.\" 

.TH "LTVIEW" "1" "08/04/14" "RADIANCE" ""

.SH "NAME"

ltview \- view photometry of a light source

.SH "SYNOPSIS"

.B ltview

[

.B \-i

][

.B "\-b boxsize"

][

.B "\-o device"

]

input

.SH "DESCRIPTION"

.I ltview

renders a Radiance luminiare or IES photometry interactively using

.I rad(1).

.PP 

.I ltview

accepts exactly one Radiance object or IES photometry

file as input.  No input is taken from STDIN.  The

.I \-i

option tells it that the input file contains 

IES photometry rather then a Radiance description of a 

luminiare.  In this case, Radiance's

.I ies2rad(1)

is called with its default settings to convert the IES file into a 

Radiance object.

.PP 

Unlike

.I objpict(1)

or

.I objview(1),

no additional light sources are added to the scene, since it is

assumed that the object is a luminaire.

.PP 

.I ltview

relies on Radiance's

.I rad(1)

command to compile an octree using 

.I oconv(1)

and to call

.I rvu(1)

to display an interactive preview of the luminaire.

The luminaire, or output from 

.I ies2rad(1),

is moved so that its center is at world origin.

.I ltview

then generates an open box around the fitting that is ten times

as big as the largest axis\-aligned dimension of the fitting.

The \-y face of the box is left open so that 

the camera can look inside, facing +y.

The overall dimensions of the enclosing box may be overwritten with the

.I "\-b boxsize"

option.  Note that both the fitting and the box are always centred at the

origin.

.PP 

When

.I ltview

is run with the

.I \-i

option, i.e. the file is an IES photometry file,

then the dimensions of the luminaire and intesity of its 

output are determined by

.I ies2rad(1)'s

default settings.  If this is not acceptable, then it is best to run

.I ies2rad(1)

manually, and to feed

.I ltview

the hand\-crafted fitting, rather than the IES photometry.  In any case,

it is likely that the initial exposure within the 

.I rvu(1)

window window needs to be adjusted before the distribution of the fitting

can be fully appreciated.

.PP 

The default

.I rvu(1)

output device is

.I x11

on all platforms except for Windows, where it is set to

.I qt.

This may be overwritten with the

.I "\-o output"

option.

.SH "EXAMPLES"

To query available output devices

.IP "" .2i

rvu \-devices

.PP 

To visualise an IES file with the qt driver

.IP "" .2i

ltview \-o qt ABC123.ies

.PP 

To look at a typical fluorescent fitting that is modelled in millimeters

.IP "" .2i

ltview \-b 5000 XYZ_batten.rad

.SH "AUTHOR"

Axel Jacobs

.SH "SEE ALSO"

ltpict(1), ies2rad(1), oconv(1), rad(1), rvu(1)