I'm playing around with Luxrender, and there are a few scenes which have me scratching my head for an easy fix. 

The scene is Arrin's Design 14.  There are windows, but by default they show a sky image and don't allow light through.  The issue using Luxrender is that when I make it all transparent in Lux, it isn't transparent in the PNG image created.

I tried:

Visible in camera - checked

Visible in Raytracing - unchecked

Casts shadows - unchecked

The idea was a render with sunlight coming through.  If I use a hemisphere, that will block the light too.  Ideas?  What am I doing wrong?

http://www.renderosity.com/mod/bcs/design-14/96559/

Attached Link: Indoor scene and IDL

can't advise on lux, but BB's envsphere don't block inf lite (sun).  one of us would probably have to own that item to tell you more.  if there's mat zone for windows, make them transparent.  poser can't project img thru surface (coloured transparency) in PP2014 and earlier, but maybe lux can.

In 2014 and earlier...  Did you mean a version like 2012, or it can't do it at all?

no, they haven't added it yet.  as of PP2014 SR 4.

Isn't that known as caustics? I get confused on those terms.

     Assign a glass material to the windows, at least in Lux;  in Poser, they are apparently not transparent but textured with a faux exterior view image (not uncommon with Poser props).

     If you want this effect in Poser, try using an image map for a spotlight light gel.

they sometimes include transmissive fx like transparency colour as part of caustics, but in carrara it works without enabling caustics, e.g. stained-glass window.  my guess is that lux does it well.

Gator. what are you useing to port the scene to lux?

Reality.  I took a bit of a break from Poser, but back at it.  Trying again with Firefly and experimenting with Reality/Lux.

I think the best way to do what you want is to remove the textures from the glass in posers, then in reality use a glass material and IBL rather than a sun. You don't need a sky dome. Reality will simulate one.

In poser try swtiching the windows to bb's glass and use his environsphere and IDL.

Thanks.  I'll try the envirosphere.  I haven't gotten back to reality yet, it renders so agonizingly slow.  And I have a pretty good computer too - i7 quad core with 16 GB RAM.