Anvanced Seperate lighting chanels - for Post editing... DO IT :)

[Free Agent_cg]

a more defined lighting chanel (like the z depth channel) that you can select (in photoshop) the area that a light effects, accuratly enough that with some photoshop level changes you can edit it enough to make it apear that the light was never on to begin with.

further it would probably be even more helpful if there were separate chanels for each light... and im really pushing it now (muhahahaha) but give them a .PSD output so u can save all the layers separately within ONE file (perhaps tiff would work similarily???)but i understand if this isnt considered as it doesnt accomodate and those silly non-photoshop users

can i get fries with that?

[thomthom]

Re: Anvanced Seperate lighting chanels - for Post editing... DO IT

I'll have an Extra Large please. (a.k.a. Ditto!)

[dalomar_cg]

Re: Anvanced Seperate lighting chanels - for Post editing... DO IT

hmm...how do I say this...you just can't do that in the way that your asking...

In order to really do what your asking to do ("remove" a light) you really can't work from a finished render and a single channel. Why?...the final result that you get when you render is a combination of multiple aspects of an image (diffuse, GI, reflection), and the result of the lighting channel isn't meant to be "combined" with just the final image.

What you need to do in order to have the ability to "remove" a light is you need to assemble the render from the ground up with all of the components to the rendering (gi, lighting, reflections, refractions, diffuse). Only then can you really begin to adjust individual components of the rendering and make the kinds of tweeks that your looking for. This process is what is referred to as render compositing.

The bad news is that you don't have all of the channels that you need to do this in the public version, but the good news is that we have added the necessary channels in our internal builds.

As far as your comment of having a "more defined" lighting channel, that is impossible. The channel is what it is because of how it needs to be to solve the rendering. Making adjustments to that channel would actually throw off the compositing process that I briefly explained before, thus making it impossible to achieve the actual rendered result from the composite (and that would actually be a very bad thing).

As far as channels for every light, I'm not sure of the possibilities for us to add that, but I wouldn't hold your breath. The channels that we have added were exposed to us by the chaos group, and I would imagine that if the didn't have it or make it available to us, then there probably isn't a way for us to stick our head in there and do it ourselves (sorry).

You can get a channel for every light, but you'd have to render a regular pass and then a pass for each light. Luckily, you don't need any GI for the extra passes or any fancy render features like reflections or glossiness, so basically you can get all those channels out in a minute or two.

Hopefully that explains the technical side of things a little more. If you want some more info on channels and how they get put together, take a look at the example page from Spot3d.
http://www.spot3d.com/vray/help/150R...erelements.htm

[Free Agent_cg]

Re: Anvanced Seperate lighting chanels - for Post editing... DO IT

damn i was expecting a: sure guy great idea i'll get right on that!! (2 thumbs up)
but i'll settle for you answere :'(

however in that spot3d example the raw lighting channel is more "defined" what i mean is its not the pixelated black and white we get from a lighting channel, its graded with greys.
and my initial request was actually a sneaky way of requestin multilights (as in maxwell AND fryrender), where the render output has seperate passes for each light and with their built in post processing platform/interface they can control the strength of each.

however (a little speculation) both maxwell and fry use a brute force renderer like DMC (remember... speculating here) and i havnt really worked with DMC too much (not enough to know what kind of lighting channels it producess) but i understand Irradience Map shoots a certain number of photons and then guesses what the photon next to it would read, hence its speed, would that be why we get such crappy lighting channels?

fell free to let me know if im way off and set me straight...

[dalomar_cg]

Re: Anvanced Seperate lighting chanels - for Post editing... DO IT

Sorry for the less than expected answer, but thats what it is...actually, doing full composites is pretty flexible, so once you get into messing with them you'll get convinced. My explanation of the process above is not portraying as good as it really is. Compositing is what makes really advanced vfx go 'round, so it definitely holds alot of potential.

The thing you have to keep in mind is that all of the channels may not be as defined as expected. When it comes to image sampling, its based on the final RGB result, not the channels that make it all up. So with things like shadow channels and GI channels have the capability to be undersampled because of that. The best way to get around this is to have better antialiasing, and in the case of the lighting channel add some subdivisions on the lights.

I knew that you were asking for a "multilight" thing, but there's much more that happens then just channels. The render process that Maxwell and Fry use is whats called Progresive Path Tracing, and basically the rendering can be saved as an image, or as the traced light path structure that generated the image. This is actually what multi light is using, not a channel for each light, but its actually making adjustments to the path structure.

V-Ray has a progressive path tracing mode (its in LC), but it doesn't save the raycasting structure or have a way to modify it like multilight (in fact PPT won't even generate channels info). With separate lighting channels, you really can get something close, but its just not going to be as accurate.

[Free Agent_cg]

Re: Anvanced Seperate lighting chanels - for Post editing... DO IT

ok great thanx for all that... how about that order of fries?