Thanks Greg! Iām sure that I did something silly when it went through `pfilt`

. I havenāt had time to retest, but Iām sure itās a non-issue.

Thanks for the tip on running it via a `saved.opt`

. Everything works successfully! I have updated the link at https://thinkmoult.com/vr/ and it now shows two: one for the cube and one for the equirectangular. I did a very fast low quality render just as a test and it works great!

I have also modified `3d360.cal`

to fixed the horizontal flip issue by changing `px = $2`

to `px = XD - $2;`

. I also created another version of the file called `2d360.cal`

in case you only want to create a single image, instead of an over-under stereoscopic pair. Here it is:

```
{
2d360.cal
Definitions for full 360 equirectangular projection
Originally based on 3d360.cal (c)2014 Mark J. Stock
Modified 2018 Dion Moult for a mono instead of a stereo image
Use it like this:
X=2048; Y=1024; cnt $Y $X | rcalc -f 2d360.cal -e "XD=$X;YD=$Y;X=0;Y=0;Z=0" | rtrace [rpict options] -x $X -y $Y -fac scene.oct > out.hdr
Parameters defined externally:
X : -vp X coordinate
Y : -vp Y coordinate
Z : -vp Z coordinate
XD : horizontal picture dimension ( pixels )
YD : vertical picture dimension ( pixels )
}
{ Direction of the current pixel (both angles in radians) }
px = XD - $2;
py = YD - $1;
frac(x) : x - floor(x);
altitude = (frac((py-0.5)/(YD)) - 0.5) * PI;
{ to do over-under stereo, azimuth is easy }
azimut = px * 2 * PI / XD;
{ Transformation into a direction vector }
xdir = cos(azimut) * cos(altitude);
ydir = sin(azimut) * cos(altitude);
zdir = sin(altitude);
{ Output line to rtrace; each ray needs: xorg yorg zorg xdir ydir zdir }
$1 = X; $2 = Y; $3 = Z;
$4 = xdir; $5 = ydir; $6 = zdir;
{ EOF }
```

I have written up an article about how to use Radiance to produce the three types of 360 panoramas: sphere maps, cube maps, and equirectangular projection, based on what I have learned in this thread and thanks to all your help! I hope this is useful for somebody:

https://thinkmoult.com/create-360-vr-panoramas-with-radiance.html