9

Matte/Shadow Material 1585
Creating a matte object for casting shadows against a
background image
Matte/Shadow materials can also have reflections.
Note: The Matte/Shadow effect is v isible only when
you render the scene. It isn’t visible in viewports.
Pr ocedur es
To r ender obj ects sea mlessl y a gai nst a back groun d
envir onment:
There are three ways you can render objects to
blend seamlessly into a background environment:
1. By assigning a Matte/Shadow Material
2. By assi gning a 100% self-illuminated diffuse
texture to an object using Camera Mapping
3. By assi gning a 100% self-illuminated diffuse
texture using Environment/Screen project ion
UsethePlateMatch/MAXR2.5antialiasing
whenever you are trying to match foreground
objects with an unfiltered background, or trying
to match the antialiasing qualities of the 3ds Max
2.5 renderer. S ee the description of Antialiasing
Filter in the description of the Default Scanline
Renderer (page 3–38).
Ex ample: To see the eff ect of Af fect Al pha and Ma tte
Reflection:
1.
Create a scene with one or more objects on a
box platform, and one or more shadow-casting
spotlights.
Tip: Ifyouuseonlyonespotlight,increaseits
Multiplier value.
2. Assign a Matte/Shadow m aterial to the box, and
render the scene with default Matte/Shadow
parameters (Opaque Alpha is on, and Affect
Alpha is off).
3. In the rendered frame window (page 3–5) that is
displayed, click Display Alpha Channel.
The objects all appear as white silhouettes,
including the platform.
4. On the Matte/Shadow Basic Parameters rollout,
turn off Opaque Alpha, a nd turn on Receive
Shadows and Affect Alpha.
5. Press F9 (Render Last (page 3–25) ).
Thesilhouetteoftheboxnolongerappears,but
the other objects and their shadows appear.
6. On the Matte/Shadow Basic Parameters rollout,
clicktheMapbuttonintheReflectiongroup,
and use the Material/Map Browser (page
2–1412) to assi gn a Flat Mirror (page 2–1695)
map to the box’s material.
7. Press F9 (Render Last (page 3–25) ).
8. In the rendered frame window, turn off Display
Alpha Channel.
The reflections of the objects appear on the box,
even though the b ox itself is invisible.