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Streak Lens Effect 249
to it. Effects ID’s are applied in the materials
editor by assigning the material one of the Material
Effects channels that are available. The Lens Effect
will only be applied to areas of the geometry where
that part icular ID is present.
Note: In many instances, you may want to apply
different Lens Effects settings to different pieces
of geometry or ID’s. To accomplish this, add
additional Lens Effects entries to the Lens Effects
Parameters list. Then set each different Lens Effect
entry to affect a different Effect or Object ID and
proceed.
Unclamped—An unclamped color is brighter than
pure white (255,255,255). The s oftware keeps
track of these "hot" areas which tend to show
up when your scene contains bright m etallic
highlights or explosions. This s pinner lets you
determinethelowestpixelvaluethattheLens
Effect is applied to. Pure white has a pixel value of
1. When this spinner is set to 1, any pixels with
a value above 255 will be glowed. You can invert
this value by clicking the I button to the right of
the spinner.
Sur f Norm—Applies the Lens Effect to part of
an object, based on the angle of the surface
normal to the camer a. A value of 0 is coplanar, or
parallel to the screen. A value of 90 is normal, or
perp endicular to the screen. If you set Surf Norm
to 45, only surfaces with normal angles greater
than 45 degrees wi l l be glowed. You can invert this
value by clicking the I button to the rig ht of the
spinner.
Whole—Applies the Lens Effect to the w hole scene,
notjustaparticularpieceofgeometry. This,in
effect, makes each pixel i n the scene a potential
Lens Effect source. The areas of the scene that have
the Lens Effect applied to them are determine d by
thesettingsintheImageFiltersgroupbox.
Alpha—Applies the Lens Effect to the alpha
channel of an image. The transparency of an alpha
channel is interpreted opposite that of the Mask
channel. Range=0 to 255.
ZBufferHiandLo—Highlights objects based on
their d istance (Z-Buffer distance ) from the camera.
The Hi value is the maximum distance and the Lo
value is the m inimum. Any objects between these
two Z-Buffer distances w ill be highlighted.
Image Filters group
Filters the Image Sources selections to let you
control how the Lens Effect is applied. For
example, you can have ten spheres in your scene,
each w ith the same O bject ID, but different colors.
If you set the Image Source as the Object ID of the
spheres, which selects all of the spheres, these w ill
be the only objects in the scene that Lens Effects
will apply an effect to.
However, now that Lens Effects knows where the
pixels are that effects
can be applied, it needs to
know which ones to actually apply the effec t to.
LensEffectsusesthefiltercontrolstofindout
whichsourcepixelstoapplytheeffectto.
All—Selects all source pixels in the scene and
applies the Lens Effect to them.
Edge—Selectsallsourcepixelsalongaboundary
edge and applies the Lens Effect to them. Apply ing
a Lens Effect along the edges of objects produces
asofthalothatexistsonbothinsideandoutside
edges of you r object.
Per im(et er ) A lp ha —Applies the Lens Effect only
to the perimeter of an object based on its alpha
channel. Selecting this option applies the effect
only on the outside of an object without any
spill on the interior. Whereas filtering by Edge
produces a spill onto the object, Perimeter Alpha
keeps all of the edges clean because it relies on the
scene alpha channel to derive its effect.
Per im(et er )—Applies the Lens Effect only to the
perimeter of an object based on Edge interference.
Although not as precise as Perimeter Alpha, you