Scene for my reproduction rendering of Fig. 1 of Walter et al. 07 paper, scene format is for tray_rust. Grab the images from imgur http://imgur.com/a/zh4C9

water07.json

{
	"film": {
		"width": 1024,
		"height": 1024,
		"samples": 1024,
		"frames": 1,
		"start_frame": 0,
		"end_frame": 0,
		"scene_time": 0,
		"filter" : {
			"type": "mitchell_netravali",
			"width": 2.0,
			"height": 2.0,
			"b": 0.333333333333333333,
			"c": 0.333333333333333333
		}
	},
	"camera": {
		"fov": 30,
		"transform": [
			{
				"type": "translate",
				"translation": [0, 10, -45]
			}
		]
	},
	"integrator": {
		"type": "pathtracer",
		"min_depth": 6,
		"max_depth": 10
	},
	"textures": [
		{
			"type": "image",
			"name": "rear_wall_texture",
			"file": "walter-etal-background.png"
		},
		{
			"type": "image",
			"pixel_format": "f32",
			"name": "earth_roughness",
			"file": "roughness_map.png"
		},
		{
			"type": "image",
			"pixel_format": "f32",
			"name": "color_earth_roughness",
			"file": "map-color-roughness.jpg"
		},
		{
			"type": "image",
			"name": "color_earth",
			"file": "color-map.jpg"
		}
	],
	"materials": [
		{
			"type": "matte",
			"name": "white_wall",
			"diffuse": [0.740063, 0.742313, 0.733934],
			"roughness": 1.0
		},
		{
			"type": "matte",
			"name": "rear_wall",
			"diffuse": "rear_wall_texture",
			"roughness": 1.0
		},
		{
			"type": "matte",
			"name": "red_wall",
			"diffuse": [0.366046, 0.0371827, 0.0416385],
			"roughness": 1.0
		},
		{
			"type": "matte",
			"name": "green_wall",
			"diffuse": [0.162928, 0.408903, 0.0833759],
			"roughness": 1.0
		},
		{
			"type": "plastic",
			"name": "plastic_earth",
			"gloss": [1, 1, 1, 1],
			"diffuse": "color_earth",
			"roughness": "color_earth_roughness"
		},
		{
			"type": "rough_glass",
			"name": "glass_earth",
			"reflect": [1, 1, 1, 1],
			"transmit": [1, 1, 1, 1],
			"eta": 1.52,
			"roughness": "earth_roughness"
		}
	],
	"objects": [
		{
			"type": "group",
			"name": "walls",
			"transform": [
				{
					"type": "translate",
					"translation": [0, 12, 0]
				}
			],
			"objects": [
				{
					"name": "back_wall",
					"type": "receiver",
					"material": "rear_wall",
					"geometry": {
						"type": "plane"
					},
					"transform": [
						{
							"type": "scale",
							"scaling": [15, 12, 1]
						},
						{
							"type": "translate",
							"translation": [0, 0, 16]
						}
					]
				},
				{
					"name": "left_wall",
					"type": "receiver",
					"material": "red_wall",
					"geometry": {
						"type": "plane"
					},
					"transform": [
						{
							"type": "scale",
							"scaling": [20, 12, 1]
						},
						{
							"type": "rotate_y",
							"rotation": 90.0
						},
						{
							"type": "translate",
							"translation": [-15.0, 0, 0]
						}
					]
				},
				{
					"name": "right_wall",
					"type": "receiver",
					"material": "green_wall",
					"geometry": {
						"type": "plane"
					},
					"transform": [
						{
							"type": "scale",
							"scaling": [20, 12, 1]
						},
						{
							"type": "rotate_y",
							"rotation": -90.0
						},
						{
							"type": "translate",
							"translation": [15.0, 0, 0]
						}
					]
				},
				{
					"name": "top_wall",
					"type": "receiver",
					"material": "white_wall",
					"geometry": {
						"type": "plane"
					},
					"transform": [
						{
							"type": "scale",
							"scaling": [15, 20, 1]
						},
						{
							"type": "rotate_x",
							"rotation": 90.0
						},
						{
							"type": "translate",
							"translation": [0.0, 12, 0]
						}
					]
				},
				{
					"name": "bottom_wall",
					"type": "receiver",
					"material": "white_wall",
					"geometry": {
						"type": "plane"
					},
					"transform": [
						{
							"type": "scale",
							"scaling": [15, 20, 1]
						},
						{
							"type": "rotate_x",
							"rotation": 90
						},
						{
							"type": "translate",
							"translation": [0.0, -12, 0]
						}
					]
				}
			]
		},
		{
			"name": "light",
			"type": "emitter",
			"material": "white_wall",
			"emitter": "area",
			"emission": [1, 0.772549, 0.560784, 60],
			"geometry": {
				"type": "rectangle",
				"width": 6,
				"height": 6
			},
			"transform": [
				{
					"type": "rotate_x",
					"rotation": 90
				},
				{
					"type": "translate",
					"translation": [0, 23.8, 0]
				}
			]
		},
		{
			"name": "sphere",
			"type": "receiver",
			"material": "glass_earth",
			"geometry": {
				"type": "sphere",
				"radius": 7
			},
			"transform": [
				{
					"type": "rotate_x",
					"rotation": -90
				},
				{
					"type": "rotate_y",
					"rotation": -195
				},
				{
					"type": "translate",
					"translation": [0, 8.5, 2]
				}
			]
		}
	]
}