The Irradiance map viewer can be used to view, merge and save light map files created by V-Ray. It works with Irradiance maps and Light Cache maps.
Overview
The Irradiance Map viewer tool allows you to navigate around a 3d projected version of a scene to view where GI samples were taken during the rendering process.
Note: The viewer is a separate program and does not require the V-Ray host application (3ds Max, Maya, MODO, etc.) to be running.
Installation
The Irradiance Map viewer tool is installed along with V-Ray for 3ds Max. To access the Irradiance Map viewer, go to:
Start Menu > Programs > V-Ray for 3ds Max > Tools > Irradiance Map viewer for Windows 10 and earlier.
Start Menu > All apps > V-Ray for 3ds Max > Irradiance Map viewer for Windows 11.
Start the imapviewer executable from:
C:\Program Files\Chaos Group\V-Ray\3ds Max 20xx\bin for V-Ray for 3ds Max 2021 or earlier.
C:\ProgramData\Autodesk\ApplicationPlugins\VRay3dsMax202x\bin for 3ds Max 2022 or later.
There are several methods of running the irradiance map viewer, which are outlined below. The simplest way is to double-click the imapviewer.exe file. This will bring up an Open File dialog box that lets you browse for a light map to open. This is the same as starting the irradiance map viewer from the Start Menu. The menus of the program allow you to do various things with the light map (merging and saving, etc). You can also run the irradiance map viewer from the command line. In this case, there are several possible choices: If you type just > imapviewer on the command line, this is the same as double-clicking the file. It brings up the File Open dialog for selecting an irradiance map or a light cache map file. You can also type > imapviewer <filename> where <filename> is the name of an irradiance map or a light cache map file. This file is opened automatically. A third way is to use the viewer to merge several maps into one: > imapviewer -load <map1> -load <map2> ... [-save<finalmap>] [-nodisplay] This loads the specified maps and combines them into one light map of the same type. If the -save option is specified, the result is written to the given file. If the -nodisplay option is specified, the resulting map is not displayed (otherwise, the viewer displays the final result). [-incremental] -load <filename> {-load <filename>} [-save <filename>] Merges the specified irradiance/light maps and writes them to the specified file. If the -incremental option is specified, the imapviewer discards samples that fall in areas where there is already sufficient information. This option must be specified before any -load options. Usage
Options
Option Description -info Prints out information about the current irradiance map. -noDisplay When this option is specified, the resulting map is not displayed (otherwise, the viewer displays the final result). -up_axis [z|y] Chooses the up axis (default is z). -convert <filenameFrom> <filenameTo.pts> [-rgb] Converts the irradiance map file into a PTS file. -help Prints a help message.