ltpict − render a four−view image of a light source
ltpict [ −i ][ −d dimensions ] input
ltpict is a script that renders a four−view HDR image of a Radiance luminaire or IES photometric file. The −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 ies2rad(1) is called with its default settings to convert the IES file to a Radiance object.
The four projections presented are the lower hemisphere (displayed in the upper left quadrant), the upper hemisphere (upper right), the C0−C180 plane (lower left) and the C90−C270 plane (lower right).
Only one Radiance luminaire description or IES photometry file may be given. No input is accepted on STDIN.
The output image in HDR format is produced on STDOUT with the default dimensions of 1024 by 1024 pixels. The dimensions may be overwritten with the −d dimensions option which takes an integer that is divisible by two.
To render a four−view image of photometry file ABC123.ies and save the result to luminaire.hdr
ltpict −i ABC123.ies > luminaire.hdr
To render a small four−view HDR image of the RADIANCE luminaire XYZ456.rad to STDOUT, and display it with ximage
ltpict −d 400 XYZ456.rad | ximage
objline(1), objview(1), objpict(1), ies2rad(1), ltview(1)