Light Fog, Fluids, and Another Look at Materials ◾ 267
the glass cup. e attribute to note is the Reection Color, which has been set to a darker
but so blue.
The Background
As we have seen earlier, we need a background to properly render glass. In this scene we are
using a granite from the Maya materials in the Hypershade, shown in Figure9.32. e attri-
butes of the granite have been changed. e Color has been changed to a yellow. eCell
Size of the granite has also been increased to remove the speckled look we get from the
default granite. (is attribute is not shown in the gure, but is available on the granite1
tab of the attributes for the granite material.) Also, notice that when the granite texture was
created, there was no corresponding material made. is does not happen until the texture
is assigned to an object. Only then does the granite material appear in the Hypershade.
Rendering Settings
In the mental ray settings, the Reections, Refractions, and Max Trace Depth values have
been cranked up (see Figure9.33). Global Illumination and Final Gathering are also turned
on (see Figure9.34).
FIGURE 9.27 Emitter attributes. FIGURE 9.28 Container attributes.
268 ◾ 3D Animation for the Raw Beginner Using Maya
FIGURE 9.29 Glass material.
FIGURE 9.30 Glass material attributes. FIGURE 9.31 Attributes assigned to the glass.
Light Fog, Fluids, and Another Look at Materials ◾ 269
e scene was run for a couple of hun-
dred frames to generate the two particle
eects. On my 17-inch MacBook Pro with
a quad-core i7 in it, the rendering of one
frame took about three minutes. We see the
result shown in Figure9.35.
USING LIGHT FOG AND GLOW
TO CREATE A NIGHT SCENE
Maya provides several canned eects. We
are going to look at two of them. One is
fog, an eect that can be assigned to a
light. e other is glow, an eect that can
turn the surface of an object into a light
source. is is an important concept in 3D
modeling and rendering, and one that has
grown in popularity recently. As we have
discussed, materials, lights, and rendering
are all closely bound together, and if you
FIGURE 9.32 Granite material.
FIGURE 9.33 is shows mental ray settings.
FIGURE 9.34 With global illumination and
nal gathering.
270 ◾ 3D Animation for the Raw Beginner Using Maya
use an outside renderer, you oen want to make
use of the materials and lights supplied by that ren-
derer. And it is becoming more common to nd
materials that are self-illuminating and therefore
do not require the introduction of explicit lights
into a scene.
Also, if you ever want to experiment with dif-
ferent materials/lights/rendering packages, there
is a thriving market for plug-ins to SketchUp, a
popular vector drawing program that can be used
to create 3D models. It has its own materials and
lights, but it does not come with a native renderer.
I have used Maxwell, LightUp, Renditioner, V-Ray,
Shaderlight, Indigo, and Twilight. Some of these are Mac only or Windows only. ey
tend to come with their own lights and materials and add dramatically to the visual
impact of SketchUp models.
Fog
Maya has an effect that allows us to attach fog to a light. To do this, Maya takes a stan-
dard light (but not ambient or directional light) and adds a volumetric (i.e., volume-
based) material to the area lit up by the light. We can then adjust the properties of
that volume to simulate fog. This effect is computationally intensive and although
Maya does not implement this with a particle emitter, the visual effects and the ren-
dering time are similar. The difference is that the fog is static while a particle effect is
dynamic, with the particles moving and changing their light properties from frame to
frame.
A Sidewalk and Street Scene with Fog
In Figure9.36, we see the street scene built in Chapter 5. In Figure9.37, we are in the
Hypershade window and have chosen:
Create → Volumetric Materials → Light Fog
In Figure9.38, we middle mouse button click and hold on the light fog material in the
Hypershade, and then drag it to the Light Fog attribute inside the Light Eects tab of
the point light’s Attribute Editor. is is the light that sits inside the street light orb on
the le side of the scene. We drop the light fog in the black box and hit the Return key.
Figure9.39 shows the adjustments made to the other attributes under the Light Eects
tab; in particular we have cranked the Radius way up and have assigned a small value
for Fog Intensity.
We then go to the Hypershade and select the light fog material. As in Figure9.40, its
attributes appear in the Main Window. e color is set to white and the density of the fog
is set to a very low value.
FIGURE 9.35 (See p. CI-3 of Color
Insert) Stylized glass and bottle
render.
Light Fog, Fluids, and Another Look at Materials ◾ 271
FIGURE 9.36 Street scene.
FIGURE 9.37 Light fog creation.
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