I got tired of slaving away for Bob's Floating Spheres and decided to punch up my demo reel with hopes of landing a Compositing job at Flixar (Pixar's evil twin.) So I pulled the Toy's project off the CD, if this doesn't show who can composite nothing will! (The project is attached to this post, download it, copy the Toys project off your CD (/HASH2005/Data/Projects/Toys) and put the project file in the same directory as Toys.prj)
I added a few lights to the shot to simulate Radiosity: a cieling bulb a bulb for each wall and a bulb for the floor. all these lights have specular components, but only the ceiling bulb casts shadows. This is in addition to the lights already in the shot.
I have left the lights pretty raw in their intensity and colors, knowing that I will be compositing them later anyway. The resulting render (at one pass multi-pass) looks like this:
I'm pretty sure I can work with this, so I load up the EXR into a new project and look at the buffers:
Crimeny that's a lot of buffers... and if the simple spheres i was doing for bob wound up with those big long complicated composites, this here will be
... I don't even want to think about it. This is the thing that will get you with composites: The amount of raw data you get to play with is at once amazingly powerful and pretty darn complicated.
So can we do anything to make this a more manageable set of Buffers? You bet your sweet bippy there is. The secret to dealing with any complicated task is to compartmentalize it to the point where you have manageable chunks. For light buffers this means we need to start thinking about what lights can be grouped together with what other lights and adjusted all at once (here we come to the age old trade off: Fine Control vs. Ease of Use the more we simplify the buffers the more fine tune ability we will be giving up.)
The first step is to create some groups for our lights. by default we already have one, you don't see it in the PWS or anywhere else simply because all the lights are in it (making it pretty pointless
) These groups are called Light Buffer Objects, which may sound familliar, if you will recall from back in the starting simple thread, one of our rendering options was Light Buffer Objects.
A Light Buffer object is part of a choreography, so logically we create one by bringing up the contextual menu for the Chor.
And we choose Insert Light Buffer.
Upon doing this you will now see in the PWS a light buffer object folder and under it two sub folders called Light Buffer 1 and Light Buffer 2. Light Buffer 1 contains the last light listed in the chor and Light Buffer 2 contains all the other lights in the scene. If we were to render this out now we could choose the Light Buffers Objects buffer type (rather than the each light in it's own buffer type) and we would have two sets of buffers rather than the 9 we started with. that's a pretty drastic reduction in buffers. probably a bit too drastic really
but it's a start. So we already have one light in the Buffer 1 and it happens to be the light I added to simulate light bounce from the ceiling. Now we need to decide if there is going to be any lights that we would want to group with this particular light... we could for instance just drop all the radiosity bulbs that I added into a single light buffer and increase the room bounce as a unit... but I don't particularly like that option. I want to be able to adjust bounce in a logical way that reflects the motivated light in the scene. I think the only light I would want to add in to this buffer would be the one for the wall that is not in direct light from the key (the one over on screen left.) simply because it will be the one light to share the relative intensity of the ceiling's bounce. SO I figure out which light it is (now actually would be a great time to go through the chor and rename all those shortcuts from names that tell us nothing: Shortcut to Light 6 (3), to names that mean something: RearWallBounceLight) and I drag the shortcut in Light Buffer 2 up to light Buffer 1, this will move that light into the same group with the ceiling bounce light. I then rename that buffer object so that I know what it is later:
So now we look at what we have left... Two Floor Bounce Lights, One wall Bounce, one Key, and three fill lights.
we can use the same logical deduction we used for the other two bounce lights to determine if we want to group any of these lights together. I'm eyeing those bounce lights... that would be a good thing to adjust as a unit I think. the key really should be on it's own so we want to give that it's own buffer.... the fill lights... Hmm well I might be tempted to put them all together but the blue colored klieg I named Cool Fill has shadows that it casts... the other two fill lights do not... so lets divide the lights along those lines with two fills in one buffer and the Cool Fill in a second:
This will leave us with 5 light buffers to composite with, which is almost half of what we had originally, not a bad savings. So to review: we added light buffer objects for each logical grouping of lights in our scene, we then assigned those lights to their respective buffers. Everything was renamed to make it more legible. Now it's time to render.
We set this render up like we did for the Starting Simple project. with the exception that we chose the Light Buffers Objects type instead of the Each Light in it's own buffer type:
Ok I'm going to put this on to render and get back to work on my cover letter for Flixar, once they see my work I just know my Hollywood dreams will come true!