#
# Can someone tell me why this scene produces something different to what I expect.
# Luxrender is a left handed coordinate system as follows. +Z axis into screen.
#
#    +'ve Y axis
#    |
#    |
#    |   /+'v Z axis
#    |  /
#    | /
#    |/
#   -+-----------  +'ve X axis
#   /|
#
# When I place the camera at (0 0 -50) which is-Z axis facing origin and 
# place a disc object at (-40 0 0)
# Why does the disc appear on right of image not the left ?
# It also seems to me that the limited angle of disc is produce a mirror of the
# expected pie slice missing that i would expect.
# I am missing something simple but cant identify it...
# Maybe im just missing some aspect of left handed coordinate systems ?
# I get what I expected if i make the Up vector for camera (0 -1 0) 
# but i dont understand why thats needed.
#

PixelFilter "mitchell" "float xwidth" [2] "float ywidth" [2]
Sampler "lowdiscrepancy" "bool progressive" ["true"] "integer pixelsamples" [4]
Film "multiimage"
	"integer xresolution" [400] "integer yresolution" [400]
	"string ldr_filename" ["ex01-material-uber.tga"]
	"integer ldr_displayinterval" [4]	# 4 is a low display interval
	"integer ldr_writeinterval"   [4]	# 4 is a very very low save interval
# Look at origin from negative z axis
LookAt 0 0 -50  0 0 0  0 1 0			# ex ey ez  lx ly lz  ux uy yz
#LookAt 0 -50 0   0 0 0  0 0 1			# ex ey ez  lx ly lz  ux uy yz
Camera "perspective" 					# NOTE: default "float fov" [90]

WorldBegin

AttributeBegin
	CoordSysTransform "camera"	# change to the camera coordinate system.
	LightSource "distant" 		# white light at camera facing postive z same as camera. 
				"point from" [0 0 0] "point to"   [0 0 1]
				"color L"    [1 1 1]
AttributeEnd

AttributeBegin
	Texture "checksRB" "color" "checkerboard" 
			"float uscale" [4] "float vscale" [2] 		# checkboard u around the axis, v is radial
			"color tex1" [1 0 0] "color tex2" [0 0 1]	# Red Blue

AttributeBegin
	Translate -40 0 0
	Material "matte"
		"texture Kd" "checksRB"
	Shape "disk" "float radius" [20] "float height" [0] "float phimax" [330]
AttributeEnd

AttributeEnd

WorldEnd