I was working on another try to use blend4web for a personal application, and I remembered that if you want to use an environment map it has to be a Blender specific 2 rows cubemap ( 2*3 cubes faces).

I’ve found ways to make it with gimp, after using Bruno Postle’s panotools script ( erect2cubic Erect2cubic ), or directly inside Blender (link 1: Blendswap cubemap maker , from : cubemap making inside blender).




But all those ways needed to treat each panos one after the other; too long when you have to transform 20 panoramas…
So I wrote a little bash script to transform equirectangular panoramas initially to those specific cubemaps, then I extended it to match further types of cubemaps ( it seems that unity uses cross styled cubemaps ).

#!/bin/sh
# 2016 11 03 sh script
# This script aim to transform an equirectangular pano to a cubemap image used for environment mapping
# it uses : Hugin, Bruno Postle's panotools scripts (perl) ,imagemagick's "convert" and montage command line tools and zenity for gui.
# Find it useful ? Any bugs, ideas?, mail me at : mail@fabkzo.com
# Author: FabKzo www.fabkzo.com

pano=0
order=0
front=cube0000.tif
right=cube0001.tif
back=cube0002.tif
left=cube0003.tif
up=cube0004.tif
down=cube0005.tif

createPano (){
                    #create pto file
                    erect2cubic --erect=$pano --ptofile=cube.pto;
    
                    #create each cube faces
                    nona -o cube cube.pto;
                    imgsize=$(identify -format %h cube0000.tif);
                    echo $imgsize;
                    }
blendercubeMap (){
                    convert $left $back $right +append cubeUp.tif;
                    convert $down $up $front +append cubeDown.tif;
                    convert cubeUp.tif cubeDown.tif -append toTo.tif;
}

horizontalcross (){
                    montage null: $up null: null: $left $front $right $back null: $down null: null: -geometry $imgsize -background none -tile 4x3 toTo.tif;
}

verticalcross (){
                    convert -rotate 180 $back $back 
                    montage null: $up null: $left $front $right null: $down null: null: $back null: -geometry $imgsize -background none -tile 3x4 toTo.tif;
}

horizontalline (){
                    convert $right $left $up $down $front $back +append toTo.tif;
}

verticalline (){
                    convert $right $left $up $down $front $back -append toTo.tif;
}
                    
finalsize=` zenity --entry --title="Enter Cubemap final height in px" --text="height" --entry-text="4096" `
final=` zenity --list --radiolist --title="3D software cubemap type" --column="Choice" --column="Cubemap"\
                        TRUE "Blender" \
                        FALSE "horizontal-cross" \
                        FALSE "vertical-cross" \
                        FALSE "horizontal-line"\
                        FALSE "vertical-line"`

                case $final in
                        "Blender")
                        order="blendercubeMap";;
                        "horizontal-cross")
                        order="horizontalcross";;
                        "vertical-cross")
                        order="verticalcross";;
                        "horizontal-line")
                        order="horizontalline";;
                        "vertical-line")
                        order="verticalline";;
                        
                        *)
                    esac

while [ $# -gt 0 ]; do
    pano=$1
    echo $pano
    echo "createPano"
    
    createPano
    
    
    #takes each face to create the final image
    $order
    
    convert -resize x$finalsize toTo.tif ${pano%.*}-cubemap.png
    
    rm cubeUp.tif cubeDown.tif toTo.tif cube????.tif cube.pto
    
    shift
    done
    zenity --info --text="DONE"

Pass it your panos, then it should result in a lot of .PNG cubemaps ready to use to create game assets inside blend4web or blender game engine ( first option ):

examples :

Feel free to use those examples and tell me back if I’ve done an error on the other outputs or if you encounter problems to use it . Linux only . Enjoy it , share it .