preview pane in the ter’s panel

fil-As you can see, the seam is clearly visible Using this as a guide tocheck our progress, we can then use the Offset filter technique and lots ofClone Stamping and Healing Brush work to eliminate the seam

Spherical Mapping Tutorial: Applying a Texture to a Planet

What better way to demonstrate the use of spherical mapping than to do atutorial on planet texturing?

1 Load the 4.1.4-planet_tutorial.lws scene from the companion CD-ROM.You should see a scene that has a planet object consisting of two layers:planet surface and planet atmosphere See Figure 14-54 on the followingpage

2 Open the Surface Editor (Ctrl+F3), and go to planet surface Click onthe little T button to open its Texture Editor, and set up the default tex-ture layer as follows: Load the 4.1.4-planet_color.jpg image from theCD-ROM and select Spherical as its projection type Select Y as the axis,and set its Scale settings to 1.9 m for each axis Leave the Width WrapAmount and Height Map Amount at 1.0 each Your Texture Editor win-dow should look like Figure 14-55

Figure 14-53

3 We want to add a little luminosity to the planet just to give its lit side a

little more definition Go back to the Surface Editor and open the planet

surface’s Luminosity Texture Editor Set up the default layer that is

cre-ated as a gradient using Light Incidence as its Input Parameter Select

the light in the scene as the light that will affect the gradient

4 Now let’s create some keys in the gradient so that we get the right look

on the planet surface Select the key that is automatically created at the

top of the gradient, and change its Value to 0% This ensures that areas

that are facing away from the light will not appear luminous Create a key

at the very bottom of the gradient (make sure that the key is directly on

314

Figure 14-54

Figure 14-55