##RenderMan RIB-Structure 1.0
version 3.03

###########################################################################
#
# This RIB file give a demonstration of the use of automatic shadows
# which can be attenuated by opacity of individual objects.
#
# Casting shadows:
#    By default, light sources do not cast shadows.  The following RIB
#    sets a nonstandard attribute which causes any subsequently declared
#    light sources to automatically cast shadows using ray tracing:
#              Declare "shadows" "string"
#              Attribute "light" "shadows" "on"
#              LightSource ....
#    This attribute "affixes" itself to the lightsource when it's
#    declared.  Note that it can be pushed and popped by AttributeBegin/End,
#    just like any other attribute.
#
# Occluder options:
#    When a light source casts shadows, by default the object casts a
#    shadow which blocks out light according to the Opacity in effect
#    when the object was declared.  For some complex objects (like the
#    ones in this scene), the surface shader needs to be evaluated before
#    the renderer can know exactly what the opacity needs to be.  This
#    is slower than the default, and only needs to be done when the 
#    surface shader causes the opacity to change across the surface.  In
#    this case, the proper attribute to set is:
#           Declare "casts_shadows" "string"
#           Attribute "render" "casts_shadows" "shade"
#
# These attributes are all described in the "BMRT User Guide".
#
###########################################################################

Option "searchpath" "shader" [".:../shaders:&"]

# if the next line contains "file" instead of "windows", the image would be
# stored in "assn2.tif"
# "rgb" refers to color model
Display "assn2.tif" "windows" "rgb" "compression" "none"

# image size and aspect ratio (width/height).
Format 240 180 1

# how many samples to take per pixel; used to control aliasing
PixelSamples 1 1

# projection type and camera field of view angle
Projection "perspective" "fov" 45

# Default camera is at world coordinate origin pointing down +z
# The following transformations place the camera in the world.
Translate 0 -2 8
Rotate -110 1 0 0


WorldBegin

# Our scene has two light sources, one ambient, one distant point light.
# These shaders are located in the Pixar shader directory
LightSource "ambientlight" 1 "intensity" 0.5

LightSource "distantlight" 1 "from" [0 1 4] "to" [0 0 0] "intensity" 0.8

# Declare "brickwidth" float
# Declare "brickheight" float
# Declare "mortarthickness" float

# The following section describes the floor, a polygon whose surface shader
# is the "brick" shader.  The values following "brick" are changing the
# the default values of the "brick" shader's instance variables.
#
# Note polygon vertices are given in a counterclockwise order.
AttributeBegin
  Color  [ 1.0 1.0 1.0  ] 
  Surface "brick" "brickwidth" 1.0 "brickheight" 0.25 "mortarthickness" 0.05
  Polygon "P"  [ -5 -5 0 5 -5 0 5 5 0 -5 5 0  ] 
AttributeEnd

# The following section describes the wall, a polygon whose surface shader
# is the "wood2" shader.  Default values of the "wood2" instance variables 
# are used.
AttributeBegin
  Color  [ 1.0 1.0 1.0  ] 
  Surface "wood2"
  Polygon "P" [ -5 -5 5  5 -5 5  5 -5 -5  -5 -5 -5    ] 
AttributeEnd

# The following section describes the sphere,  whose surface shader
# is the "plastic" shader.  Default values of the "plastic" instance variables 
# are used.  Notice the sphere has been translated before placement.  The
# sphere parameters are the radius, lowest z value to use, highest z value
# to use, the number of degrees around.  In this case we have a complete
# sphere rather than a hollow hunk of cheese.  For example, try 
# Sphere 1 -.5 .5 270
AttributeBegin
  Translate 0 0 2
  Color [1 1 .06]
  Surface "plastic"
  Sphere 1 -1 1 360
AttributeEnd

WorldEnd