I've run into a bit of a problem: I'd like to render a top-down isometric view (showing the layout and surfaces of all in the worksite), but when there's no covering blocking abiant light (when I exclude it form the 3d view), everything is 'blown out' by the ambiant sunlight shining through the hole that is the no-ceiling... yet I want that light to shine in through the -windows- of the top-view, but not from above.
It seems that there is no material I can create that will both allow one to see through it -and- block ambiant light (defying the laws of physics, what), and I've tried creating a story above and creating a 'floor' there to see if that affects the render... to no avail.
Does anyone have any suggestion about how to get around this?
PS: I even tried to make a reflective, but transparent surface (sort of a 'polariser')... no dice.
Here's another one I rendered last night: I got to there by putting a slab over the sunlight object, and a wall above that, all 'painted' in a custom matte black no-reflect surface... still getting some 'parasite' sunlight over the top, though. I think it -is- possible, though I wish there was an easier way.
It would be nice to have an object/slab setting that would tell it to 'behave' normally (reflect, block light, etc.), but just not show in the render.
I'm not sure it is possible at the moment ... I wish GS implement this functionality soon ... It's a must when you do interior renderings. It is very helpful technique to have good perspective (I mean not so distorted perspective)
I managed to get pretty well the effect I wanted, through elimnating all sunlight and replacing that with 'sun objects'.
I'm a photographer, so delved into my bag of studio techniques to come up with this: almost all the top and bottom area of the white field around the model is a 'neo-hidden' slab whose altitude is -just- above the window opening and inches away from the outer wall... the top surface is a (custom) white matte with all reflectivity turned off, and the bottom and sides are a (custom) non-reflective black matte. We use polysterene panels exactly like this in studio photography.
Directly underneath it is a directed sun object that uses 'global light' and 'in one direction only' illumination settings.
With this I got totally black wall-tops... which was initially what I wanted, but the end result seemed a bit 'stark', so I added a 'global' light around eight metres above the scene, set with 'no falloff' and 'no shadows'... that illuminated the wall-tops/moldings and cabinet-tops enough to show what they were (without leaving a black 'hole' as they were without this light).