Film "image"
    "integer xresolution" [512] "integer yresolution" [512] 
    "string filename" "caustic-proj.exr"

Integrator "sppm" "integer numiterations" 256
    "float radius" .25
    "integer maxdepth" 10

#Integrator "mlt" "integer mutationsperpixel" 200 "integer maxdepth" 10

LookAt 0 -4 5    0 0 -1   0 0 1
Camera "perspective" "float fov" [50 ]

WorldBegin

AttributeBegin
    LightSource "infinite" "string mapname" ["textures/grace-new_latlong.exr"]
AttributeEnd

AttributeBegin
    Material "matte"
    Shape "trianglemesh" "integer indices" [0 2 1 0 3 2 ]
        "point P" [-20 -20 -2   20 -20 -2   20 20 -2   -20 20 -2 ]
AttributeEnd

Material "glass" "float index" [1.5 ]
Shape "sphere" "float radius" 1.5  

WorldEnd