Hi there - I'm the person trying to render for largescale output (36 x 9 ft)!!! And I'm not getting much sleep. I have ANOTHER specific rendering question - would be very grateful for advice (as usual)... In a previous thread I asked - 'Is there a way I can render specific objects WITHOUT also rendering the sky? - whilst retaining the correct lighting on the object/figure I am rendering?' Agiel answered that: "it is possible to render 'selected objects' with multi-pass rendering checked, and only render the object masks for the selected objects. Using the masks with the render will allow you to ignore the sky. If you have reflections, you can also render the scene normally with the object mask selected." Unfortunately I haven't worked out how to do this. Could anyone explain to me the steps to achieve this. sorry I'm relatrively ne to Vue thanks... j

In your render settings, check the "enable multi pass" box, and in the multipass options, choose the object mask for the object you want isolated. I will be rendered over a black background with correct lighting. Now, render your image, and click on the little g-buffer icon in the render window header. your mask will show up there, then just save it.
But you will have to make a complete render (beauty pass) of your scene first.

So is it possible to render a specific object at a higher resolution than the rest of the render? And the other problem is I am rendering to disk beause the resolution is too high to render to screen. Is what you describe still possible?

So far the only way I can do something like this is to select the object on the layers panel on the main screen - then go to Render/render options/render only selected objects and then render but this way although it renders only the one object it also renders the sky, which takes a lot of time

You can render to disk, but the object mask will be the same resolution as the render. You will have to create a file for the object mask to be saved to.

The problem is if I have to render the whole scene at the same resolution it will take weeks to render! So there is no way to get rid of the sky...? Is the only way to mask out areas (eg. the sky) to create an alpha plane directly in front of the camera and an alpha mask to mask out areas I don't want to scan? ie then I could mask out most of the sky (to speed up the render?). Pete suggests you can use masks in this way in his tiling tutorial http://www.petes-oasis.com/tilerendering. I have tried this and it works - i wondered if there was a simpler way.

Went to the page you mentioned, but didn't see anything related to alpha planes. 
There is no way to get rid of the sky without alphas. What you can do is render a scene with only your object and sky, and use the global alpha to mask out the sky, don't forget to check "hide infinite plane from alpha", or you'll get the ground plane visible in the mask.

http://www.petes-oasis.com/tilerendering Bruno it says the following: Ok we are going to use the alpha plane mask idea here. It has some quarks so we'll take it all one step at a time: The advantages of this idea here are really excellent. 1/ First is to plan out how many pieces you want to render your image in and build the masks accordingly. Chances are you're going to be rendering to disk anyway because the render will be too big for the screen. How many pieces? Well how well does your computer run? The worse it runs the more pieces you should render. It will make the renders smaller and you loose less of the final render should something go wrong. To make the masks make a picture in the same shape and size as your final render. Like if it's square make a square image if it's going to be rectangular make it the same. You can make it 1 to 1 size but make sure you save it as a 8 bit bmp instead of 24 bit because it will take up tons less space on your computer. Full sized is probably best because then you have maximum control over creating the masked areas. Important ! Do not try to make the mask perfect ! Your rendered images will fail. It's impossible to get the mask sitting in Vue exactly perfect so plan on having the rendered areas bigger than they need be by about 10 or 20 extra rows. i.e.: Your going to render a monster picture 5000 X 5000 in 25 squares. Don't make the squares 1/5 th (1000 X 1000) of the render area because you can't get the mask sitting in Vue perfect. Make them bigger 1050 X 1050 would be a better idea so that 50 extra pixels always get rendered extra. It's very important to render more than you actually need. Render in long strips right across the entire image if you can instead of boxes because it will actually render faster that way. If you can't though because the resulting strips will be too long then render boxes instead. I did boxes here just to prove it could be done. Don't render vertical strips, it will render really slow. Use horizontal strips instead, the same direction Vue renders. This will be the way that renders the fastest because Vue will almost completely ignore the masked parts. ny, you are just going to reload a new mask on top of it. 2 Second load your winner scene and then click on the camera. Very important ! This is very important because when you make the new alpha plane you want it be sitting exactly on the camera. Then you only have to move the mask forward a bit. You don't want to have to drag or resize your alpha plane any. You don't want to have to drag the plane half way across scene because it got created somewhere else. It has to be sitting perfectly square to the camera. The easiest way to ensure that it is, is just create it at the camera spot in the first place. You just want to create it and move it slightly forward in front of the camera so it completely covers the rendered area as best as you can place it. You can't get it sitting perfect so that's why you are over rendering the spot to compensate for this. etc... I guess you could use the same technique to mask out specific areas?

Oh, I think I see what this means, it's like tile rendering, and rendering one tile at a time, a bit like Hypervue does across a network of computers, and composite them all in a paint program.
You won't be able to mask precisely your object this way, and even if you do, Vue will still compute the atmosphere, even if it won't show, because for Vue, your mask isn't a mask, it's an object that is rendered inside a whole scene. Maybe it will be alittle faster, but I doubt you'll get good results, and you will still need to mask out your object in a paint program afterwards.