Update scene glass Integrator

glass/p3d_glass.pbrt

@@ -3,7 +3,7 @@
 LookAt 3.592741 20.556787 4.337005 3.423012 19.583931 4.179706 -0.026954 -0.154972 0.987551
 
 Sampler "random" "integer pixelsamples" [ 64 ]
-Integrator "bdpt" "integer maxdepth" [ 65 ]
+Integrator "volpath" "integer maxdepth" [ 65 ]
 
 Camera "perspective"
 	"float fov" [7.327086285904825]