.\" 

.TH "LTVIEW" "1" "11/03/14" "RADIANCE" ""

.SH "NAME"

ltview \- view a light source

.SH "SYNOPSIS"

.B ltview

[

.B \-i

][

.B "\-r roomsize"

][

.B "\-o output device"

]

input

.SH "DESCRIPTION"

.I ltview

renders a Radiance luminiare or IES photometry interactively using

.I rad(1)

.  This program is merely a shell script that calls

.I rad(1)

to make an octree and view the scene interactively.

.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 file name given is 

an IES photometry file 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 and to call

.I rvu(1)

to display an interactive preview of the luminaire.

The default behaviour for

.I ltview

is to scale the luminaire or output from 

.I ies2rad(1)

so that the largest dimension of the fitting is unity, centered at the origin.

This scaled representation of the original fitting is then placed inside a 

square box 10 units in size.  The \-y face of the box is left open so that 

the camera can look inside, facing +y.

If it is desirable to keep the original luminaire in both its original size,

and its original location, the

.I "\-r roomsize"

option may be used to fix the room size to a certain

.I roomsize.

In this case, the size and location of the fitting is not adjusted, and

it is up to the user to decide on appropriate room dimensions.  Note that

when

.I \-r

and

.I \-i

are combined, 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.

.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 T5 fluorescent fitting that is modelled in millimeters

.IP "" .2i

ltview \-r 5000 XYZ_batten.rad

.SH "AUTHOR"

Axel Jacobs

.SH "SEE ALSO"

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