The Pixel Crush

-------------------------------------------|Digital Animation & Game Criticism|-------------------------------------------

Saturday, 17 March 2012

Verte Vertices

I've been having real trouble with the render times in the green house which has meant turning down the subdivision levels on the smaller plants where its unnoticeable, deleting backfaces on the moss, and then performing reduce functions on the whole lot as a combined mesh. Messy but really effective as the scene now runs a lot smoother in the viewport.

Now lets rewind in time as I have another shot that I haven't talked about.
Seeing as the elements in this scene are quite close proximity to each other in terms of depth I wanted to pick out the outlines of Leonard with a rim light and make the pillar in the foreground a little darker to pull attention away from it.
Bounce lighting was harder to fake in this shot as the point where the sun hits the floor is in view and therefore placing spotlights looked wrong as their cone is clearly visible as seen in the above render. Something I saw in a killzone cinematics breakdown video recently was the use of volume lights to amazing effect for broader strokes of colour or light, perfect for cheating this kind of thing, so I plan to play with those at some point soon.
I accidentally deleted the shaders for the oxygen tank and the pipe isnt in shot here so it needs a re-render anyway but this is pretty close to the final lighting for this shot.

First thing that needed doing was to finally lay out the wonderful plants Ryan and Nigel had modelled into their positions on the flowerbeds of the greenhouse.

It was time to start the greenhouse lighting as the final props and set stuff for that was just falling into place and so I decided because it was an exterior scene it was important for me to be able to use proper final gather to get that realistic outside look. I started by creating a giant sphere to encompass the entire greenhouse and plugged Charlie's concept art from the beginning of the project into the incandescence value of the sphere's shader. This means that with final gather enabled it looks at the colour information of the sphere's incandescence and proceeds to light the scene accordingly which is a fantastic starting point, especcially as it was concept art of the city, so it should fit nicely in the final composite. I made a cube with some holes to let light in to test the set up:
Then I added a spotlight for the sun to see how much lightness it added, what angle might be good, and how far I needed to position the light away to get interesting shadows.
I then imported the scene and applied a lambert to the whole thing and got this fantastic result, isn't it gorgeous!? This is from nothing but indirect final gather lighting from the sphere.
With textures the result is still nice but you don't get the same effect of soft light and colour. So from I here I tweaked a lot of shaders and Jake helped by desaturating and re-colouring some of the textures to better match the pastel tones of the original designs that Charlie had made. Great as the plants look some of them had never had textures made for them so I had to bodge it by assigning different coloured shaders to different bits of geometry and using procedural maya textures for bump maps, not ideal, but not the end of the world.
With the sunlight turned back on this is the result, and while the hard sun light doesn't match the dingy weather outside with a few tweaks I felt I could be on the right track.
First I needed to fix something that'd been a problem for a while and texture it properly which was the glass and pipes of the greenhouse itself. Glitchy reflections had been bugging this shader forever and I thought I had fixed it with a weird combination of backface culling and solid refractions in the mia_material. I was wrong, it turns out after lots of fiddling and rendering it was the glass trying to refract itself, which is easily fixed but telling it not to show up in reflections.
Then I textured some mossy algae stuff around where the pipes intersected the glass and some dirt and scratches from flying debris that had tarnished the glass between pipes from the outside. Getting the alpha channel for this texture to work properly took forever. Apparently the cutout opacity thing I found before doesn't work because that literally cuts out the shader, not just the texture on its surface so I lost the refractions as well as the texture: no good.

After some deep thought I realised the using the transparency channel wanted the opposite information of what an alpha matter wanted and that was the reason it wasn't working, the mia material wants white where it shouldn't be transparent and black where it should be opaque. I can't remember how I figured that out but there was logic in the somewhere. Anyway it worked:
Also another problematic shader: The moss hanging from the pipes. Apparently called Spanish Moss. This one looked gorgeous with the mia_material and the translucency properties set correctly with a small amount of transparency but as soon as it tried showing things that first been refracted (the entire greenhouse) through its alpha outline it started glitching out with coloured and ugly pixely silhouettes.

I couldn't find a fix for this after ages and so resorted to a lambert and achieved a similar effect but it seemed incredibly slow to render so hopefully that won't come back and screw me over. At least it fixed the awful glitchy refracted alpha situation. 
Here is a breakdown of the greenhouse lighting as it now stands with the coloured lights for each bed of flowers to aid the sense of a colour gradient from one type to another (above).
Then the lamp lights which I think I have now localised so they look more like bright spots in the greenhouse rather than just a general yellow glow.
Then the dull light of the sun. Not sure what to do about this, I think I might try and frame the tree as if the sun is shining in a shaft between two towering buildings and just illuminating a strip of the greenhouse with its light.

Have some renders. So far too bright, too cluttered and before the optimisations this took 19 minutes. I like the colours though. Click to enlarge.
This one has a glitch on the hanging moss where I forgot to tell the greenhouse glass to transmit transparency so its not showing whats on the other side of it to the moss I think. Its either that or transmit refraction. This is a nice render with the sun on the tree and I think depth of field will do wonders for breaking up the overwhelming detail of the scene. Its still missing something though, in terms of lighting. This render took about 40 minutes originally, but its now below 10 which is my render threshold. Amazing what a little optimisation can do.

Pixel Propaganda

A great looking short called ruin. I mean really great looking. Unofrtunately its story is pretty non-existant and what is there is ripped straight from genericness, but its gorgeous and short so...

This is a trailer for a game where al the props are handmade in reality, the first stop motion platformer?

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