Well... let's start!
my first request for a missing feature is... just like Jeanphi know... is the possibility to play with the image used as environment background!
at time in LuxRender is not possible to rotate, flip, tile the used image around any axis! so... let my explain why this feature is so important!
when we work with a normal fixed shoot... my request have not much sense... but when we load an 360°panorama image... the limitation of Luxrender are visible.
for example I use sibl illumination... the nice thing is that you need an 360° background image.. and a sun(for exterior) or light sources(for interior)!
the plugin import the sibl data for the image.. and create a sphere and the needed lights and/or environment background in the scene! according to the used rendering engine! and according to the enabled task and mapping in the sibl-gui!
as 3ds max user I have not only the bridging script that support sibl-gui... but more than one template to work with! but for Luxrender I must edit in hdrshop the background image! to match what I see in 3ds max view-port with the real environment image portion rendered from Lux!
I do all this task manually and it's a great job, and the result is not precise... since I have to synchronize the sun in the scene and the unpredictable sun position in the rendered image! obviously they are correlated... they must work together to recreate the correct lighting and shadows! and also... I can't play with max cam... I must use that edited image. If I want to change camera view... I must edit again the backgound image... so to make it match with all the rest.
I saw in the past an opened task for sibl support in mantis...
this request is also related to that task!
just go to: http://www.luxrender.net/mantis/view.php?id=780
if anyone is interested in more info about sibl illumination and free software:viewtopic.php?f=33&t=3521&p=37636&hilit=sibl#p37636
I read in the hdrlab forum... that they want to create a script and template file to bridge "sibl-gui" with blender! If any one with the skill want to help... is welcome! all the suggested software are free and cool! one of than is the well known "picturenaut"... exr/hdr editor/converter.